Thèses : « Isopets »

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Brunet, Johanne. « Sex ratios in terrestrial isopods ». Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66212.

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Rogachevskiy, Andrey Valerievich. « Production and trapping of Na isopes for [beta]-decay studies ». [S.l. : [Groningen : s.n.] ; University Library Groningen] [Host], 2007. http://irs.ub.rug.nl/ppn//303494689.

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Monteiro, Marta Sofia Soares Craveiro Alves. « Cadmium phytotoxicity and trophic transfer to isopods ». Doctoral thesis, Universidade de Aveiro, 2008. http://hdl.handle.net/10773/962.

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Doutoramento em Biologia
O cádmio (Cd) é um metal não essencial e é considerado um poluente prioritário pela comunidade europeia. Este metal atinge o ambiente no decurso de várias actividades antropogénicas e tende a concentrar-se nos solos e sedimentos, onde está potencialmente disponível para as plantas, sendo posteriormente transferido através da cadeia trófica. Neste contexto, o principal objectivo da presente dissertação foi o estudo dos efeitos da assimilação e da acumulação de Cd em plantas e as suas consequências para animais consumidores. Numa primeira fase, foram estudados os principais efeitos fisiológicos e genotóxicos do Cd em plantas. As plantas de alface (Lactuca sativa L.) expostas a Cd apresentaram um decréscimo na eficiência fotossintética, aumento de peroxidação lipídica e alterações significativas na actividade de enzimas de stress oxidativo. Estas alterações culminaram num decréscimo do crescimento da parte aérea no final da exposição. As respostas obtidas pelos parâmetros bioquímicos sugerem que estes poderão ser utilizados como eventuais biomarcadores em testes ecotoxicológicos com Cd em abordagens integrantes em conjunto com parâmetros clássicos. Os efeitos mutagénicos de Cd foram avaliados através da determinação da instabilidade de microsatélites (IM). Não foi observada IM, nem nas folhas nem nas raízes de plantas de alface com 5 semanas de idade expostas a 100 μM Cd durante 14 dias, no entanto observou-se IM em raízes de alface exposta a 10 μM Cd durante 28 dias desde a germinação. A idade da planta e a maior acumulação de Cd nas raízes poderão explicar os resultados obtidos. A clastogenicidade de Cd foi analisada em três espécies vegetais com diferentes capacidades de destoxificação e acumulação de metais através de citometria de fluxo. Foram detectadas alterações significativas nos parâmetros analisados em raízes alface, mas não nas espécies Thlaspi caerulescens J & C Presl e Thlaspi arvense L. Estes resultados sugerem que o stress provocado pelo Cd originou clastogenicidade como consequência da perda de porções de cromossomas, uma vez que o conteúdo de ADN nuclear diminuiu. A transferência trófica através da cadeia alimentar permanece muito pouco estudada em termos ecotoxicológicos. A distribuição subcellular de metais num organismo pode ser utilizada para compreender a transferência trófica de um metal na cadeia alimentar. Como tal, numa última parte é estudado de que modo a distribuição subcellular do Cd em plantas com perfis de acumulação de Cd distintos afecta a biodisponibilidade e transferência trófica de Cd para isópodes. A distribuição de Cd entre as 4 fracções subcelulares obtidas através de centrifugação diferencial revelou a existência de diferenças significativas entre as espécies de plantas. Estes resultados em conjunto com a avaliação directa da eficiência de assimilação (EA) de Cd individual de cada uma das quatro fracções subcelulares das plantas em estudo, resultou em informação de grande relevância para a explicação das diferenças observadas na EA de Cd por parte de isópodes alimentados com folhas de diferentes espécies de plantas. Com base nos resultados obtidos, o Cd ligado a proteínas estáveis à temperatura (e.g. metaloteoninas e fitoquelatinas) é o menos biodisponível, sendo assim o que menos contribuiu para a transferência trófica, enquanto que o Cd ligado a proteínas desnaturadas pela temperatura foi a fracção mais disponível para transferência trófica de Cd ao isópode. Estes resultados realçam a relevância ecológica da distribuição subcelular de Cd em plantas que tem influência directa na tranferência trófica deste metal para os consumidores e ainda o facto de que alterações na distribuição subcelular de Cd em plantas devido a diferentes mecanismos de destoxificação poderá ter um impacto directo na transferência trófica de Cd para o animal consumidor.
Cadmium (Cd) is a non-essential metal and is considered a priority pollutant by the European Community. This metal is released to the environment as a consequence of several anthropogenic activities and tends to accumulate in soils and sediments where it is potentially available to rooted plants causing severe detrimental effects and then transferred to animals through the food chain. In this context, the main objective of the present dissertation is to study the effects of Cd uptake and accumulation in plants and its implications to animal consumers. First, the main physiologic and genotoxic effects of Cd to plants were examined. Cadmium-exposed lettuce (Lactuca sativa L.) plants displayed a significant decrease in photosynthetic efficiency, enhanced lipid peroxidation and alterations in the activities of antioxidant enzymes over the duration of exposure. These alterations culminated in reduced shoot growth at the end of the exposure. The aforementioned biochemical alterations are suggested to be used as plant biomarkers in integrative approaches with classical endpoints in future ecotoxicological tests with Cd. The mutagenic effects of Cd on plants were assessed examining microsatellite instability (MSI). No MSI was found neither in leaves nor roots of 5-week old lettuce plants exposed to 100 μM Cd, but MSI was found in roots of lettuce plants exposed to 10 μM for 28 days from seed germination. The age of the plant at the time and the higher accumulation of Cd in the roots might explain the results obtained. Clastogenic effects of Cd was examined in plants with different metal accumulation and detoxification capacities by flow cytometric (FCM). The endpoints analysed indicated significant alterations in lettuce roots but not in Thlaspi caerulescens J & C Presl and Thlaspi arvense L.. The results obtained suggested that Cd stress may have lead to clastogenic damage as a consequence of loss of chromosome portions because nDNA content was found to be diminished. Trophic transfer through the food chain remains a largely unexplored area of ecotoxicology. Subcellullar distribution of metal accumulated within an organism can be used to understand metal trophic transfer within a food chain. Thus, in a final stage we examined how Cd subcellular distribution in plants with different patterns of Cd accumulation can affect assimilation of Cd by the isopod. The distribution of Cd between the four different subcellular fractions obtained by differential centrifugation revealed significant differences between the plant species. This, together with the direct assessment of isopod Cd AE from individual subcellular fractions of the leaves of the three plant species, resulted in vital information to help explain the differences observed in Cd AE by isopods fed the different type of leaves. On the basis of our results, Cd bound to heat-stable proteins (e.g. phytochelatins and methallothionein) was the least bioavailable to isopods and contributed less to the trophic transfer of Cd, while Cd bound to heat-denatured proteins was the most trophically available to the isopod. These results point to the ecological relevance of the subcellular distribution of consumer and highlight that a shift in Cd subcellular distribution in plants due to different detoxifying mechanisms may have a direct impact in the trophic transfer of Cd to the animal consumer.

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Hames, C. A. C. « The digestive system and metals in terrestrial isopods ». Thesis, University of Reading, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234697.

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Hobbins, C. St C. « Some aspects of zonation and systematics of marine isopods ». Thesis, Bangor University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.305129.

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Kennedy, Fergus. « The locomotor behaviour of peracarid crustaceans on wave-exposed sandy beaches of Chile ». Thesis, Bangor University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.263174.

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Tuck, Joanne Michelle. « Effects of spatial heterogeneity on the ecology of terrestrial isopods ». Thesis, University of East Anglia, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368185.

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Ferreira, Nuno Gonçalo de Carvalho. « The effects of chemicals in isopods : a multi-organizational evaluation ». Doctoral thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/14095.

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Doutoramento em Biologia
The global aim of this thesis was to evaluate and assess the effects of a pesticide (dimethoate) and a metal (nickel), as model chemicals, within different organization levels, starting at the detoxification pathways (enzymatic biomarkers) and energy costs associated (energy content quantification, energy consumption and CEA) along with the physiological alterations at the individual and population level (mortality), leading to a metabolomic analysis (using liquid 1H-NMR) and finally a gene expression analysis (transcriptome and RT-qPCR analysis). To better understand potential variations in response to stressors, abiotic factors were also assessed in terrestrial isopods such as temperature, soil moisture and UV radiation. The evaluation performed using biochemical biomarkers and energy related parameters showed that increases in temperature might negatively affect the organisms by generating oxidative stress. It also showed that this species is acclimated to environments with low soil moisture, and that in high moisture scenarios there was a short gap between the optimal and adverse conditions that led to increased mortality. As for UV-R, doses nowadays present have shown to induce significant negative impact on these organisms. The long-term exposure to dimethoate showed that besides the neurotoxicity resulting from acetylcholinesterase inhibition, this stressor also caused oxidative stress. This effect was observed for both concentrations used (recommended field dose application and a below EC50 value) and that its combination with different temperatures (20ºC and 25ºC) showed different response patterns. It was also observed that dimethoate’s degradation rate in soils was higher in the presence of isopods. In a similar study performed with nickel, oxidative stress was also observed. But, in the case of this stressor exposure, organisms showed a strategy where the energetic costs necessary for detoxification (biomarkers) seemed to be compensated by positive alterations in the energy related parameters. In this work we presented for the first time a metabolomic profile of terrestrial isopods exposed to stressors (dimethoate and niquel), since until the moment only a previous study was performed on a metabolomic evaluation in nonexposed isopods. In the first part of the study we identify 24 new metabolites that had not been described previously. On the second part of the study a metabolomic profile variation of abstract non-exposed organism throughout the exposure was presented and finally the metabolomic profile of organisms exposed to dimethoate and nickel. The exposure to nickel suggested alteration in growth, moult, haemocyanin and glutathione synthesis, energy pathways and in osmoregulation. As for the exposure to dimethoate alterations in osmoregulation, energy pathways, moult and neurotransmission were also suggested. In this work it was also presented the first full body transcriptome of a terrestrial isopod from the species Porcellionides pruinosus, which will complement the scarce information available for this group of organisms. This transcriptome also served as base for a RNA-Seq and a RT-qPCR analysis. The results of the RNA-Seq analysis performed in organisms exposed to nickel showed that this stressor negatively impacted at the genetic and epigenetic levels, in the trafficking, storage and elimination of metals, generates oxidative stress, inducing neurotoxicity and also affecting reproduction. These results were confirmed through RT-qPCR. As for the impact of dimethoate on these organisms it was only accessed through RT-qPCR and showed oxidative stress, an impact in neurotransmission, in epigenetic markers, DNA repair and cell cycle impairment. This study allowed the design of an Adverse Outcome Pathway draft that can be used further on for legislative purposes.
Os efeitos negativos de contaminantes de origem antropogénica que aparecem no meio ambiente têm um impacto negativo muitas vezes em organismos considerados benéficos. Dentro deste grupo de organismos podemos incluir os isópodes terrestres, detritivorous, cuja função se baseia na fragmentação de matéria vegetal, que poderão posteriormente ser facilmente colonizados por bactérias e os seus nutrientes incorporados nos solos. Para avaliar os efeitos de contaminantes em isópodes terrestres, mais concretamente na espécie Porcellionides pruinosus, foram usados como modelos o metal níquel e o pesticida dimetoato, fazendo uma abordagem em diferentes níveis organizacionais. O trabalho iniciou-se pela avaliação do impacto a nível das vias de destoxificação (biomarcadores enzimáticos) e reservas energéticas (quantificação das reservas, consumo energético e alocação da energia celular), juntamente com alterações a nível dos indivíduos e da população (mortalidade), passando por uma análise de metabolómica (usando 1H-RMN de líquidos) e finalmente uma análise da expressão génica (transcriptoma e RT-qPCR). De forma a melhor entender as variações que podem ocorrer oriundas de variações de fatores abióticos, foi também realizado um estudo sob os efeitos da variação de temperatura, humidade do solo e radiação UV em isópodes terrestres. A avaliação feita a nível dos biomarcadores bioquímicos, quantificação das reservas e parâmetros energéticos demonstrou que o aumento da temperatura iria afectar negativamente os organismos devido ao stress oxidativo gerado. Tendo em conta que esta espécie está aclimatada a ambientes com solos com humidades baixas, a exposição a solos com humidades superiores mostrou a existência de um pequeno intervalo entre o que são consideradas condições óptimas e condições bastante adversas, sendo aí verifica uma elevada mortalidade. Os efeitos da radiação UV demonstraram que as doses que actualmente chegam à superfície do planeta constituem uma ameaça para os isópodes terrestres. A avaliação feita à toxicidade do dimetoato em biomarcadores bioquímicos, reservas e parâmetros energéticos, demonstrou que além da toxicidade já esperada (inibição da enzima acetilcolinesterase), este stressor induz igualmente stress oxidativo. Este efeito foi observado para ambas as concentrações usadas (dose recomendada de aplicação em campo e dose próxima do EC50) e que a sua combinação com diferentes temperaturas (20ºC resumo e 25ºC) dava origem a diferentes padrões de resposta. Também foi observado que a taxa de degradação do dimetoato era superior em solos com a presença de isópodes. Num estudo semelhante ao anterior, realizado com níquel, foi observada toxicidade induzida por stress oxidativo. No entanto os organismos expostos a este stressor apresentam uma estratégia em que os custos energéticos associados à destoxificação (biomarcadores bioquímicos) parecem ser compensados com alterações positivas a nível dos parâmetros energéticos. Neste trabalho é apresentado pela primeira vez o perfil metabolómico de isópodes terrestres expostos a dimetoato e níquel, sendo que até à data apenas um estudo tinha apresentado o perfil metabólico de isópodes em situação de homeostasia. Na primeira parte do estudo é apresentado o perfil metabólico que identifica 24 novos metabolitos que ainda não tinham sido descritos anteriormente. Numa segunda parte é apresentada uma variação do perfil de organismos não expostos ao longo do ensaio e finalmente são apresentadas as variações metabólicas em organismos expostos a dimetoato e a níquel. Os resultados mostraram que ambos os stressores causaram alterações que eram dependentes da concentração e do tempo. Quando expostos a níquel os organismos evidenciam alterações ao nível do crescimento, muda e síntese de hemocianina e glutationas, alterações ao nível das vias energéticas e na osmorregulação. Em relação aos efeitos da exposição a dimetoato, foram observadas alterações a nível da osmorregulação, das vias energéticas e na muda, mas também ao nível da neurotransmissão. Neste trabalho é apresentado pela primeira vez um transcriptoma completo de um isópode terrestre, da espécie Porcellionides pruinosus. Este transcriptoma veio complementar a atual, mas parca, informação disponível sobre este grupo de organismos. Tendo como base o transcriptoma, foi posteriormente realizada uma análise de RNA-Seq e de RT-qPCR. A análise de RNA-Seq foi realizada apenas em organismos expostos a níquel e mostrou que este stressor tem um impacto ao nível genético e epigenético, no transporte, acumulação e eliminação de metais, gera stress oxidativo, neurotoxicidade e afecta também a reprodução. Estes resultados foram confirmados pela análise feita através de RT-qPCR. Em relação aos efeitos de dimetoato nestes organismos a nível genómico, a sua avaliação foi apenas realizada através de RT-qPCR. Foi observado que este stressor gera stress oxidativo, neurotoxicidade, tem um impacto em marcadores epigenéticos, na reparação de ADN e provoca alterações a nível da divisão celular. Este estudo permitiu a realização de uma “Adverse Outcome Pathway” (AOP) que poderá ser usada mais tarde para fins legislativos.

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Gouws, Gavin. « The biogeography, systematics and conservation of Phreatoicidean isopods in South Africa ». Thesis, Stellenbosch : University of Stellenbosch, 2004. http://hdl.handle.net/10019.1/16052.

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Dissertation (PhD)--University of Stellenbosch, 2004.
ENGLISH ABSTRACT: Historically, isopods of the suborder Phreatoicidea were thought to be represented in southern Africa by four species belonging to the endemic genus Mesamphisopus. This taxonomy was based on poor collections and the extent of variation among and within populations were poorly understood. In the present study, intensive sampling was undertaken to determine the diversity, distribution and biogeography of phreatoicidean isopods within South Africa. Analyses of allozyme data and mitochondrial DNA sequences (from the 12S rRNA and protein-coding COI genes) were used to examine differentiation among populations, extricate species boundaries (in combination with morphometric and morphological data) and to elucidate the evolutionary relationships among taxa. Additionally, conservation units were identified among the sampled populations and conservation threats highlighted. First, genetic and morphometric differentiation was examined among populations identified morphologically as M. capensis. Collection localities spanned two mountainous regions in the Western Cape and these were separated by a coastal plain remnant. Five morphometrically and genetically distinct species were identified. These taxa are also geographically partitioned in two regions, which were regarded as Evolutionarily Significant Units. Differentiation among populations of the two regions, and similar patterns in other taxa, was attributed to Cenozoic sea-level fluctuations. Second, populations, variably assigned to M. abbreviatus or M. depressus, were examined to determine whether they were conspecific. A large geographic area was sampled to account for intraspecific differentiation. Limited morphometric discrepancies were observed, with individual populations being either similar to the M. abbreviatus or the M. depressus syntypes. Genetic support for the recognition of a cryptic species complex among the sampled populations was equivocal. Substantial genetic differentiation and a lack of gene flow were observed among all populations. Clear patterns of isolation by distance were not detected, and genetic structure appeared to be unrelated to geography or drainage systems. The mosaic pattern of relatedness among populations was best explained by stochastic demographic processes, such as extinction-recolonization events or population bottlenecks.Thirdly, detailed taxonomic descriptions and illustrations of six new species, identified genetically and morphometrically among the populations included in the above analyses, were provided. These species were largely distinguished from each other, and the four original species, using a combination of setation, mouthpart, pleopod and uropod features. Lastly, phylogenetic relationships among all ten recognized Mesamphisopus species, and an additional unresolved group of populations, were examined. MtDNA data partitions and a recoded allele frequency matrix were analysed independently and in combination. Topologies indicated unrecognized species-diversity within an unresolved group of populations. Evolutionary relationships, the identification of six biogeographic centres, and the dating of divergences using a relaxed Bayesian clock suggested that differentiation and speciation within Mesamphisopus was largely allopatric or vicariant and driven by Mesozoic sea-level and climate change. Chance long distance dispersal events would, in turn, explain spurious phylogenetic relationships and distributions. This study contributes significantly to the understanding of the diversity and the conservation of the little-studied southern African freshwater invertebrates. Moreover, this study is the first to investigate genetic and morphometric differentiation, and phylogenetic relationships, below the generic level within the Phreatoicidea; thus establishing a methodological and theoretical framework for species delineation and the accurate determination of biodiversity within individual phreatoicidean genera.
AFRIKAANSE OPSOMMING: Isopoda van die suborder Phreatoicidea was histories in suidelike Afrika verteenwoordig deur vier spesies wat almal aan die endemiese genus Mesamphisopus behoort. Hierdie taksonomie is op ’n beperkte hoeveelheid versamelings gebaseer en die omvang van variasie tussen (en binne) bevolkings was swak verstaan. In die huidige studie is ekstensiewe versameling onderneem om die verspreiding, diversiteit asook biogeografie van dié Isopoda in Suid Afrika te bepaal. Analises van allosiem data en mitokondriale DNS volgorderbepalings (van die 12S rRNS en die proteïenkoderende COI geen) was gebruik om differensiasie tussen bevolkings te ondersoek, om (in kombinasie met morfometriese en morfologiese data) spesiesgrense te bepaal asook om die evolusionêre-verwantskappe tussen taksa te definieer. Benewens word bewaringseenhede binne die studie-bevolkings geïndentifiseer en moontlike bedreigings uitgelig. Eerstens is genetiese en morfometriese differensiasie tussen bevolkings, wat as M. capensis geïdentifiseer is, ondersoek. Versamelingslokaliteite was versprei oor twee bergagtige streke in die Weskaap wat geskei word deur ’n voormalige kusvlakte. Vyf morfometries- en geneties-afsonderlike spesies is geïdentifiseer. Dié taksa was geografies geskei tot die twee streke, wat elk as ’n Evolusionêre Beduidende Eenheid (ESU) gesien kan word. Differensiasie tussen populasies van die twee streke en vergelykbare patrone binne ander taksa word aan Cenosoïese seevlak veranderings toegeskryf. Tweedens is bevolkings wat as M. abbreviatus óf as M. depressus geïdentifiseer kan word ondersoek om te bepaal of hulle konspesifiek is. Bevolkings is oor ’n groot geografiese gebied versamel om intraspesifieke variasie in aanmerking te neem. Beperkte morfometriese verskille is waargeneem – enkel bevolkings was morfometries identies aan of die M. abbreviatus of die M. depressus sintipes. Genetiese getuienis vir die herkenning van ’n kriptiese spesieskompleks was dubbelsinnig. Bevolkings is gekenmerk deur merkbare genetiese differensiasie en die afwesigheid van geenvloei. Duidelike bewys van isolasie-metafstand was nie waargeneem nie en genetiese struktuur was nie verwant aan geografiese ligging of riviersisteme nie. Die mosaïese patroon van verwantskappe is moontlik teweeg gebring deur stogastiese demografiese prosesse soos uitsterwing en hervestiging of deur afnames in bevolkingsgrootte.Derdens is omvattende taksnomiese beskrywings en illustrasies van ses nuwe spesies wat deur bogenoemde analises geneties en morfometries uitgelig was, verskaf. Dié spesies is van mekaar, asook die ander vier spesies onderskeibaar deur ’n kombinasie van setasie-, monddeel-, pleiopoot- en uropooteienskappe. Laastens is die filogenetiese verwantskappe tussen al tien herkende Mesamphisopus-spesies en ’n groep bevolkings waarvan verhoudings onseker was, ondersoek. MtDNS datastelle en ’n hergekodeerde alleelfrekwensie matriks is afsonderlike en in kombinasie geanaliseer. Topologië het onherkende spesies-vlak diversiteit binne die bogenoemde groep bevolkings aangedui. Evolusionêre verwantskappe, die herkenning van ses biogeografiese gebiede, en die bepaling van tye van divergensie (d.m.v. ’n ontspanne Bayesiaanse molekulêre klok) het aangetoon dat spesiasie binne Mesamphisopus grootliks allopatries was en deur Mesosoïese seevlak- en klimaatsveranderings teweeg gebring is. Toevallige lang-aftstand verspreiding kon dan eienaardige filogenetiese verhoudings en verspreidings verklaar. Dié studie lewer ’n wesenlike bydrae tot die kennis van die diversiteit en tot die bewaring van die onbestudeerde Suid Afrikaanse varswater ongewerweldes. Daarenbowe, is hierdie studie die eerste om genetiese en morfometriese differensiasie benede die genusvlak binne die Phreatoicidea te ondersoek; sodoende word die metodologiese en teoretiese raamwerk vir die herkenning van spesies en die akkurate beskrywing van diversiteit binne afsonderlike genera van die Phreatoicidea geskep.

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Judd, Simon L. « Terrestrial isopods (Crustacea : Oniscidea) and biogeographical patterns from South-Western Australia ». Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2004. https://ro.ecu.edu.au/theses/1613.

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This thesis examines terrestrial isopod (Crustacea: Oniscidea) diversity and biogeography from south-western Australia, a region already recognised for the exceptional high biodiversity and concentrations of endemic species. A taxonomic investigation of isopods in the Western Australian Museum and material collected systematically as part of this study revealed seventy taxa, sixty of which were considered native species. The thesis provides a comprehensive review of regional taxonomic history and includes a key, complete with a set of forty characters states and taxa, illustrated by a number of photographic plates that are designed for use by specialists and non-specialists alike. Prior to this study all the region's indigenous terrestrial isopods were poorly described and, while many taxa are still to be resolved at the species level, it appears at least 35 species are new to science. The distributions of indigenous taxa form some clear and consistent biogeographical patterns. Distributions of taxa are influenced by steep rainfall gradients, the seasonality of rainfall and by biophysical characteristics of the landscape including, localised landforms and differing microhabitat utilisation. The region is one of high diversity, with both widely distributed species and highly localised endemics. Two areas, the Perth region of the Swan Coastal Plain and the tall, wet southern forests, are particularly species rich. Beta diversity is also high. This reflects a heterogeneous landscape with profound differences in microhabitat availability, differences often due to recent exogenous disturbance. The construction of a biogeographic model showed a major fauna/ break, which created northern and southern bioregions to which 68% of the taxa were endemic. This biogeographical boundary is significant in that it had not been recognised in any previous biogeographical schemes. Data derived from the analysis of soil, leaf litter and log microhabitat samples show that the existence of terrestrial isopods in south-western Australia is intractably related to organic matter. The geographical range of species is often best explained by the types of microhabitat utilised and their degree of moisture dependency. The wetter forests of the region contain relictual short range endemics reliant upon surface organic matter, particularly leaf litter. Moisture is clearly a limiting factor in the distribution of all species. The five most common genera can be differentiated by their dependence upon different moisture regimes in a range of microhabitat types. The spatial and temporal continuity of different types of organic matter in forested landscapes is considered critical to the conservation of the group in south-Western Australia. Land management practices, such as logging and burning, which influence the nature and distribution of organic matter, are likely to induce profound changes in terrestrial isopod communities. Regular and broadscale prescription burning and the increasing scarcity of large and decayed logs are considered to be a primary threat to their conservation status. Hypotheses involving the historical role of surface organic matter are developed to explain the speciation patterns of the group in the region. In order to test these models, and to provide an urgently needed assessment of the conservation status of relictual forest invertebrates, clear taxonomic priorities are recommended.

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Briggs, Sarah A. « Distribution of Parasitic Isopods on Caridean Shrimp in South Florida Seagrass Beds ». NSUWorks, 2013. http://nsuworks.nova.edu/occ_stuetd/181.

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Caridean shrimp are a prominent element of seagrass faunal communities and play an important role in the energy transfer between trophic levels. They are a food source for other organisms and play an integral role in the ecosystem by feeding on algae and assisting with the breakdown of organic matter. Carideans are also fundamental to the marine fishery industry in that they are a food source for potentially valuable juvenile commercial fish. Ectoparasitic isopods (Cymothoida: Bopyridae) that infest caridean shrimps decrease the energy level of the shrimp, resulting in slower reaction time, greater predation rate, slower growth rate, and/or reduced egg production. However, in South Florida, little is known about the distributions and effects of parasitism among caridean shrimp in seagrass habitats. This research investigates the relationship of caridean shrimps and ectoparasitic isopods throughout several marine and brackish basins of coastal South Florida ranging from Lostmans River on the lower southwest mangrove coast through Florida Bay and Biscayne Bay. Samples were collected at the end of the wet season in 2010 and the dry season in 2011 using a 1-m2 throw-trap. Relations among isopods, carideans and environment were determined based on a series of biotic (host preference and availability) and abiotic (salinity, temperature, turbidity, water depth) factors. Bopyrid isopods were most abundant in Manatee Bay and Barnes Sound adjacent to the C-111 canal located in southern Biscayne Bay region and predominantly associated with Hippolyte spp. Logistical regression revealed that the likelihood of parasite presence is associated with higher temperatures, lower salinity, increasing depth, less seagrass coverage and greater macroalgae coverage. The results suggest that increased stressors in an environment, such as anthropogenic runoff, may also negatively impact host resistance to parasitism.

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au, andrew@wrlc com, et Andrew Charles Winzer. « The biology and prevalence of Cirolana hesperia and their effect on the Western Rocklobster Fishery ». Murdoch University, 2007. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20090727.115745.

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The current study had two overriding and inter-related aims. The first was to describe the biology of C. hesperia the dominant scavenging subtidal cirolanid found in temperate waters off the Perth metropolitan coastline and thereby extend our knowledge and test several hypotheses regarding the biology of scavenging crustaceans in general. The second was to use the biological information generated to develop fishing practices that reduce the amount of bait used by trap based fisheries without reducing the overall catch. Fulfilling the latter aim has the potential to greatly reduce some of the deleterious effects of fishing practices around the world. A survey was designed to determine whether the anecdotal evidence that commercial rocklobster fishers believe sea lice have a negative impact on the ratio of bait used to rocklobster landed was widespread across the fishery and, if so, whether they associated particular factors with increases or decreases in lice numbers. The response rate of over 40% was high for a survey of this type and had similar return rates across all zones of the fishery. Such a high return rate, in addition to the responses confirms that commercial fishers, regardless of zone, consider that sea lice have adverse effects on the ratio of bait used to rocklobster landed. The findings of the survey allowed the following conclusions to be drawn and hypotheses developed. Commercial fishers believe particular temporal and spatial factors are associated with increased numbers of sea lice predating on rocklobster baits. For example, fishing in depth ranges of 20 - 30 fathoms (40 60 metres) and greater, fishing on a sand bottom, fishing during the months of November, December, March and April, fishing during the full and new moons and lastly during periods of weak current and high water temperature were all felt to increase the number of sea lice scavenging on baits. Laboratory growth trials demonstrated significant differences in the mean body lengths of starved and fed manca and adult C. hesperia after three and seven months, respectively. Despite these findings, starved adult C. hesperia continued to moult and grow after approximately 300 days of fasting. The relatively short period of time before differences in starved and fed manca C. hesperia growth parameters arose is probably due to early life stages of cirolanids being more reliant on regular food sources than their adult counterparts. An increase in water temperature from 16 ºC to 24 ºC resulted in no significant increase in mean body length of manca C. hesperia. However, the mean inter-moult period of fed manca housed at 24 ºC was significantly lower (25-50%) than both the fed treatment group housed at 16 ºC and the starved treatment group within the first two months of the trial. This reduction in mean inter-moult period is indicative of an animal which is growing quickly as a result of increased metabolic rate albeit at reduced increments. The 24 hour activity rhythms of C. hesperia in shallow waters in the metropolitan zone of the Western Rocklobster Fishery were determined in order to identify those factors which modulate the emergence and/or swimming activity of this dominant scavenger. It was concluded that the presence of a circadian rhythm of spontaneous nocturnal activity induced by the end of the diurnal period of photo-inhibition,regardless of tidal regime or lunar cycle, is evident in adult C. hesperia. In contrast, circa-tidal rhythms of emergence centered around spring tides were found to exist in juvenile C. hesperia with similar mean numbers trapped across all sampling times (see Chapter 3, tables 3.4-3.8) with the exception of high water spring tides (HWS), which resulted in significantly greater mean numbers. It was concluded that mature cirolanids found off the Western Australian coastline adopt a strictly nocturnal and facultative necrophage mode of existence despite carrion generally being regarded as a much less crucial food resource in relatively shallow, productive, inshore waters. However, juvenile cirolanids found off the Western Australian coastline were recognised as relying on a more opportunistic scavenger mode of existence being active during both day and night. This perpetual foraging strategy employed in cirolanids at manca and juvenile stages is possibly due to the lack of the well developed chemosensory and or olfactory capabilities found in their adult stages. In addition to this reduced foraging efficiency, a smaller gut size combined with higher metabolic rates and lower assimilation efficiencies ensures their ongoing search for sustenance. Analyses of the number of C. hesperia collected during three years of trapping in C zone of the Western Rocklobster Fishery clearly demonstrated that the numbers of cirolanids caught in rocklobster pots were significantly affected by bottom type, moon phase and depth. With respect to bottom type, the greatest numbers of C. hesperia were trapped in rocklobster pots deployed on weed/rock and sand bottoms while significantly lower numbers of C. hesperia were trapped on rock or weed bottoms. In regards to moon phase, rocklobster pots deployed during the new and last quarter of the moon phase trapped significantly greater numbers of both C. hesperia and the Western Rocklobster, P. cygnus than those deployed during the full and first quarter phases. Rocklobster pots containing lice traps deployed in depths ranging from 10-19 and 20-29 fathoms (20-39 and 40-59 metres respectively) caught significantly greater numbers of C. hesperia and P. cygnus than pots deployed in the 1-19 metre depth range. Lastly, the catchability of both C. hesperia and P. cygnus was greatest when either Australian salmon or blue mackerel was deployed in pots indicating these scavengers do exercise a degree of selectivity with respect to particular bait types. Whilst ovigerous C. hesperia were present in each month of the year, peaks in their abundance and/or catchability occurred at the height of summer (January to March). These peaks in mpm, i.e. morphological parturial moult stage, C. hesperia were then followed by corresponding peaks in recruitment from April to June. I hypothesise that peaks in the reproductive intensity of C. hesperia can be attributed to peaks in water temperature and also the seasonal influx of carrion due to both recreational and commercial charter fishing and the commencement of the rocklobster season all occurring predominately within a similar time frame, i.e. the warmer months. The current study has clearly demonstrated that a plethora of factors attract high numbers of both C. hesperia and P. cygnus. Thus, it is apparent that those practices employed by commercial fishers to land the greatest number of P. cygnus will also attract significant numbers of C. hesperia to rocklobster baits. Irrespective of key factors driving C. hesperia abundance, the high market price received for P. cygnus in conjunction with the relatively low price payed for bait, ensures fishers will continue to deploy rocklobster pots in the manner which maximises their landings. Thus for a reduction in bait usage to offer significant economic savings to the industry, different methods of bait deployment that do not result in a decrease in the catch of P. cygnus must be developed. A series of baitsaver trials were conducted in order to determine whether baitsavers deployed containing reduced quantities of bait would catch the same numbers of rocklobster as conventional pots using the typical amounts of bait employed in the fishery. During the start of the season the majority of fishers concentrate their efforts in shallow waters and employ predominantly one day soaks as they target rocklobster migrating from the shallows to offshore habitats (whites phase November to February). In the later parts of the season (reds phase March to June) fishing effort becomes less concentrated as some fishers continue to fish the inshore grounds whilst others move out into deeper waters. The season long trial demonstrated that packing large quantities of bait in both baitboxes in the pot (traditional method) caught significantly more rocklobster than pots using a baitsaver in one bait box while the other bait box was packed in traditional fashion (combined method) during the first two months of the whites phase. However, during the remainder of the season there was no significant difference in catches between the two methods. Thus, the season-long trial found that the use of traditional methods of bait deployment in the first two months of the season in conjunction with the combined method of bait deployment from January until the end of the commercial season has the potential to save inshore and offshore based fishers $34,000 and $36,000 each year.

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Geniez, Sandrine. « Investigation of Wolbachia symbiosis in isopods and filarial nematodes by genomic and interactome studies ». Thesis, Poitiers, 2013. http://www.theses.fr/2013POIT2277/document.

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Les Wolbachia sont des alpha-proteobactéries présentes chez de nombreux arthropodes et nématodes filaires. Ces bactéries héritées maternellement induisent chez leurs hôtes des phénotypes allant du parasitisme au mutualisme, avec le long de ce continuum des phénotypes tels que la féminisation (F), l'incompatibilité cytoplasmique (IC) ou la mort des mâles. Wolbachia est ainsi un modèle particulièrement intéressant pour étudier les différents types de relations symbiotiques.Chez Brugia malayi, comme pour les autres nématodes filaires, Wolbachia vit en symbiose obligatoire avec son hôte. L'élimination de la bactérie par des traitements antibiotiques entraîne une perte de fertilité voire la mort du nématode. Chez l'isopode terrestre Armadillidium vulgare, Wolbachia induit la féminisation des mâles génétiques en femelles fonctionnelles entraînant des biais de sex-ratio vers les femelles dans la descendance.Pour comprendre les mécanismes impliqués dans ces deux symbioses, nous avons mis au point une nouvelle méthode de capture pour isoler l'ADN de Wolbachia et séquencer 8 souches de Wolbachia d'isopodes (F et IC). Une étude de génomique comparative a permis d'établir un premier pan-génome des bactéries du genre Wolbachia et d'identifier 2, 5 et 3 gènes présents seulement chez les souches mutualistes, féminisantes ou induisant la mort des mâles. L'expression des gènes potentiellement impliqués dans la féminisation ou le mutualisme a été étudiée au cours du développement de l'hôte. L'étude de l'interactome protéique bactérie-hôte a ensuite été initiée en utilisant comme appât des protéines bactériennes à domaines eucaryotes en vue d'identifier les cibles de Wolbachia chez l'hôte
Bacteria of the genus Wolbachia are gram-negative alpha-proteobacteria present in many arthropods and filarial nematodes. These obligate intracellular bacteria are maternally inherited and induce a large number of phenotypes across the symbiosis continuum from mutualism to parasitism, including feminization (F), cytoplasmic incompatibility (CI) or male killing. Studying Wolbachia symbioses is therefore of particular interest in the investigation of symbiotic relationships.In Brugia malayi and other filarial nematodes, they are obligate leading to a loss of worm fertility, and eventual death upon their depletion with antibiotic. In arthropods, they rather are parasitic. In the isopod crustacean Armadillidium vulgare they cause feminization when present: genetic males develop as functional female leading to female biased sex-ratio progenies.In order to understand the molecular mechanisms of these two symbioses, we set up a new capture procedure to catch Wolbachia DNA and performed whole-genome sequencing on 8 Wolbachia strains, symbionts of isopods (F & CI). Comparative genomics led to the establishment of the Wolbachia pan-genome as well as the identification of phenotype related gene patterns. We identified 2, 5 and 3 genes that are only found in mutualist, feminizing and male killing strains, respectively. Expression of genes potentially involved in feminization and mutualism were also analyzed throughout host post-embryonic development. Host-symbiont interactome approach was then initiated by protein-protein interaction studies using bacterial proteins with eukaryote like motifs as bait in order to identify Wolbachia host targets involved in symbiosis

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Mifsud, Daniel Vincent. « The genetic basis of speciation in the Jaera albifrons species group of intertidal isopods ». Thesis, University of Aberdeen, 2011. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=166168.

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The Jaera albifrons species group of intertidal isopods is characterised by strong sexual isolation mediated by female discrimination against heterospecific male tactile-stimulatory courtship behaviour. This is the first study to examine the genetic basis of traits involved in tactile mediated sexual isolation. To determine the genetic architecture of male secondary sexual characters (species-specific hair traits carried on the legs of males and a carpus leg-segment shape difference) associated with sexual isolation, experimental hybrid populations of J. albifrons and J. ischiosetosa were used to construct AFLP-based genetic linkage maps. A number of chromosomal differences (Robertsonian fusions) between the parental species were shown to be associated with reduced hybrid fertility. A quantitative trait locus (QTL) mapping study revealed that the number of hairs and carpus shape have a complex genetic basis, involving a number of QTL showing dominance, epistasis and possible pleiotropic effects. These QTL mapped largely to putative regions of restricted recombination, especially chromosomal rearrangements. The qualitative difference, however, was shown to be controlled by a single (or several closely linked ) QTL that did not map to a region of restricted recombination. These findings suggest that introgressive hybridisation played an important role in speciation in the J. albifrons species group and that chromosomal rearrangements allowed incipient species to persist in the face of ongoing gene flow. The extensive sharing of a single 16S rDNA mitochondrial haplotype supports the assertion that gene flow has been important. The reinforcement of premating isolating by natural selection against costly hybridisation is suggested as the mechanism of speciation between these species. The complete dominance of the J. albifrons allele at the QTL controlling the qualitative difference between the species supports this model of speciation.

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Moss, Anna. « Effects of sward structure and climate change on the ecology and behaviour of grassland isopods ». Thesis, University of East Anglia, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.443184.

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Martinez, Melissa Gaste [UNESP]. « Histórico alimentar das serpentes Crotalus durissus terrificus pela análise do isótopo do carbona-13(δ13C) no guizo ». Universidade Estadual Paulista (UNESP), 2009. http://hdl.handle.net/11449/89929.

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Made available in DSpace on 2014-06-11T19:24:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-11-12Bitstream added on 2014-06-13T19:51:38Z : No. of bitstreams: 1 martinez_mg_me_botfm.pdf: 823731 bytes, checksum: 14318dd910b1fde35bc83924fa448a33 (MD5)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Universidade Estadual Paulista (UNESP)
As serpentes Crotalus durissus terrificus possuem cabeça triangular, olhos pequenos com pupila em fenda, fosseta loreal e guizo na cauda. O veneno é uma mistura complexa constituído de cátions metálicos, enzimas, peptídeos e toxinas. Os acidentes em seres humanos e em animais no Estado de São Paulo, Brasil estão em ascensão. Apesar da devastação ambiental, o número de serpentes que são capturadas e doadas aos Institutos de pesquisa também está aumentando. A questão é: Como estes animais conseguiram se adaptar e procriar apesar destas novas condições ambientais adversas? Para responder esta questão avaliou-se o nível de Carbono 13 (13C), por meio de técnica de espectrometria de massa, nos segmentos dos guizos de serpentes Crotalus durissus terrificus (Cdt) adultas e filhotes, bem como no alimento oferecido. Esta pesquisa foi baseada no conhecimento de que as plantas existentes na terra apresentam rotas bioquímicas diversas, absorvendo isótopos estáveis nas suas moléculas principalmente o Carbono (12C, 13C), o Hidrogênio (1H, 2H), o Oxigênio (16O, 17O, 18O), o Nitrogênio (14N, 15N) e o Enxofre (32S, 33S, 34S, 36S). Durante a síntese dos açúcares, quando o primeiro composto orgânico sintetizado for açúcar contendo três átomos de carbono, estas são denominadas de plantas do ciclo fotossintético C3. Quando os primeiros açúcares formados apresentam quatro átomos de carbono, estas são denominadas de plantas do ciclo fotossintético C4. No grupo C3 encontram-se aproximadamente 86% das espécies vegetais, tais como, as madeiras de lei, as leguminosas e as árvores frutíferas. No grupo C4, destacam-se principalmente as gramíneas, milho e cana-de-açúcar. A análise dos resultados em seu conjunto permitiu tecer as seguintes considerações: as serpentes Crotalus durissus terrificus se alimentam de animais provenientes tanto do ambiente C3 quanto...
The Crotalus durissus terrificus serpents possess triangular head, small eyes with pupil in crack, little loreal pit and rattle in its tail. The poison is a complex mixture constituted of metallic cations, enzymes, peptides and toxins. The accidents with human beings and animals in Sao Paulo State, Brazil are in ascension. Although the environment devastation, the number of serpents captured and donated to the research institutes is also increasing. The question is: How these animals had managed to adapt themselves and to procreate in spite of these new adverse environmental conditions? To answer this question it was evaluated the Carbon 13 level (13C), through of mass spectrometry technique, in the segments of the rattles of adults and nestlings Crotalus durissus terrificus serpents (Cdt), as well as in the offered food. This research was based on the knowledge of that the existing plants in the world present diverse biochemists routes, absorbing stables isotopes in its molecules mainly the Carbon (12C, 13C), the Hydrogen (1H, 2H), the Oxygen (16O, 17O, 18O), the Nitrogen (14N, 15N) and the Sulphur (32S, 33S, 34S, 36S). During the sugars synthesis, when the first synthesized organic composition was sugar contained three carbon atoms, these are called of plants of the C3 photosynthetic cycle. When the first formed sugars present four carbon atoms, these are called of plants of the C4 photosynthetic cycle. About 86% of the vegetal species are found in the C3 group, such as, the hardwoods, the vegetables species and fruitful trees. In the C4 group, the grass species, maize and sugar cane are mainly distinguished. The analysis of the results allowed the following considerations: the Crotalus durissus terrificus serpents eat animals proceeding from the C3 and C4 ambient; the complete turnover tax of the nestlings born in captivity until reaching the balance level varied between... (Complete abstract click electronic access below)

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Rocha, Mauricio Martins da. « Revisão e análise filogenética de Armitermes Wasmann, 1897 (Isoptera,Termitidae, Nasutitermitinae) ». Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/41/41133/tde-08022011-192936/.

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O presente trabalho trata da revisão taxonômica e análise filogenética do gênero Armitermes Wasman, 1897 (Termitidae, Nasutitermitinae), que até esta revisão contava com 12 espécies: A. armiger, A. cerradoensis, A. euamignathus, A. gnomus, A grandidens, A. holmgreni, A. lane, A. manni, A. minutus, A. peruanus, A. projectidens e A. teevani, ocorrendo em toda Região Neotropical. Nesse trabalho, além da proposta de quatro espécies novas e duas sinonímias (A. cerradoensis com A. euamignathus e A. projectidens com A. manni), também se realizou uma análise filogenética e o resultado corrobora a criação de quatro novos gêneros, propostos com base no estudo da morfologia. Todos os soldados foram descritos e ilustrados, além das mandíbulas e tubo digestivo do operário e da casta do alado, quando disponível. Também foram incluídas chaves dicotômicas, baseadas na casta do soldado, para identificação das espécies dos gêneros propostos, além de mapas com a distribuição geográfica das espécies.
The present work deals with the taxonomic revision of the genus Armitermes Wasman, 1897 (Termitidae, Nasutitermitinae), which counts 12 species at the moment: A. armiger, A. cerradoensis, A. euamignathus, A. gnomus, A. grandidens, A. holmgreni, A. lanei, A. manni, A. minutus, A. peruanus, A. projectidens and A. teevani, occurring in all Neotropics. In this work, besides the proposal of four new species and two new synonymies (A. cerradoensis with A. euamignathus and A. projectidens with A. manni), a phylogenetic analysis was accomplished and its results used to support the proposal of four new genera based on morphology. All soldiers were described and illustrated, the mandibles and digestive tract of the worker and the imago caste, when available. Dichotomous keys based on soldiers were also included, for identifying the species of the genera proposed, as well as maps with the geographical distribution of species.

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Odendaal, James Philander. « Histological change in the hepatopancreas of terrestrial isopods as potential biomarker of cadmium and zinc exposure ». Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/52877.

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Thesis (PhD)--Stellenbosch University, 2002.
ENGLISH ABSTRACT: Metals occur naturally in the environment but since the industrial revolution the amounts ofbioavailable metals in the environment have increased significantly. There are various anthropogenic sources of metals in the environment. In recent years there has been an increasing interest in the use of biomarkers in terrestrial invertebrates for the assessment of the potential adverse effects of chemicals in soil ecosystems. Terrestrial isopods are one of the groups that play an important role in the decomposition process as fragmentors of dead plant material in soil ecosystems. They are also known to accumulate contaminants in their bodies, especially in the hepatopancreas. Cadmium has no known biological function and is deposited in the environment through a variety of sources. Zinc on the other hand is one of the essential metals and play an important role in the normal metabolism of animals. Zinc too, is deposited in the environment through a variety of anthropogenic sources. The aim of this study was to undertake an experimental and field evaluation of the role cellular change in the hepatopancreas of terrestrial isopods can play in conjunction with other sublethal responses to contribute to the assessment of the impact of cadmium and zinc in terrestrial ecosystems. Porcel/io laevis was used as test species in the laboratory experiments in this study, to conduct sublethal toxicity tests. Cadmium- and zinc sulphate were used as the contaminants, applied separately and as mixtures. The isopods were weighed before the beginning of the exposures and every week throughout the exposure period of six weeks. At the end of the exposure period they were dissected to remove the hepatopancreas. The zinc and cadmium content of the hepatopancreases and rest of the bodies of the isopods were determined by atomic absorption spectrophotometry. Hepatopancreas samples were also prepared for histological analysis, and measurements of the Percentage Cellular Area (PCA) were made using image analysis. Specimens of Porcellionides pruinosus were collected from contaminated- and uncontaminated field sites. Hepatopancreas- and rest of the body samples of P. pruinosus were also analysed for cadmium and zinc. Histological sections of the hepatopancreas were similarly prepared and analysed, as in the laboratory experiments. Exposure to cadmium- and zinc sulphate affected the mass of P. laevis negatively in the single metal exposures. However, these two metals "neutralised" each other's effects in the mixture toxicity exposures, pointing towards an antagonistic interaction. Administered cadmium- and zinc sulphate resulted in the accumulation of cadmium and zinc in the isopods, especially in the hepatopancreas. In the mixture toxicity experiments cadmium and zinc influenced the accumulation of each other. Cadmium- and zinc sulphate, whether administered separately or as mixtures, changed the structure of the hepatopancreas and this was quantitatively shown through PCA measurements. PCA of the hepatopancreas of terrestrial isopods was shown to be a good general biomarker of exposure and effects for cadmium as well as for zinc. It is suggested that PCA could serve as a general biomarker to predict possible impairment of growth or mass change of isopods exposed to cadmium and zinc mixtures. The findings of the field survey also suggest that PCA may be suitable to be used as a general biomarker to measure metal induced stress in woodlice from contaminated field sites.
AFRIKAANSE OPSOMMING: Metale kom natuurlik voor in die omgewing, maar sedert die industriële revolusie het die hoeveelheid bio-beskikbare metale in die omgewing betekenisvol toegeneem. Daar is verskeie antropogeniese bronne van metale in die omgewing. Die afgelope paar jaar was daar toenemende belangstelling in die gebruik van biomerkers by terrestriële invertebrate vir die assessering van potensiële negatiewe effekte van chemiese stowwe in grondekosisteme. Terrestriële Isopoda is een van die groepe wat 'n belangrike rol speel III die ontbindingsproses as fragmenteerders van dooie plantmateriaal III grondekosisteme. Hulle akkumuleer ook kontaminante in hul liggame, veral in die hepatopankreas. Kadmium het geen biologiese funksie nie, en word vrygestel in die omgewing deur verskeie bronne. Sink, aan die ander kant, is een van die essensiële metale en speel 'n belangrike rol in die metabolisme van diere. Sink word ook in die omgewing vrygestel deur 'n verskeidenheid antropogeniese bronne. Die doel van die studie was om deur eksperimentele en veldondersoek die rol van sellulêre veranderinge in die hepatopankreas van terrestriële Isopoda in samehang met ander subietale response te evalueer om by te dra tot die assessering van die impak van kadmium en sink op terrestriële ekosisteme. Porcellio laevis is as toets-spesie in die laboratorium eksperimente gebruik om subietale toksisiteitstoetse mee uit te voer. Kadmium- en sinksulfaat is as kontaminante gebruik, en is apart en gemeng toegedien. Die houtluise is geweeg voor die begin van die blootstellings en elke week deur die loop van die blootstellingsperiode van ses weke. Aan die einde van die blootstellingsperiode is hulle gedissekteer om die hepatopankreas te verwyder. Die sink en kadmium inhoude van die hepatopankreas en res van die liggame van die houtluise is bepaal met behulp van atoomabsorpsiespektrofotometrie. Monsters van die hepatopankreas is ook voorberei vir histologiese analise, en metings van die Persentasie Sellulêre Oppervlak (PSO) is gedoen met behulp van beeldanalise. Eksemplare van Porcellionides pruinosus is versamel van 'n gekontamineerde- en 'n ongekontamineerde gebied. Monster van die hepatopankreas en res van die liggaam van P. pruinosus is ook geanaliseer vir kadmium en sink. Histologiese sneë van die hepatopankreas was ook voorberei en geanaliseer, soos in die laboratorium eksperimente. Blootstelling aan kadmium- en sinksulfaat het die massa van P. laevis negatief beïnvloed in die enkelmetaal-eksperimente. Hierdie twee metale het egter mekaar se effekte in die mengseltoksisiteitstoetse "geneutraliseer". Dit dui op 'n antagonistiese interaksie. Toegediende kadmium- en sinksulfaat het gelei tot die akkumulasie van kadmium en sink in the houtluise, veral in die hepatopankreas. In die mengseltoksisiteitstoetse het kadmium en sink mekaar se akkumulasie beïnvloed. Kadmium- en sinksulfaat, apart of as mengsels toegedien, het die struktuur van die hepatopankreas verander, en dit is kwantitatief aangetoon deur die PSO metings. PSO van die hepatopankreas van houtluise is 'n bruikbare algemene biomerker van blootstelling en effek vir kadmium en sink. Dit word voorgestel dat PSO kan dien as 'n algemene biomerker om negatiewe effekte op die groei of massaverandering van houtluise te voorspel wat aan kadmium en sink mengsels blootgestel word. Die bevindinge van die veldondersoek dui daarop dat PSO gepas mag wees om gebruik te word as 'n algemene biomerker om metaal-geïnduseerde stres by houtluise vanaf 'n gekontamineerde gebied te meet.

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Dittmer, Jessica. « Diversity of endosymbiotic bacterial communities in terrestrial isopods : the role of feminizing Wolbachia and other major players ». Thesis, Poitiers, 2013. http://www.theses.fr/2013POIT2322/document.

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Les interactions isopodes terrestres-Wolbachia féminisantes constituent un excellent modèle d'étude des interactions multipartites complexes. A ce jour, trois Wolbachia féminisantes, issues d'histoires évolutives différentes, ont été identifiées chez l'hôte Armadillidium vulgare. L'objectif de cette thèse est d'avoir une vue plus complète du microbiote d'A. vulgare et de l'impact des souches de Wolbachia sur cette communauté bactérienne. Dans ce but, des approches quantitative et métagénomique ont été combinées afin de caractériser le microbiote d'A.vulgare à plusieurs niveaux d'intégration: (i) dans des populations naturelles et des lignées contrôlées de laboratoire, (ii) au sein de différents tissus hôtes et (iii) en relation avec le statut d'infection par Wolbachia. Aucun microbiote coeur n'a été mis en évidence malgré une relative homogénéité des communautés symbiotiques dans les tissus de l'hôte. De plus, les bactéries environnementales avaient un impact important sur le microbiote symbiotique. Chez les animaux infectés, Wolbachia représente la bactérie dominante et le facteur majeur de la structuration de la communauté symbiotique. Nous avons également mis en évidence la présence d'un autre constituant majeur du microbiote dans tous les tissus de l'hôte: Candidatus Hepatoplasma crinochetorum, un symbiote facultatif réputé jusque-là pour être seulement associé aux glandes digestives de l'intestin. Afin d'éclairer les interactions potentielles entre hôte et ce symbiote relativement peu connu, la séquence du génome de Ca. H. crinochetorum a été obtenue. Une analyse préliminaire des interactions fonctionnelles des voies métaboliques impliquées dans la digestion de la cellulose nous a permis d'identifier des enzymes cellulolytiques spécifiques de l'hôte et du symbiote. Cette étude ouvre de nouvelles perspectives dans l'étude de la symbiose chez les isopodes
In recent years, there has been a shift of focus in symbiosis studies, away from the traditional 'one host-one symbiont' concept towards a more holistic, community-based approach. This concept takes into account that a host is not only associated with one bacterium, but harbours and interacts with a diverse bacterial community, the microbiome. Terrestrial isopods represent an excellent model system for the understanding of complex multipartite symbioses due to their well-characterised association with feminizing Wolbachia bacteria. To date, three different feminizing Wolbachia strains have been identified in Armadillidium vulgare, presumably representing different host-symbiont co-evolutionary histories. The aim of this PhD was to get a more complete picture of the terrestrial isopod microbiome and the role of Wolbachia within the bacterial community. In order to achieve this, quantitative and metagenomic techniques were combined to characterize the microbiome of A. vulgare on multiple levels: (i) Field vs. lab populations, (ii) in different host tissues, and (iii) in relation to Wolbachia infection status, i.e. presence/absence of Wolbachia as well as infection with different Wolbachia strains. Wolbachia represented the predominant member of the bacterial community in infected individuals and was identified as an important factor influencing bacterial community structure. Apart from Wolbachia, we detected a second highly abundant bacterium: Candidatus Hepatoplasma crinochetorum, a facultative symbiont previously reported from the midgut caeca, was for the first time observed in all tested host tissues. The potential interactions of Wolbachia and Ca. H. crinochetorum constitute an interesting example for symbiont-symbiont relationships between two highly abundant members of a diverse bacterial community

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Martinez, Melissa Gaste. « Histórico alimentar das serpentes Crotalus durissus terrificus pela análise do isótopo do carbona-13(δ13C) no guizo / ». Botucatu : [s.n.], 2009. http://hdl.handle.net/11449/89929.

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Resumo: As serpentes Crotalus durissus terrificus possuem cabeça triangular, olhos pequenos com pupila em fenda, fosseta loreal e guizo na cauda. O veneno é uma mistura complexa constituído de cátions metálicos, enzimas, peptídeos e toxinas. Os acidentes em seres humanos e em animais no Estado de São Paulo, Brasil estão em ascensão. Apesar da devastação ambiental, o número de serpentes que são capturadas e doadas aos Institutos de pesquisa também está aumentando. A questão é: Como estes animais conseguiram se adaptar e procriar apesar destas novas condições ambientais adversas? Para responder esta questão avaliou-se o nível de Carbono 13 (13C), por meio de técnica de espectrometria de massa, nos segmentos dos guizos de serpentes Crotalus durissus terrificus (Cdt) adultas e filhotes, bem como no alimento oferecido. Esta pesquisa foi baseada no conhecimento de que as plantas existentes na terra apresentam rotas bioquímicas diversas, absorvendo isótopos estáveis nas suas moléculas principalmente o Carbono (12C, 13C), o Hidrogênio (1H, 2H), o Oxigênio (16O, 17O, 18O), o Nitrogênio (14N, 15N) e o Enxofre (32S, 33S, 34S, 36S). Durante a síntese dos açúcares, quando o primeiro composto orgânico sintetizado for açúcar contendo três átomos de carbono, estas são denominadas de plantas do ciclo fotossintético C3. Quando os primeiros açúcares formados apresentam quatro átomos de carbono, estas são denominadas de plantas do ciclo fotossintético C4. No grupo C3 encontram-se aproximadamente 86% das espécies vegetais, tais como, as madeiras de lei, as leguminosas e as árvores frutíferas. No grupo C4, destacam-se principalmente as gramíneas, milho e cana-de-açúcar. A análise dos resultados em seu conjunto permitiu tecer as seguintes considerações: as serpentes Crotalus durissus terrificus se alimentam de animais provenientes tanto do ambiente C3 quanto... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The Crotalus durissus terrificus serpents possess triangular head, small eyes with pupil in crack, little loreal pit and rattle in its tail. The poison is a complex mixture constituted of metallic cations, enzymes, peptides and toxins. The accidents with human beings and animals in Sao Paulo State, Brazil are in ascension. Although the environment devastation, the number of serpents captured and donated to the research institutes is also increasing. The question is: How these animals had managed to adapt themselves and to procreate in spite of these new adverse environmental conditions? To answer this question it was evaluated the Carbon 13 level (13C), through of mass spectrometry technique, in the segments of the rattles of adults and nestlings Crotalus durissus terrificus serpents (Cdt), as well as in the offered food. This research was based on the knowledge of that the existing plants in the world present diverse biochemists routes, absorbing stables isotopes in its molecules mainly the Carbon (12C, 13C), the Hydrogen (1H, 2H), the Oxygen (16O, 17O, 18O), the Nitrogen (14N, 15N) and the Sulphur (32S, 33S, 34S, 36S). During the sugars synthesis, when the first synthesized organic composition was sugar contained three carbon atoms, these are called of plants of the C3 photosynthetic cycle. When the first formed sugars present four carbon atoms, these are called of plants of the C4 photosynthetic cycle. About 86% of the vegetal species are found in the C3 group, such as, the hardwoods, the vegetables species and fruitful trees. In the C4 group, the grass species, maize and sugar cane are mainly distinguished. The analysis of the results allowed the following considerations: the Crotalus durissus terrificus serpents eat animals proceeding from the C3 and C4 ambient; the complete turnover tax of the nestlings born in captivity until reaching the balance level varied between... (Complete abstract click electronic access below)
Orientador: Benedito Barravieira
Coorientador: Carlos Ducatti
Banca: Marcelo Zacarias
Banca: Jorge Jim
Mestre

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Zimmermann, Bianca Laís. « Aspectos da relação simbiótica entre as bactérias Wolbachia (Alphaproteobacteria, Rickettsiales) e os isópodos terrestres (Crustacea, Oniscidea) ». reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2010. http://hdl.handle.net/10183/28424.

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Wolbachia é uma alfaproteobactéria que apresenta simbiose com uma variedade de artrópodos e nematoides, estando entre os mais abundantes gêneros de bactérias intracelulares já descobertos. Na região Neotropical, os estudos sobre tais bactérias e seus hospedeiros, em especial isópodos terrestres, ainda são incipientes. O presente trabalho teve como objetivos: investigar as espécies de isópodos terrestres neotropicais infectados por Wolbachia; analisar a prevalência de infecção, variação genética e relações filogenéticas das linhagens presentes nessas espécies; investigar a simbiose de Wolbachia em nematoides parasitos de tatuzinhos-de-jardim e inferir sobre as possíveis rotas de transmissão horizontal da bactéria entre os isópodos terrestres e os invertebrados que possuam associações ecológicas com os mesmos. A detecção da bactéria foi realizada através de PCRs diagnósticas, utilizando-se o gene 16S rDNA. A infecção pelo simbionte foi registrada pela primeira vez em Atlantoscia floridana e Burmoniscus meeusei. As linhagens de Wolbachia que infectam as espécies nativas de isópodos terrestres, ao contrário das introduzidas, são muito diversas e não se agrupam dentro do Oniclado. Já as sequências presentes em B. meeusei não são relacionadas a nenhuma outra linhagem presente em crustáceos, e nem mesmo fazem parte de qualquer supergrupo conhecido de Wolbachia. Pela primeira vez foi evidenciada a presença da bactéria em um nematoide da família Mermithidae, Agamermis sp., endoparasito do tatu-bola Armadillidium vulgare. Uma vez que as sequências do parasito e do hospedeiro são idênticas, é possível que um evento de transmissão horizontal tenha ocorrido entre ambos. Por fim, a presença de Wolbachia foi examinada em espécies que possuiam relações ecológicas com os isópodos terrestres (predadores, parasitos, foréticos e animais que vivem sob as mesmas condições ecológicas). Entre as espécies associadas, a infecção foi registrada apenas no nematoide parasito e nos ácaros foréticos. Enquanto as linhagens do isópodo hospedeiro e do nematoide se mostraram muito similares, àquelas dos ácaros foréticos não apresentaram relação filogenética com as de seus forontes Balloniscus glaber. Interessantemente, as sequências presentes nos ácaros são proximamente relacionadas com aquelas de B. meeusei, embora mais estudos sejam necessários para esclarecer tal achado.
Wolbachia is a genus of alfaproteobacteria whose members live in symbiosis with a variety of arthropods and nematodes. It is among the richest genera of intracellular bacteria discovered to date. In the Neotropical region, studies on these bacteria and their hosts, especially terrestrial isopods, are still in the initial stages. The objectives of the present study were: to investigate the species of Neotropical terrestrial isopods infected by Wolbachia; to analyze the prevalence of infection, genetic variation, and phylogenetic relationships of the lineages present in these isopod species; to investigate the symbiosis of Wolbachia in parasitic nematodes of pillbugs; and to provide information to support inferences about the possible routes of horizontal transmission of the bacteria between the terrestrial isopods and the invertebrates that are ecologically associated with them. The bacteria were detected by means of diagnostic PCR’s, using the 16S rDNA gene. Infection by this symbiont was recorded for the first time in Atlantoscia floridana and Burmoniscus meeusei. The lineages of Wolbachia that infect the native species of terrestrial isopods, in contrast to the introduced species, are very diverse and do not group within the Oniclade. The sequences present in B. meeusei are not related to any other lineage present in crustaceans, nor to any other known supergroup of Wolbachia. This study is the first to demonstrate the presence of these bacteria in a nematode of the family Mermithidae, Agamermis sp., an endoparasite of Armadillidium vulgare. Since the sequences from the parasite and the host are identical, it is possible that a horizontal transmission event occurred between the two. Finally, the presence of Wolbachia was examined in species that are ecologically associated with terrestrial isopods (predators, parasites, phoretic species, and animals that live under the same ecological conditions). Among the associated species, the infection was recorded only in the parasitic nematode and in the phoretic mites. Whereas the lineages of the isopod host and of the nematode proved to be very similar, those of the phoretic mites showed no phylogenetic relationship with those of their phoront Balloniscus glaber. Interestingly, the sequences present in the mites are closely related to those of B. meeusei, although further studies are necessary to clarify this finding.

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Appel, Carina de Souza. « Análise e descrição de estruturas temporárias presentes no período ovígero de isópodos terrestres (Crustacea, Oniscidea) ». reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2011. http://hdl.handle.net/10183/142948.

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A presença do marsúpio fechado possibilitou aos isópodos terrestres a total independência do meio aquático para a reprodução, permitindo aos mesmos a colonização de habitats terrestres variados. Em seu interior, a prole é nutrida e oxigenada através de estruturas temporárias, chamadas cotilédones, as quais surgem durante o período ovígero das fêmeas e são exclusivas do grupo Crinocheta. O presente estudo teve como objetivo descrever padrões dos cotilédones, analisados em 37 espécies de isópodos terrestres distribuídas entre as famílias: Agnaridae, Armadillidae, Armadillidiidae, Balloniscidae, Bathytropidae, Detonidae, Dubioniscidae, Philosciidae, Platyarthridae, Porcellionidae, Pudeoniscidae, Scleropactidae e Trachelipodidae, verificando se ocorre variação de comprimento ao longo das fases de desenvolvimento embrionário, sendo que para isto foram selecionadas seis espécies: Armadillidium nasatum, A. vulgare, Atlantoscia floridana, Balloniscus sellowii, Benthana cairensis e Porcellio scaber. Armadillidium vulgare e B. sellowii também foram estimados quanto à proporção comprimento dos cotilédones/ tamanho da fêmea. Entre as 13 famílias estudadas foram identificados seis formatos (tipos) de cotilédones e sete arranjos diferentes de número e distribuição. O comprimento foi estabelecido como: curto, médio e longo. Armadillidium vulgare, A. floridana e B. cairensis não apresentaram diferença no comprimento dos cotilédones durante os estágios embrionários sendo que este foi evidenciado para as demais espécies, uma vez que B. sellowii e P. scaber apresentaram aumento da fase de ovo para embrião, diminuindo na fase de manca. Já em A. nasatum ocorre um aumento gradual até a fase de manca, onde então regridem drasticamente. O comprimento dos cotilédones de A. vulgare e B. sellowii é proporcional ao tamanho da fêmea. Durante os estudos realizados outra novidade foi registrada: a presença de uma “extensão marsupial”. Para maiores informações sobre esta estrutura, foi necessário identificar quais espécies a apresentavam, o número de indivíduos abrigados em seu interior e diferenças na estrutura entre as espécies que portavam tal extensão e as que possuem o marsúpio fechado restrito aos cinco pares de oostegitos. Seis espécies apresentaram extensão marsupial, a qual possibilita o abrigo de aproximadamente ¼ do total da prole. XI Este marsúpio não apresenta formato distendido como o encontrado nas demais espécies o que vem a influenciar diretamente a alimentação da fêmea, pois com o desenvolvimento da prole ocorrendo em direção aos órgãos desta, conforme avançam as fases, aumenta a pressão interna, comprimindo seu interior. As diferenças morfológicas registradas aqui representam estratégias reprodutivas adotadas pelas espécies, ao longo da evolução, podendo estar relacionadas (ou não) à filogenia dos grupos.
The presence of the closed brood pouch made it possible for terrestrial isopods to have full independence of the aquatic environment for reproduction, allowing them to colonize varied terrestrial habitats. Inside, the offspring is nourished and oxygenated by temporary structures, called cotyledons, which emerge during the ovigerous period of females and are unique to the group Crinocheta. This study aims to describe patterns of cotyledons, analyzed in 37 species of terrestrial isopods distributed among the families: Agnaridae, Armadillidae, Armadillidiidae, Balloniscidae, Bathytropidae, Detonidae, Dubioniscidae, "Philoscidae" Platyarthridae, Porcellionidae, Pudeoniscidae, Scleropactidae and Trachelipodidae , checking if there is variation in length along the stages of embryonic development, and for this, six species were selected as models: Armadillidium nasatum, A. vulgare, Atlantoscia floridana Balloniscus sellowii, Porcellio scaber and Benthana cairensis. Armadillidium vulgare and B. sellowii were also estimated concerning the proportion of cotyledon length / female size. Among the 13 studied families six formats (types) of cotyledons were identified as well as seven different arrangements of numbers and distribution. The length was established as: short, medium and long. Armadillidium vulgare, A. floridana and B. cairensis showed no difference in the length of the cotyledons during the embryonic stages while this was evidenced for the other species, since B. sellowii and P. scaber showed increased egg stage to the embryo, decreasing during the manca. Nevertheless in A. nasatum a gradual increase until the phase of manca occurs, which then regresses dramatically. The length of the cotyledons of A. vulgare and B. sellowii is proportional to female size. XIII During the carried out studies another new feature was recorded: the presence of an " marsupial extension." For obtaining further information about this structure it was necessary to identify the species that presented it, the number of individuals housed within, and differences in structure between species that harbored such extension and the others which had the closed pouch restricted to five pairs of oostegits. Six species showed marsupial extension, which provides shelter for approximately a quarter of the total offspring. This brood pouch does not have a distended format as the one found in other species, which directly influences the feeding of the female, because due to the fact that the offspring development occurs towards its organs as the stages advance, internal pressure increases, compressing its interior. The morphological differences reported here represent reproductive strategies adopted by the species, through evolution and could be related (or not) to the phylogeny of the groups.

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Cardoso, Giovanna Monticelli. « Revisão taxonômica e análise filogenética em Bathytropidae Vandel, 1952 (CRUSTACEA : ISOPODA : ONISCIDEA) ». reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2017. http://hdl.handle.net/10183/163675.

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A ordem Isopoda é um dos o grupo mais diverso dentre os crustáceos, sendo composta por dez subordens. Os representantes da subordem Oniscidea, conhecidos como “tatuzinhos de jardim”, obtiveram grande sucesso no domínio do ambiente terrestre. Para isso, foram necessárias várias adaptações morfológicas, fisiológicas e comportamentais, tais como comportamento gregário para diminuição da perda de água, presença de marsúpio fechado para reprodução e a presença de pulmões pleopodais. Apesar do grupo apresentar ampla uma distribuição geográfica, as espécies apresentam limitada capacidade de dispersão. Essa baixa dispersão resulta em isolamento de populações e alta diversidade genética. Dessa forma, o número de espécies dos isópodos é subestimado, sendo necessários mais esforços taxonômicos a fim de ampliar o conhecimento para o grupo. Frequentemente, revisões taxonômicas resultam em ampliação do número de espécies, reforçando a importância destes estudos para o grupo. Identificações usualmente se baseiam em pequenas variações morfológicas, o que muitas vezes dificulta a distinção entre espécies, sendo dados moleculares representam uma importante ferramenta para a delimitação das relações de parentesco entre espécies. O gênero Neotroponiscus ocorre na America do Sul e possui uma grande diversidade de espécies distribuídas ao longo da Mata Atlântica Brasileira. Oito espécies são conhecidas na literatura e foram revisadas para o levantamento de caracteres, necessários para os estudos filogenéticos. Além disso, neste trabalho, cinco novas espécies novas foram identificadas. Com base em dados morfológicos e moleculares a monofilia do gênero foi testada, e o grupo foi recuperado como monofilético. As relações de parentesco entre Neotroponiscus e os integrantes da família Bathytropidae foi testada e a família foi recuperada como um grupo parafilético, corroborando para hipóteses anteriores. Estudos futuros com uma abordagem biogeográfica serão importantes para elucidar os padrões de distribuição das espécies de Neotroponiscus.
The order Isopoda is one of the most diverse groups among crustaceans. Species from the suborder Oniscidea, commonly known as woodlice, were very successful in conquering the terrestrial environment. For that, many morphological, physiological and behavioral adaptations were necessary, such as, closed marsupium for reproduction, presence of pleopodal lungs, and gregarious behavior to diminish water losses. Although the group has large geographical distribution, species have limited dispersion capacity. This low dispersion results in population isolation and high genetic diversity. Therefore, the number of species of terrestrial isopods is greatly underestimated and more taxonomical studies are necessary in order to broaden the knowledge on the group. Taxonomical revisions on terrestrial isopods frequently result in higher number of species reinforcing the importance of these studies for the fore the mentioned group. Identification is usually based on subtle morphological differences, so molecular data is an important tool to elucidate the relationship within the group. The genus Neotroponiscus occurs in South America and has high species diversity throughout the Atlantic Forest. A total of eight species are known from the literature and were reviewed to identify characters that are necessary for phylogenetic studies. In this study, five new species were identified and described. Based on morphological and molecular data, the monophyly of the group was tested and the group was confirmed as monophyletic. The relationship between Neotroponiscus and the other species from the family Bathytropidae were also tested, showing that the family represents a paraphyletic group, which corroborates previous suggestions. Future studies with biogeographic approuch will be important to elucidate the distribution pattern of the genus Neotroponiscus.

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Lavastre, Véronique. « Evénements sédimentaires, diagénétiques et post-diagénétiques dans la formation argileuse du Callovo-Oxfordien (Bassin de Paris, France) : enregistrement isotopique des minéraux et de l'eau porale ». Paris 7, 2002. http://www.theses.fr/2002PA077103.

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KERR, ROBERT. « L'utilisation des isotopes stables dans les etudes des transformations metaboliques : applications aux orthomethoxybenzamides ». Université Louis Pasteur (Strasbourg) (1971-2008), 1988. http://www.theses.fr/1988STR13173.

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Mazzei, Veronica. « Bioaccumulo di cadmio e piombo e biomarkers di esposizione e di effetto in alcune specie di isopodi oniscidei (Crustacea) ». Doctoral thesis, Università di Catania, 2012. http://hdl.handle.net/10761/1141.

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Scopo della presente tesi di Dottorato è stato quello di valutare, utilizzando un protocollo sperimentale basato sulla somministrazione di cibo contaminato con diverse concentrazioni di due metalli pesanti, cadmio e piombo, la capacità di bioaccumulo e le conseguenti risposte biologiche fornite (biomarkers) da tre specie di isopodi oniscidei - Armadillidium granulatum Brandt, Armadillidium vulgare (Latreillei), Porcellio laevis Latreille - presenti ed abbondanti in diverse aree della Sicilia particolarmente interessate da fenomeni di inquinamento ambientale, al fine di verificare il loro possibile impiego in futuri programmi di biomonitoraggio. Sono stati oggetto di indagine: a) l accumulo dei metalli mediante impiego di spettrometria di massa a plasma accoppiato induttivamente (ICP-MS); b) le alterazioni morfologiche, istologiche ed ultrastrutturali indotte a carico dell epatopancreas, principale organo di accumulo dei metalli; c) l espressione di molecole indicatrici dello stress conseguente al bioaccumulo dei metalli, quali metallotioneine (MT) e heat shock proteins 70 (Hsp70) analizzata mediante metodi immunocitochimica; d) l identificazione ed il sequenziamento del gene responsabile dell espressione delle metallotioneine mediante indagini molecolari. I risultati conseguiti hanno dimostrato che negli isopodi oniscidei, l accumulo dei metalli si realizza in maniera correlata alla concentrazione utilizzata ma in modo variabile in relazione al metallo ed alla specie saggiata. Tutte e tre le specie isopodi hanno dimostrato, infatti, una capacità di accumulo del Cd spiccatamente superiore rispetto al Pb; A. vulgare è stata la specie capace del maggior accumulo di Pb, soprattutto alle concentrazioni più elevate del metallo somministrate, mentre P. laevis, ha mostrato la maggiore capacità di accumulo del Cd, tanto elevata da risultare letale per tutti gli individui trattati per la più alta concentrazione tra quelle saggiate. La somministrazione delle concentrazioni più elevate di entrambi i metalli ha determinato sensibili alterazioni e della generale organizzazione morfologica ed istologica dei tubuli dell epatopancreas e dell organizzazione ultrastrutturale delle cellule dell epitelio dell organo, alcune delle quali potrebbero essere utilizzate quali efficaci biomarkers di esposizione. L impiego di anticorpi anti-MT ed anti-Hsp70 si è rivelato efficace ai fini di evidenziare la presenza delle MT e delle Hsp70 nell epitelio dell organo, apprezzabile in maniera differenziata per intensità e localizzazione in relazione al metallo considerato, aspetti che potrebbero rappresentare utili biomarkers di effetto. Le indagini molecolari rivolte al sequenziamento del gene responsabile dell espressione delle metallotioneine, basate su un protocollo già efficacemente impiegato per altre specie di invertebrati ivi compresi i crostacei decapodi, non hanno avuto successo a causa di una persistente contaminazione fenolica dell RNA, estratto dal pool di epatopancreas. In conclusione, la ricerca ha confermato quanto già noto circa l eccellente ruolo che gli isopodi oniscidei possono ricoprire quali bioindicatori e bioaccumulatori dell inquinamento da metalli pesanti evidenziando, inoltre, che la capacità di bioaccumulo si realizza in maniera specie-specifica nei confronti dei diversi metalli e che, pertanto, essa deve essere preliminarmente valutata in vista di un loro impiego nei programmi di biomonitoraggio.

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Rios, Ana Paula de Jesus. « Isótopos de O e H na análise de anomalias de bário na região de Marília - SP ». Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/44/44138/tde-27032017-093451/.

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Na última década foram encontradas concentrações anômalas de bário em poços de abastecimento do Sistema Aquífero Bauru (SAB), com casos de ocorrências de teores acima do limite de potabilidade (0,7 mg/L). Estas concentrações foram encontradas pelo monitoramento da CETESB e por estudos anteriores. Tavares (2013) e Crespi (2013) indicam que a contaminação nesta área tem origem natural, advinda da lixiviação da cimentação carbonática da Formação Marília. Utilizando dados bibliográficos e expandindo o estudo para toda a região do Espigão de Marília, este trabalho visou aprofundar o conhecimento sobre esta anomalia e tentar compreender o seu comportamento com auxílio de dados isotópicos (O e H) de chuva e água subterrânea. Para o entendimento da anomalia foi construído um banco de dados com os Autos de Outorga de poços do DAAEE, CETESB e CPRM. Após o cadastro destes dados, foram confeccionadas as seções geológicas, o modelo conceitual de fluxo da área, e um modelo hidrogeológico. Após esta etapa foram selecionados 21 poços para as duas primeiras campanhas de amostragem ao longo do ano hidrológico e 8 poços para uma terceira campanha de amostragens ao longo do ano hidrológico. Simultaneamente foi instalado no DAAEE de Marília um coletor de chuva para coletar amostras desde junho de 2014 até dezembro de 2015 para a confecção da reta meteórica local. Os resultados analíticos dos poços foram tratados agrupando-os de acordo com sua geologia, observando-se padrões de distribuição dos parâmetros químicos analisados, bem como dos isótopos. Foi possível notar que há contaminação por cloreto e nitrato em alguns poços. A contaminação de bário ocorre em diferentes pontos, não estando restrita a apenas uma formação. Sem nenhuma relação com os demais componentes antrópicos, esta anomalia se confirma natural. Os altos teores de bário também aparecem em locais com uma maior variedade geológica. A análise dos isótopos de hidrogênio e oxigênio das amostras mostrou que as águas amostradas são mais empobrecidas que as de chuva, até mesmo as mais rasas. Em teste de bombeamento foi possível acompanhar a evolução da assinatura com a profundidade. O que pode ser concluído é que a anomalia de bário ocorre em todo o Espigão, em geral em poços com filtros nas Formações Marília e Adamantina, que possuam um teor mais elevado de magnésio, não necessariamente tendo uma influência antrópica.
In the last decade, anomalous concentrations of barium were found in supply wells of Bauru Aquifer System (BAS), with occurrences of levels above the drinking limit (0.7 mg/L). These concentrations were found by CETESB monitoring and some previous studies. Tavares (2013) and Crespi (2013) indicate that contamination in this area has natural origin, from the leaching of carbonate cementation of Marília Formation. Using bibliographic data and expanding the study to the entire region of the Espigão de Marília this study aimed to increase knowledge about this anomaly and try to understand their behavior with aid of isotopic data (O and H) of rain and groundwater. For the understanding of the anomaly, a database was built with information from DAAEE, CETESB and CPRM wells. After the register of this database, some geological sections were made, the groundwater flow conceptual model for the area, and a geological model. After this step, 22 wells were selected for the three sampling campaigns. At the same time was installed in DAAEE of Marília a rain collector that operated from middle of 2014 by the end of 2015, to construct a Local Meteoric Water Line. The wells have been grouped according to the geology, and some patterns were discovered. It was possible to notice that there is a problem about chloride and nitrate contamination. Barium contamination appeared at various points, not being restricted to just one Formation. Without any relation with man-made components, according to the bibliography, this anomaly confirms natural. High levels of barium also appear in places with greater geological variety. The analysis of the isotopes of hydrogen and oxygen of the samples showed that the waters sampled are isotopic depleted compared to the rain. In pumping test was possible to monitor the evolution of the signature with the depth. It is possible to conclude that the barium anomaly is spread all over the Espigão de Marília, in general in wells with filters in Marília and Adamantina Formations, which have a higher content of magnesium, not necessarily having a human influence.

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Modlitbová, Pavlína. « Zavedení kontaktních testů ekotoxicity pro hodnocení terrestrických ekosystémů ». Doctoral thesis, Vysoké učení technické v Brně. Fakulta chemická, 2016. http://www.nusl.cz/ntk/nusl-261219.

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This dissertation thesis is focus on using toxicity tests with testing organism - terrestrial isopod Porcellio scaber. This organism is use for toxicity assessment of selected anorganic compunds which could contaminate terrestrial ecosystem. This organism was selected for several reasons - sophisticated test methodology; well known biology of these animals and their ecological relevance. Besides classical endpoints such as mortality, change in mass of test specimens and the effect of the presence and concentration of contaminants onto food consumption; we monitored changes in the morphometric characteristics at the level of tissues and cells, the cytotoxicity and possibly bioaccumulation in various parts of the body of the organism. Selected test substance in this thesis were nanoparticles and inorganic salts. Wherein for chosen gold nanoparticles was carried out a complete study presents several levels of organization of living matter (organism, tissue, cell). For selected salts compound, this study was carried out on the behavior of organisms and classical endpoints.

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Riehl, Torben [Verfasser], et Angelika [Akademischer Betreuer] Brandt. « A phylogenetic approach to the classification of macrostylid isopods and faunal linkages between the deep sea and shallow-water environments / Torben Riehl. Betreuer : Angelika Brandt ». Hamburg : Staats- und Universitätsbibliothek Hamburg, 2014. http://d-nb.info/1053811683/34.

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Fraj-Lagha, Mehdia. « Biodiversité des arthropodes dans les agroécosystèmes. Application à l'échelle de la basse vallée Majerda en Tunisie ». Thesis, Poitiers, 2013. http://www.theses.fr/2013POIT2266/document.

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L'étude de la biodiversité de la macrofaune et des Oniscoïdes dans l'agroécosystème Majerda (BVM) a été réalisée sur 2 années successives sur 15 parcelles durant 4 saisons de l'année 2008-2009 et sur 11 parcelles de l'année 2009-2010. L'analyse a été faite en fonction des cultures les plus représentées dans la BVM (l'arboriculture, culture maraîchère, fourragère et légumineuse). L'échantillonnage a été réalisé par piégeage. Au total, 19 groupes taxonomiques ont été collectés. Les résultats montrent une variation saisonnière de la diversité de la macrofaune en fonction des parcelles. Les Coléoptères, les Oniscoïdes, les Hyménoptères, les Diptères, les Orthoptères et les Araignées sont les plus constants et abondants dans la BVM. Les Oniscoïdes sont abondants dans les parcelles en cultures fourragères. En passant des parcelles du milieu terrestre vers celui côtier, un gradient ascendant de la diversité de la macrofaune a été observé. Neuf espèces ont été collectées. Porcellio laevis est la plus fréquente durant toutes les saisons d'étude. En fonction de cultures, l'effectif et la richesse spécifique les plus importants ont été enregistrés dans les cultures fourragères et dans la céréaliculture. En fonction des secteurs, les Isopodes terrestres sont abondants dans les parcelles du secteur Pont de Bizerte qui sont irriguées par le mode aspersion et par les eaux usées. L'étude de la variation interannuelle montre qu'il existe un effet du facteur année sur la diversité de la macrofaune et des espèces d'Oniscoïdes. Les espèces d'Oniscoïdes sont corrélées avec la conductivité, la teneur du sol en Mg2+ Ca2+, K+ et de la granulométrie du sol
In Tunisia, few studies on the macrofauna and species diversity of terrestrial isopods in the agroecosystems were performed. To fill this gap, the spatio-tempral (plots, sectors and season) diversity of macrofauna and Oniscidea was analysed. We studied the distribution of Isopods in Majerda agroecosystems related to cultivation types (orchards, market gardening, vegetable crops), irrigations systems (sprinkler, surface and drip) and soil physico-chemical characteristics. Sampling was carried out with pitfalls traps during in 15 plots during 2008-2009 and 11 plots during 2009-2010. Nineteen groups of macrofauna was found. Coleoptera, Oniscidea, Hymenoptera, Diptera, Othoptera and Aranea were the most present and abundant. Isopods were abundant in autum in the vegetable crops cultivation. In the coastal plots (Ghar El Melh sector) diversity was higher than in the terrestrial plots (Utique sector). Nine species of terrestrial isopods belonging to 6 genera were identified. Porcellio laevis was the most frequent species in all seasons. According to cultivation types, the number of individuals and the species richness were important in vegetable crops and barely cultivation. The spatial distribution of Oniscidea showed that isopods were abundant in the plots of Pont of Bizerte irrigated by sprinkler systems and wastewater. Year factor affected the diversity of fauna and isopods. Oniscidea species distribution was correlated to conductivity, texture and the content of Mg2+ Ca2+ and K+ of soil

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Ruangchai, Sukhum [Verfasser]. « The hierarchical organisation of cuticle in the basis-coxa joint of terrestrial isopods : variations in structure and composition adapt the cuticle for movement, support and stability / Sukhum Ruangchai ». Ulm : Universität Ulm, 2019. http://d-nb.info/1181190495/34.

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Bugs, Priscila da Silva. « Ocorrência e distribuição de isópodos terrestres (Crustacea : Oniscidea) em três ambientes florestais na Serra Geral, Rio Grande do Sul ». reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2010. http://hdl.handle.net/10183/24096.

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A subordem Oniscidea Latreille, 1829 é a única ordem de Isopoda que abriga espécies verdadeiramente terrestres. Formam um importante e dominante componente nas comunidades de meso e macro-decompositores de solo. Suas atividades causam um impacto considerável na decomposição através da promoção da respiração microbial e alterações na química dos detritos. No presente estudo investigou-se a abundância, diversidade e composição de espécies de isópodos terrestres em três formações vegetais, na Serra Geral do Rio Grande do Sul – Brasil. A área compreende duas formações espontâneas (Mata Primária e Mata Secundária) e área de plantação de Pinus abandonada, em estágio de sucessão. Para cada área, foram consideradas duas subáreas, contendo dois transectos com 5 armadilhas de queda em cada um, as quais ficaram operantes de 2001 a 2002. Os dados obtidos possibilitaram a realização de inferências sobre as características populacionais apresentadas por duas espécies: Atlantoscia floridana e Balloniscus glaber. Atlantoscia floridana é a espécie mais frequente nas três áreas: 145 indivíduos em Mata Primária, 194 em Mata Secundária e 105 em plantações de Pinus. Balloniscus glaber apresentou abundância de 80 indivíduos em Mata Primária, 82 em Mata Secundária e um indivíduo em plantações de Pinus. A Análise de Similaridade revelou diferença quantitativa entre as áreas, mas não diferença qualitativa. Foram identificados Doubletons para mata primária (Alboscia silveirensis) e plantação de Pinus (Benthana araucariana) e Singletons para a mata secundária (A. silveirensis, B. araucariana e Styloniscus otakensis) e plantação de Pinus (B. glaber). Obteve-se também o registro de uma Duplicata (A. silveirensis) para mata primária e secundária. A Proporção Sexual Operacional (OSR) de A. floridana seguido do Teste G, não verificou diferença entre a proporção sexual apresentada dentro das áreas ou em relação ao esperado 1:1. Atlantoscia floridana apresentou correlação significativa entre o tamanho da fêmea e o tamanho da prole para as três áreas. A menor fêmea ovígera foi encontrada em área de Pinus (0.968mm). Fêmeas ovígeras e pós-ovígeras ocorreram nas estações de verão, outono e primavera (Mata Primária e Plantação de Pinus) e nas quatro estações (Mata Secundária). Quanto à abundância de A. floridana não apresentou diferença significativa entre as áreas. Representantes de todas as classes ocorrem em todas as áreas. Para Balloniscus glaber a Proporção Sexual Operacional (OSR) seguido do Teste G verificou diferença quanto à proporção esperada de 1:1, mas não diferença entre as áreas. Não foi apresentada correlação significativa entre o tamanho da fêmea e o tamanho da prole na Mata Primária e Mata Secundária. Fêmeas ovígeras e pósovígeras ocorreram nas estações de verão e outono (Mata Primária e Mata Secundária). Quanto à abundância B. glaber não apresentou diferença significativa entre as áreas. Representantes de todas as classes ocorrem na Mata Primária e Mata Secundária. Em Plantação de Pinus ocorreu o registro de somente uma fêmea no verão de 2001. A menor fêmea ovígera foi encontrada em Mata Primária.
The suborder Oniscidea Latreille, 1829 is the only Isopoda order that has truly terrestrial species. This group is an important and dominant portion of the soil meso and macro faunal community. Their activity causes considerable impact in decomposition through the increase on microbial respiration and detritus chemical alteration. The present study investigated the abundance, diversity, and species composition of terrestrial isopods in three vegetal formations in the Serra Geral of Rio Grande do Sul – Brazil. The area comprises two spontaneous formations (primary and secondary forests) and an abandoned Pinus plantation in succession stage. For each area, two sub-areas were taken into account; constituting two transects containing 10 pitfall traps each, that where kept during 2001 and 2002. The obtained data permitted inferences regarding the population characteristics of two species: Atlantoscia floridana and Balloniscus glaber. Atlantoscia floridana was the most frequent species in the three areas: 145 individuals in primary forest, 194 in secondary forest and 105 in Pinus plantation. Balloniscus glaber presented an abundance of 80 individuals in primary forest, 82 in secondary forest and one individual in Pinus plantation. The similarity analysis revealed quantitative but not qualitative difference between the areas. Doubletons were identified in primary forest (Alboscia silveirensis) and Pinus plantation (Benthana araucariana) and Singletons were identified for secondary forest (A. silveirensis, B. araucariana and Styloniscus otakensis) and Pinus plantation (B. glaber). One Duplicata (A. silveirensis) was also registered for primary and secondary forest. The operational sexual proportion (OSR) of A. floridana followed by G Test was not different between observed and expected 1:1 sexual proportion in the areas. Atlantoscia floridana presented significant correlation between female size and offspring number in the three areas. The smallest ovigerous female was found in the area with Pinus (0.968mm). There was no difference in the abundance of ovigerous and post ovigerous females. Both females were present in the samples from summer, fall and spring (primary forest and Pinus plantation) or in the four seasons (secondary forest). Regarding the abundance of Atlantoscia floridana, there was no significant difference between the different areas. Individuals of all classes were present in all areas. The OSR of B. glaber had no significant difference between the sampled number of females and males. Through G Test it was verified difference from the expected 1:1 proportion, but no difference between the areas. There was no significant correlation between female size and offspring number for primary and secondary forest. There was no significant difference regarding the abundance of ovigerous and post ovigerous females. Both females were present in the samples from summer and fall (primary and secondary forest). There was no significant difference in abundance of B. glaber between the areas. Individuals of all classes were present in primary and secondary forest. In Pinus plantation, there was only one female in the summer of 2001. The smallest ovigerous female was found in primary forest.

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Volckaert, Fabrice. « Dosage spectroscopiques du péroxyde d'hydrogène et de diverses formes oxydées de l'azote dans la troposhère ; fiabilité de ces méthodes. : Impacts sur la simulation numérique ; conception de diagrammes isopleths généralisés ». Lille 1, 1993. http://www.theses.fr/1993LIL10048.

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Industries et transports constituent les deux sources principales d'emission de polluants primaires, responsables de la formation des oxydants photochimiques. Parmi ces polluants dits secondaires se trouve h2o2, compose entrant dans le cycle de formation de h2so4. Une methode de dosage de h2o2 par spectroscopie de fluorescence est decrite. No2 est un precurseur important de la pollution atmospherique et pour cette raison, il est necessaire de le mesurer avec precision, ce qui n'a pas toujours ete le cas dans le passe. Nous avons donc teste de maniere approfondie le lma-3: un analyseur dosant no2 par chimiluminescence et sommes parvenues a des resultats tres satisfaisants. Nous decrivons egalement un systeme de dosage automatise des especes: no, no2, pan, hno3, hno2, qui utilise les qualites du lma-3 et les defauts de l'ac30m: appareil convertissant no2 en no mais aussi differents oxydes d'azote. Nous avons aussi modifie l'ac30m et augmente sa sensibilite. La derniere partie de ce memoire est consacree a la modelisation dont l'objectif est la mise au point de strategies de controle des emissions visant a reduire la formation des oxydants photochimiques. Les trois problemes abordes sont: la simulation du comportement de h2o2, l'effet de mesure erronees de no2 et enfin la conception de diagrammes isopleths generalises.

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Morgado, Rui Guilherme da Costa. « Single and joint effects of natural and chemical stressors to the terrestrial isopod Porcellionides pruinosus ». Doctoral thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/14138.

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Doutoramento em Biologia
Environmental contamination and climate changes constitute two of the most serious problems affecting soil ecosystems in agricultural fields. Agriculture is nowadays a highly optimized process that strongly relies on the application of multiple pesticides to reduce losses and increase yield production. Although constituting, per se, a serious problem to soil biota, pesticide mixtures can assume an even higher relevance in a context of unfavourable environmental conditions. Surprisingly, frameworks currently established for environmental risk assessments keep not considering environmental stressors, such as temperature, soil moisture or UV radiation, as factors liable to influence the susceptibility of organisms to pesticides, or pesticide mixtures, which is raising increasing apprehension regarding their adequacy to actually estimate the risks posed by these compounds to the environment. Albeit the higher attention received on the last few years, the influence of environmental stressors on the behaviour and toxicity of chemical mixtures remains still poorly understood. Aiming to contribute for this discussion, the main goal of the present thesis was to evaluate the single and joint effects of natural stressors and pesticides to the terrestrial isopod Porcellionides pruinosus. The first approach consisted on evaluating the effects of several abiotic factors (temperature, soil moisture and UV radiation) on the performance of P. pruinosus using several endpoints: survival, feeding parameters, locomotor activity and avoidance behaviour. Results showed that these stressors might indeed affect P. pruinosus at relevant environmental conditions, thus suggesting the relevance of their consideration in ecotoxicological assays. At next, a multiple biomarker approach was used to have a closer insight into the pathways of damage of UV radiation and a broad spectrum of processes showed to be involved (i.e. oxidative stress, neurotoxicity, energy). Furthermore, UV effects showed to vary with the environment medium and growth-stage. A similar biomarker approach was employed to assess the single and joint effects of the pesticides chlorpyrifos and mancozeb to P. pruinosus. Energy-related biomarkers showed to be the most differentiating parameters since age-classes seemed to respond differently to contamination stress and to have different metabolic costs associated. Finally, the influence of temperature and soil moisture on the toxicity of pesticide mixtures was evaluated using survival and feeding parameters as endpoints. Pesticide-induced mortality was found to be oppositely affected by temperature, either in single or mixture treatments. Whereas chlorpyrifos acute toxicity was raised under higher temperatures the toxicity of mancozeb was more prominent at lower temperatures. By the opposite, soil moisture showed no effects on the pesticide-induced mortality of isopods. Contrary to survival, both temperature and soil moisture showed to interact with pesticides to influence isopods’ feeding parameters. Nonetheless, was however the most common pattern. In brief, findings reported on this thesis demonstrated why the negligence of natural stressors, or multiple stressors in general, is not a good solution for risk assessment frameworks.
A contaminação ambiental e as alterações climáticas são duas das mais sérias ameaças aos ecossistemas edáficos. A agricultura é atualmente uma prática altamente otimizada da qual a aplicação de vários pesticidas é uma componente essencial. Apesar da sua importância, o uso de pesticidas pode implicar elevados custos ambientais, particularmente quando em misturas. Não obstante, no contexto de condições ambientais desfavoráveis estas misturas podem ainda revestir-se de uma relevância acrescida. Estudos recentes têm demonstrado que a ocorrência de stressores naturais, como a temperatura, humidade do solo ou radiação ultravioleta, pode influenciar a toxicidade de pesticidas, o que tem suscitado uma crescente apreensão relativamente à eficácias das avaliações de risco ambiental. Esta preocupação prende-se principalmente pelo facto de estes estudos não terem em conta a complexidade das interações entre múltiplos stressores. De forma a contribuir para este debate, com a presente tese pretendeu-se avaliar os efeitos individuais e combinados de stressores naturais e pesticidas no isópode terrestre Porcellionides pruinosus. A primeira fase do estudo consistiu na avaliação dos efeitos individuais de vários factores abióticos (temperatura, humidade do solo e radiação ultravioleta) na performance de P. pruinosus usando vários parâmetros como a sobrevivência, parâmetros alimentares, atividade locomotora e evitamento de condições adversas. Os resultados demonstram claramente a importância que estes stressores podem assumir na performance dos organismos e enfatizam a urgência de serem tidos em conta em avaliações de risco ambiental. De seguida foram estudados os efeitos da radiação ultravioleta recorrendo a um conjunto de biomarcadores relacionados com diferentes processos, no qual ficou patente a influência do meio de exposição e da idade dos organismos na vulnerabilidade a este stressor. Uma abordagem semelhante foi desenvolvida para avaliar os efeitos individuais e combinados dos pesticidas clorpirifos e mancozebe em P. pruinosus. Os adultos e juvenis expostos pareceram exibir diferentes padrões de resposta aos pesticidas relativamente ao balanço energético e custos metabólicos. Finalmente foi avaliada a influência da temperatura e da humidade do solo na toxicidade desta mistura binária. No que diz respeito à sobrevivência dos isópodes, os pesticidas mostraram ser influenciados de maneira oposta pela temperatura. Enquanto a toxicidade de clorpirifos pareceu aumentar com o aumento da temperatura, os efeitos do mancozebe foram mais proeminentes a temperaturas baixas. Pelo contrário, a humidade do solo não mostrou influenciar significativamente a mortalidade causada pelos pesticidas. No que diz respeito aos parâmetros alimentares foram detectadas várias interações entre ambos os stressores naturais e os pesticidas, apesar de a aditividade de efeitos ter sido o resultado mais frequente. Em conclusão, os resultados reportados ao longo desta tese reforçam o perigo associado à negligência de stressores naturais, ou mesmo da conjugação de múltiplos stressores em geral, para as avaliações de risco ambiental.

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Badawi, Myriam. « Base génétique moléculaire de la féminisation induite par la bactérie endosymbiotique Wolbachia ». Thesis, Poitiers, 2014. http://www.theses.fr/2014POIT2306/document.

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La symbiose est l'un des principaux moteurs de l'évolution. Le génotype du symbiote est capable d'altérer le phénotype de l'hôte, et vice-versa : c'est le « phénotype étendu ». Dans ce contexte, les endosymbioses à Wolbachia sont remarquables. Cette bactérie intracellulaire est un parasite de la reproduction capable d'induire la féminisation des mâles génétiques ou l'incompatibilité cytoplasmique chez ses hôtes crustacés isopodes terrestres. Actuellement, aucun mécanisme moléculaire régissant ces effets n'est connu. Dans le but d'identifier des gènes impliqués dans la féminisation, nous avons utilisé une approche intégrative qui combine à la fois des analyses génomiques, d'expression de gènes et phénotypiques. Nous avons tout d'abord analysé l'évolution moléculaire de la voie de la recombinaison homologue dans les génomes de Wolbachia, source importante de plasticité génomique pouvant être liée à la diversité des phénotypes. Ensuite, afin d'effectuer des études comparatives qui augmenteraient considérablement la compréhension des mécanismes de la féminisation, nous avons établi un système où la souche féminisante wVulC féminise deux hôtes isopodes (hôte naturel : Armadillidum vulgare : hôte hétérologue : Cylisticus convexus) présentant un timing différent de la différenciation sexuelle. En effet, l'effet féminisant étant supposé avoir lieu avant ou pendant la différenciation sexuelle, il est important de distinguer l'effet de Wolbachia dû à la différenciation sexuelle de celui dû au développement. Enfin, une approche par gènes candidats (du séquençage de génome bactérien à l'analyse comparative d'expression de gènes bactériens durant le développement de l'hôte) a permis de déterminer une liste réduite de 29 gènes (parmi les 1885 gènes de wVulC) dont la probabilité qu'ils soient impliqués dans la féminisation est élevée. Le rôle potentiel de ces gènes candidats comme effecteurs supposés de la féminisation induite par wVulC est ensuite discuté. Ce travail contribue grandement à l'identification de facteurs potentiels d'endosymbiotes qui ont un impact évolutif sur la détermination du sexe de leurs hôtes
Symbiotic interactions are a major driver of evolution. The symbiont genotype is able to alter the host phenotype, and the other way round: it is called "the extended phenotype". In this respect, Wolbachia endosymbiosis is remarkable. This intracellular bacterium is a well-known reproductive parasite able to induce feminization of genetic males or cytoplasmic incompatibility in its terrestrial isopod crustacean hosts. Currently, no molecular genetic basis of these reproductive manipulations has been described. In order to identify genes involved in feminization, we used an integrative approach that combines genomic, gene expression and phenotypic studies. We first analysed the molecular evolution of the homologous recombination pathway in Wolbachia genomes, an important source of genomic plasticity that can be linked with phenotypic diversity. Then, in order to perform comparative studies that will substantially improve the understanding of the molecular mechanisms of feminization, we established a system in which the feminizing strain wVulC feminizes two different isopod hosts (natural host: Armadillidium vulgare ; heterologous host Cylisticus convexus) that have a different sexual differentiation timing. Indeed, as feminization is thought to happen before or during sexual differentiation, it is important to distinguish the effect of Wolbachia due to sexual differentiation from that due to development. Finally, a gene candidate approach (from bacterial genome sequencing to comparative bacterial gene expression during host developement) allowed us to determine a reduced list of 29 genes (among the 1885 genes of wVulC) that have a high probability to be involved in feminization. The potential roles of these candidate genes as putative effectors of feminization induced by wVulC is then discussed. This work substantially contributes to the identification of putative endosymbiont factors that have an evolutionary impact on sex determination of their hosts

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Ramirez, Edson. « Interprétation de la varaibilité climatique. Enregistrée dans les carottes de glace à partir des isotopes stables de l'eau : cas des Andes tropicales ». Paris 6, 2003. http://www.theses.fr/2003PA066574.

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Araújo, Ronaldo Kanopf de. « DINÂMICA DA CONTAMINAÇÃO POR EFLUENTE SANITÁRIO EM ÁREA DE UM CAMPUS UNIVERSITÁRIO ». Universidade Federal de Santa Maria, 2013. http://repositorio.ufsm.br/handle/1/7831.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
One of the biggest problems related to water pollution can currently be considered the release of untreated effluent, mainly from domestic sources, since the collection and treatment of these effluents is the sanitation service with greater coverage gap in Brazil. The effluent discharge directly into the ground without proper treatment can lead to the contamination of water, soil and groundwater, according to the site characteristics. Amid this reality, the degradation of natural resources in the Campus UFSM, due to increased academic population, has drawn attention of researchers and managers of the institution. Despite increasing pressure regarding environmental compliance for launching their effluents into water bodies, UFSM still presents difficulties in the disposal of wastewater. This research is justified by the importance of monitoring the release of wastewater Campus UFSM to study the possibility of natural attenuation in the environment and investigation of soil and groundwater. This research has been aimed at evaluating the natural attenuation of soil contamination by sanitary effluent in an area located on the campus of UFSM. Were performed ten wine sampling wastewater at four point sources of release of liquid effluents (FP-31, FP-32, FP-31A and FP-50), diluted effluent draining soil in four shallow wells (PMR- 02, PMR-03, PMR-04 and PMR-05), groundwater in two deep wells (PM-01, PM-02) and effluent into a drain channel after flow through the soil (EDC). Were collected from soil samples and ten individuals of aquatic macrophytes Typha domingensis, in two installments of the study area, called PC-01 and PC-02, for the analysis of heavy metals. Also as part of the environmental assessment of the area, made up the study of the density and diversity of terrestrial isopods. Considering the ten sampling campaigns carried out between August 2012 and February 2013, between the input point source effluents by FP-31, FP-32, FP-31A and FP-50 and channel drainage effluent (CDE), was observed an average reduction of 85.5% in flow, 50% in BOD5, 20, from 76.97% total solids, 91.22% of suspended solids, 99.8588% of total coliforms, 99.9623% E. coli. Based on these results, it was found that there is the natural attenuation process of carbonaceous organic matter, total coliforms, Escherichia coli and phosphate in the area. However, due to the fact that the transport of contaminants occurs in the vertical and horizontal profiles of the soil, reaching surface waters and groundwater, should be taken to improve sewage treatment systems in UFSM. Was found soil contamination by heavy metals barium, copper and zinc concentrations above the limits defined by CONAMA. 420/2009. We also found the presence of heavy metals in plant tissue of macrophyte Typha domingensis. It was verified diversity and isopods in soil density that can be bio-accumulators of heavy metals. The species were Oniscus asellus, which can be a body bioacumulator heavy metals and Philoscia muscurum, which can be a biomarker of contamination by the effluent discharge area.
Um dos maiores problemas relacionado à poluição das águas atualmente pode ser considerado o lançamento de efluentes sem tratamento, principalmente os de origem doméstica, uma vez que a coleta e o tratamento desses efluentes é o serviço de saneamento com maior déficit de cobertura no Brasil. O lançamento de efluentes diretamente no solo, sem tratamento adequado pode acarretar a contaminação dos cursos hídricos, do solo e da água subterrânea, de acordo com as características do local. Em meio a essa realidade, a degradação de recursos naturais no Campus da UFSM, devido ao aumento da população acadêmica, tem chamado atenção de pesquisadores e gestores da instituição. Apesar da crescente pressão quanto ao cumprimento da legislação ambiental para lançamento de seus efluentes nos corpos hídricos, a UFSM ainda apresenta dificuldades na destinação final de efluentes líquidos. Esta pesquisa justifica-se pela importância do monitoramento do lançamento de efluentes líquidos no Campus da UFSM para o estudo da possibilidade de atenuação natural no ambiente e da investigação da contaminação do solo e da água subterrânea. Nesta pesquisa tem-se como objetivo geral monitorar a contaminação do solo e da água subterrânea por efluente sanitário em uma área localizada no Campus da UFSM. Foram realizadas dez campanhas de amostragem de efluentes sanitários em quatro fontes pontuais de lançamento de efluentes líquidos (FP-31, FP-32, FP-31A e FP-50), de efluentes diluídos que escoam no solo em quatro poços rasos (PMR-02, PMR-03, PMR-04 e PMR-05), de água subterrânea em dois poços profundos (PM-01 e PM-02) e de efluente em um canal de drenagem após escoamento pelo solo (CDE). Foram realizadas coletas de amostras de solo e de dez indivíduos da macrófitas aquática Typha domingensis, em duas parcelas da área de estudo, denominadas PC-01 e PC-02, para a análise de metais pesados. Ainda como parte integrante da avaliação ambiental dessa área, realizou-se o estudo da densidade e diversidade de isópodes terrestres. Considerando as dez campanhas de amostragem realizadas entre agosto de 2012 e fevereiro de 2013, entre a entrada de efluentes pelas fontes pontuais FP-31, FP-32, FP-31A e FP-50 e o canal de drenagem de efluente (CDE), foi verificada uma redução média de 85,5% na vazão, de 50% na DBO5,20, de 76,97% de sólidos totais, 91,22% de sólidos em suspensão, 99,8588% de coliformes totais, 99,9623% de E. coli. Com base nos resultados obtidos, foi verificado que ocorre o processo de atenuação natural de matéria orgânica carbonácea, coliformes totais, Escherichia coli e fosfato na área. Entretanto, devido à constatação de que ocorre o transporte de contaminantes nos perfis vertical e horizontal do solo, atingindo as águas superficiais e as águas subterrâneas, devem ser tomadas medidas para melhoria dos sistemas de tratamento de efluentes na UFSM. Foi constatada a contaminação do solo pelos metais pesados bário, cobre e zinco acima das concentrações limites definidas pela Resolução CONAMA n. 420/2009. Também se verificou a presença de metais pesados no tecido vegetal da macrófita aquática Typha domingensis. Foi verificada a diversidade e a densidade de isópodes do solo que podem ser bioacumuladores de metais pesados. As espécies identificadas foram Oniscus asellus, que pode ser um organismo bioacumulador de metais pesados, e Philoscia muscurum, que pode ser um bioindicador da contaminação pelo lançamento de efluentes na área.

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Quadros, Aline Ferreira de. « Ecologia populacional, estratégias reprodutivas e uso de recursos por isópodos terrestres neotropicais (Crustacea, isopoda) ». reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2009. http://hdl.handle.net/10183/17057.

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Os isópodos terrestres (Crustacea, Oniscidea) apresentam adaptações únicas à vida terrestre, tanto fisiológicas quanto morfológicas e comportamentais. Habitam uma grande variedade de ambientes e são facilmente capturados e mantidos em laboratório, constituindo assim um ótimo modelo para investigações que contribuam para um melhor entendimento da ecologia de solo. Apesar de sua grande importância para o funcionamento dos ecossistemas através da detritivoria e da posição chave que ocupam nas teias tróficas, pouco se sabe sobre a ecologia dos oniscídeos Neotropicais. Neste estudo, foram conduzidos estudos comparativos, relativos à ecologia populacional, estratégias reprodutivas e padrões de atividade das duas espécies de isópodos mais abundantes e representativas do sul do Brasil, Atlantoscia floridana (van Name, 1940) (Philosciidae) e Balloniscus glaber Araujo & Zardo, 1995 (Balloniscidae). Foram comparadas também as preferências alimentares dessas espécies em relação a duas espécies paleárticas, visando propor um modelo para as preferências alimentares dos isópodos. Os estudos relativos à ecologia populacional foram conduzidos no Parque Estadual de Itapuã, no Rio Grande do Sul, Brasil. Após amostragens de maio de 2004 a abril de 2005, 3748 indivíduos foram capturados, correspondendo a seis espécies: B. glaber, A. floridana, Pseudodiploexochus tabularis (Barnard, 1932)(Armadillidae), Trichorhina sp. (Platyarthridae), Alboscia itapuensis Araujo & Quadros 2005 (Philosciidae) e Novamundoniscus gracilis Lopes & Araujo, 2003 (Dubioniscidae). A densidade média foi de 368 ind. m-². Entre estas espécies, A. floridana e B. glaber foram as mais abundantes e mostraram alta associação espacial, com 88% dos seus indivíduos ocorrendo juntos e de forma agregada. A biomassa destas duas espécies foi de 4,92 kg ha-¹ (B. glaber) e 0,97 kg ha-¹ (A. floridana). Foi estimado que as duas espécies juntas são capazes de processar 860 kg folhas ha-¹ ano-¹, correspondendo à 16% do aporte anual de folhas na serapilheira. A densidade média de A. floridana foi 114 ind. m-² e de B. glaber foi 133 ind.m-². Em relação à ecologia populacional, verificamos diferenças entre as espécies. Enquanto as fêmeas reprodutivas de A. floridana estiveram presentes o ano inteiro, B. glaber mostrou um período reprodutivo mais curto e restrito ao verão e primavera. As duas espécies mostraram alta abundância de fêmeas reprodutivas e mancas na primavera. As populações responderam de forma diferente à seca observada no verão de 2005. As análises das características de história de vida e das tabelas de vida e fecundidade mostraram que as espécies têm estratégias reprodutivas distintas: A. floridana apresenta menor longevidade e desenvolvimento mais rápido, começa a se reproduzir mais cedo, mostra menor investimento parental, maior taxa reprodutiva líquida (R 0 ), maior taxa de crescimento (r) e menor tempo de geração (T) em comparação com B. glaber. Estas estratégias de história de vida foram interpretadas sob as predições da teoria r-K e relações dessas predições e o grau de especialização de uso de hábitat. O maior tamanho corporal, presença de pulmões pleopodais e comportamento escavador parecem conferir a B. glaber uma maior tolerância à dessecação e maior sobrevivência de seus jovens e adultos durante condições climáticas adversas É proposto que a reprodução contínua, curto tempo de geração e alta proporção de fêmeas reprodutivas são respostas de A. floridana à alta mortalidade das suas formas jovens. Em laboratório, o padrão de atividade diário foi investigado em relação à susceptibilidade à dessecação, influência de heterospecíficos no comportamento, frequência das atividades e escolha de hábitat para descanso. Foi verificado que B. glaber tem maior atividade durante a noite e A. floridana tem um padrão bem variável, o qual não é restrito à fase escura. Devido a essa variabilidade, a sua atividade se sobrepõe à atividade de B. glaber, o que leva à rejeição da hipótese de que há partição de tempo entre as espécies. Entretanto, parece haver partição de hábitat através de diferenças dos hábitos de descanso. Observações prévias de que B. glaber se enterra no solo durante esse período foram confirmadas. A ausência de interações agressivas entre as duas espécies e a partição de hábitat ajudam a explicar a alta sobreposição espacial e distribuição agregada que as espécies apresentam. As duas espécies mostraram a mesma preferência alimentar, a qual foi também similar à de duas espécies de isópodos paleárticos Porcellio scaber Latreille, 1804 (Porcellionidae) e Philoscia muscorum (Scopoli, 1763)(Philosciidae). Para concluir, é proposto que isópodos terrestres neotropicais e paleárticos preferem se alimentar de folhas que apresentam uma combinação de altos teores de nitrogênio (>2 %) e cálcio (>1 %) e pouca espessura (<0.1 mm). Muitas propriedades definem os alimentos que são rejeitados, entre elas a presença de tricomas e dureza excessiva (>50 g mm-²). Estes resultados devem auxiliar a formulação de hipóteses sobre as taxas de decomposição e fluxos de energia na presença destes detritívoros.
Terrestrial isopods (Crustacea, Oniscidea) present unique physiological, behavioral and morphological adaptations to the terrestrial life. They inhabit a large variety of environments and are easily captured and maintained in laboratory, constituting suitable models for studies towards a better understanding of soil ecology. In spite of the key position they occupy in soil food webs as detritivores, almost nothing is known about the ecology of Neotropical species. The present study describes and compares the population ecology, reproductive strategies and activity patterns of the two most abundant and representative species in southern Brazil, Atlantoscia floridana (van Name, 1940) (Philosciidae) and Balloniscus glaber Araujo & Zardo, 1995 (Balloniscidae). Moreover, their feeding preferences were compared to that of paleartic species aiming the proposal of a template for isopod food choices. All population relates studies were conducted at Parque Estadual de Itapuã, Rio Grande do Sul, southern Brazil. After monthly samplings, from May 2004 to April 2005, 3748 individuals were obtained, comprising six species: B. glaber, A. floridana, Pseudodiploexochus tabularis (Barnard, 1932)(Amadillidae), Trichorhina sp. (Platyarthridae), Alboscia itapuensis Araujo & Quadros, 2005 (Philosciidae) and Novamundoniscus gracilis Lopes & Araujo, 2003 (Dubioniscidae). Total isopod density averaged 368 ind. m-². Among these species, A. floridana and B. glaber where the most abundant and showed a high spatial association, with 88% of their individuals occurring together and in an aggregated distribution. Their biomass averaged 4.92 kg ha-¹ B. glaber and 0.97 kg ha-¹ for A. floridana. It was estimated that together they could process 860 kg leaves ha-¹ year-¹, which corresponds to 16% of the annual leaf litter input. Mean density of A. floridana was 114 ind. m-² and B. glaber's was 133 ind. m-². Regarding their population ecology, we found conspicuous differences between species. Atlantoscia floridana reproductive females were present throughout the entire year, while B. glaber showed a shorter reproduction period, from early spring to early autumn. Both species showed high numbers of reproductive females and mancas during spring. Populations responded differently to the increased dryness observed in the summer of 2005. Analyzes of life history traits and life tables showed contrasting strategies: A. floridana showed a shorter lifetime, faster development, earlier reproduction, a smaller parental investment, higher net reproductive rate (R 0 ), a higher growth rate (r) and a shorter generation time (T) in comparison to B. glaber. These life history strategies were interpreted under the predictions of the r-K selection theory and the relationship between its predictions and the degree of habitat specialization. The larger body size, presence of pleopodal lungs and the burrowing behavior seems to confer to B. glaber a higher tolerance to desiccation and increased young and adult survival under stressful climatic conditions. It is postulated that the continuous reproduction, shorter generation time and higher proportion of reproductive females of A. floridana are responses to its high juvenile mortality. Whereas B. glaber has a very narrow geographic distribution, A. floridana seems to be a successful colonizer, and this success is in part explained by its high reproductive output. These characteristics explain its abundance and commonness. In laboratory, their activity patterns were investigated in relation to differences in susceptibility to desiccation, influence of heterospecifics in behavior, frequency of activities and choice of habitats for resting. Balloniscus glaber has a higher activity during the night while A. floridana has a highly variable activity pattern, not restricted to the dark phase. Due to this variability, its activity mostly overlaps B. glaber's and thus the possibility of time partitioning was rejected. Instead, habitat partitioning through differences in shelter behavior may contribute to decrease species' niche overlap. Previous observations that B. glaber burrows into the soil for resting were confirmed. Both species showed the same preferences when offered a choice of food and preferences rank were also similar to that of paleartic isopods Porcellio scaber Latreille, 1804 (Porcellionidae) and Philoscia muscorum (Scopoli, 1763) (Philosciidae). To conclude, it is suggested that both paleartic and neotropical species prefer to feed from leaves that have a combination of high amount of nitrogen (>2 %) and calcium (>1 %) and low thickness (<0.1 mm). Many properties define the rejected food types, including trichomes and excessive toughness (> 50 g mm-²). These findings may help formulate predictions about decomposition rates and energy flow in the presence of these detritivores.

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Ara?jo, Gustavo Soares de. « ?Ecologia parasit?ria de is?podos e biologia reprodutiva em tibiro, Oligoplites spp (Osteichthyes : carangidae) das ?guas costeiras de Natal, Rio Grande do Norte ». Universidade Federal do Rio Grande do Norte, 2008. http://repositorio.ufrn.br:8080/jspui/handle/123456789/13039.

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Made available in DSpace on 2014-12-17T14:10:16Z (GMT). No. of bitstreams: 1 GustavoSA.pdf: 4369904 bytes, checksum: 083c60d4ddf64c0281449771173dade6 (MD5) Previous issue date: 2008-02-28
Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior
?Oligoplites palometa (Cuvier) and Oligoplites saurus (Bloch & Schneider) (Osteichthyes: Carangidae) are coastal pelagic fish species. The objective of this study was to investigate the effect of parasitism by isopods and the reproductive biology of the leather jack, Oligoplites spp. A total of 113 individuals of Oligoplites spp (35 of O. saurus and 78 of O. palometa) were captured during the period between January, 2005 and July, 2007 from the coastal waters of Natal, RN. The morphometric and meristic characters were registered; macroscopic analyses were done to collect the isopod parasites and the gonads were observed to verify the reproductive aspects. The crustacean isopod parasite, Cymothoa spinipalpa (Isopoda: Cymothidae) was encountered on the tongue in the oral cavity in both fish hosts. The parasitic indices of C. spinipalpa showed high values of prevalance of 51,4% for O. saurus and 64,1% for O. palometa. The host presented significant correlations between body mass and body length of O. palometa and the number of parasites. Body lengths of female C. spinipalpa were small due to the limited space available in the oral cavity of the host. There was a significant difference in the sex ratio of O. palometa, males outnumbered the females. The isopod parasites showed specificity to the oral cavity of hosts. Macroscopic analyses of gonads showed four stages of gonadal development for both sex of O. palometa: immature, maturing, mature and spent
?As esp?cies Oligoplites palometa (Cuvier) e Oligoplites saurus (Bloch & Schneider) (Osteichthyes: Carangidae) s?o peixes costeiros pel?gicos. O objetivo do presente trabalho foi estudar o parasitismo por is?podos e a biologia reprodutiva em tibiro, Oligoplites spp. Foram capturados cento e treze exemplares de Oligoplites spp durante o per?odo de janeiro de 2005 a julho de 2007 nas ?guas costeiras de Natal, RN. Foram realizadas as medidas morfom?tricas e mer?sticas, a an?lise macrosc?pica para coleta dos parasitos is?podos e a retirada das g?nadas para o estudo dos aspectos reprodutivos. Foi encontrada uma nova esp?cie de ectoparasito, Cymothoa spinipalpa (Isopoda: Cymothidae), sobre a l?ngua na cavidade oral em ambas as esp?cies de Oligoplites. Os ?ndices parasit?rios de C. spinipalpa indicaram uma alta preval?ncia sendo de 51,4% para O. saurus e de 64,1% para O. palometa. Em O. palometa existe uma correla??o significativa entre peso do hospedeiro e o n?mero de parasito como tamb?m entre o comprimento total do hospedeiro e o n?mero de parasito. As f?meas de C. spinipalpa tiveram seu comprimento limitado pelo ambiente f?sico dispon?vel na cavidade bucal do hospedeiro. Foi encontrada uma diferen?a significativa na propor??o sexual de O. palometa, com um maior n?mero de machos em rela??o ao n?mero de f?meas. Os is?podos t?m especificidade pela cavidade oral dos hospedeiros. A an?lise macrosc?pica das g?nadas permitiu a identifica??o de quatro est?dios distintos de matura??o em ambos os sexos de O. palometa: imaturo, em matura??o, maduro e esvaziado

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Bredon, Marius. « Caractérisation de l'holobionte des isopodes par des approches omiques : exemple du processus de dégradation de la lignocellulose ». Thesis, Poitiers, 2019. http://www.theses.fr/2019POIT2318.

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Les isopodes représentent un modèle de choix pour l’étude des interactions au sein de l’holobionte car ils hébergent un microbiote riche et diversifié, dont la composition est très variable, sous la dépendance de l’environnement et des traits d’histoire de vie de l’hôte. Certains de leurs endosymbiotes tels que la bactérie féminisante Wolbachia et leurs conséquences sur la trajectoire évolutive des hôtes ont été bien caractérisés. Une perspective plus globale des interactions au sein de l’holobionte et leurs impacts sur la valeur adaptative de l’hôte n’a été que peu envisagée. Dans ce cadre, nous avons utilisé une combinaison d’approches expérimentales, de métagénomique, de transcriptomique et d’analyse de l’expression de gènes, afin de mieux comprendre les mécanismes et les conséquences de ces interactions sur la valeur adaptative de l’hôte. Dans un premier temps, cette thèse explore les interactions hôtes-microbiotes au travers du processus de dégradation de la lignocellulose, essentiel dans la nutrition des isopodes. Le répertoire enzymatique lié à la dégradation de la lignocellulose de l’hôte et du microbiote du cloporte Armadillidium vulgare ont été identifiés. La comparaison de ces deux répertoires enzymatiques a permis de mettre en évidence leur complémentarité, suggérant ainsi une étroite collaboration entre l’hôte et son microbiote pour la dégradation de la lignocellulose. La contribution de l’hôte et de son microbiote dans ce processus a ensuite été quantifiée en fonction de plusieurs régimes alimentaires avec des approches de métabarcoding et d’expression de gènes de CAZymes, enzymes spécialisées dans la dégradation de la lignocellulose. Dans un second temps, l’identification du répertoire de CAZymes dans 64 transcriptomes d’isopodes aquatiques et terrestres a permis d’apporter de nouveaux éléments sur les processus évolutifs qui ont favorisé la conquête des écosystèmes terrestres par les isopodes. Ces travaux ont été approfondis par l’obtention des métagénomes de cinq espèces d’isopodes permettant de caractériser les stratégies de déconstruction de la lignocellulose dans l’holobionte. La reconstruction des génomes bactériens à partir des métagénomes a permis d’identifier d’autres symbiotes chez les isopodes. Nous avons parallèlement caractérisé un premier virome des isopodes, qui montre que les phages constituent une part importante du microbiote. Ils pourraient jouer un rôle crucial comme régulateurs des communautés bactériennes au sein de l’holobionte. L’ensemble de ces travaux illustre la richesse des interactions entre le microbiote et l’hôte chez les isopodes pour la dégradation de la lignocellulose, et ouvre la voie à de nouvelles implications du microbiote au sein de l’holobionte des isopodes
Isopods are good models to study interactions within the holobiont because they host a rich and diversified microbiota, whose composition is highly variable, depending on the environment and the host's life history traits. Some of their endosymbionts such as the feminizing bacteria Wolbachia, and their consequences on the evolutionary trajectory of hosts have been well characterised. A more global perspective of interactions within the holobiont and their impacts on the host’s fitness has been little considered. In this context, we used a combination of metagenomics, transcriptomics and gene expression analysis approaches to better understand the mechanisms and consequences of these interactions on the host's fitness. First, this thesis explores host-microbial interactions through the lignocellulose degradation process, which is essential for isopods’ nutrition. The host and microbiota’s enzymatic repertoires related to the degradation of lignocellulose have been identified in the woodlouse Armadillidium vulgare. The comparison of these two enzyme repertoires revealed their complementarity, suggesting a close collaboration between the host and its microbiota for lignocellulose degradation. The contribution of the host and its microbiota to this process was then quantified according to several diets with gene expression of CAZymes (enzymes specialized in lignocellulose degradation) and metabarcoding approaches. Secondly, the identification of the CAZymes repertoire in 64 transcriptomes of aquatic and terrestrial isopods provided new information on the evolutionary processes that have favoured the conquest of lands by isopods. This work was further developed by obtaining metagenomes of five isopod species to characterise lignocellulose deconstruction strategies in the holobiont. The reconstruction of bacterial genomes from metagenomes enabled us to identify other symbionts in isopods. We also have characterised a first virome of isopods, which shows that phages constitute an important part of the microbiota. They could play a crucial role as regulators of bacterial communities within the holobiont. All these studies illustrate the richness of interactions between the microbiota and the host in isopods for lignocellulose degradation, and open the way to new implications of the microbiota within the isopods’ holobiont

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Francois, Clémentine. « Évaluation des stratégies adaptatives des métazoaires aux faibles disponibilités en nutriments : couplage d’approches d’écologie isotopique et de transcriptomique chez des isopodes épigés et hypogés ». Thesis, Lyon 1, 2015. http://www.theses.fr/2015LYO10140/document.

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L'objectif de cette thèse est d'étudier les réponses adaptatives des métazoaires à une diminution de la disponibilité en nutriments dans leur environnement. Ce travail, couplant des approches d'écologie isotopique et de transcriptomique, est basé sur l'analyse comparative d'isopodes de surface (épigés) et souterrains (hypogés) évoluant depuis plusieurs millions d'années dans des environnements présentant des disponibilités en nutriments très contrastées (absence de photosynthèse en milieu souterrain). Leur histoire évolutive (multiples colonisations indépendantes du milieu souterrain) a permis de définir 13 couples composés d'une espèce épigée et d'une espèce hypogée partageant un ancêtre commun épigé (i.e. 13 réplicats indépendants d'une transition vers un milieu plus pauvre en nutriments). Des adaptations en termes d'amélioration de l'acquisition des nutriments (diminution de la sélectivité trophique, stratégies spécialistes) et de diminution de la demande métabolique (diminution du taux de croissance) ont été mises en évidence chez les isopodes hypogés. En revanche, l'hypothèse d'une sélection _stoechiogénomique_ des nucléotides et acides aminés les plus économes en azote a été réfutée. Il est possible que la sélection naturelle soit inopérante sur la composition des ARN et protéines de par les faibles tailles efficaces de population (Ne) des métazoaires. La sélection pourrait aussi être inexistante à ce niveau, de par l'existence d'interactions entre les différentes réponses adaptatives. Ainsi, l'adoption de certaines réponses adaptatives plus efficaces et/ou rapides à mettre en place pourrait suffire à relâcher la pression de sélection sur les autres réponses
The aim of this PhD project was to investigate the adaptive responses of metazoan to a decrease of nutrient availabilities in their environment.We combined isotopic ecology and Next-Generation Sequencing in a comparative analysis of surface (epigean) and groundwater (hypogean) isopods living in highly contrasted environments in terms of nutrient availabilities (lack of photosynthetic production in groundwater). The original evolutionary history of these isopods (multiple independent colonizations of the subterranean habitat) enabled to define 13 species pairs composed of one epigean and one hypogean species sharing a common epigean ancestor. Using these pairs, we studied 13 independent replicates of an environmental transition towards very low nutrient availabilities. Hypogean isopods display adaptations improving the nutrient acquisition (specialist strategy, decrease of trophic selectivity) as well as adaptations reducing the metabolic needs of organisms (decrease of growth rate). However, hypogean isopods do not display adaptive changes in their macromolecules composition (no evidence for the ’stoichiogenomic’ selection of N-thrifty nucleotides and amino acids). Because of the small effective population size (Ne) of metazoa, natural selection may be inefficient to select N-sparing responses at the level of RNA and protein composition. Selection could also be inexistent at this level in case of interactions between the different adaptive responses. Indeed, some nutrientsaving mechanisms may have been selected more quickly or more efficiently, these adaptations being sufficient to relax the selective pressure on the other response levels

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Herran, Benjamin. « La voie de signalisation type insuline dans la différenciation sexuelle chez les Crustacés isopodes - intégration de l'hormone androgène et de facteurs féminisants dans un nouveau contexte ». Thesis, Poitiers, 2018. http://www.theses.fr/2018POIT2310.

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La différenciation sexuelle des Isopodes dépend d'une hormone sexuelle protéique, l'hormone androgène (HA), caractéristique des Malacostracés. Cet Insulin-Like Peptide suffit à induire par sa présence la différenciation mâle de ces Crustacés. Nous avons identifié in silico le transporteur circulant de l'HA, l'IGFBP-rP1, chez de nombreuses espèces d'Isopodes ainsi qu'à l'échelle des Crustacés. De la même façon, nous avons identifié deux récepteurs transmembranaires, l'IR1 et l'IR2, issus d'une duplication de gène spécifique des Malacostracés. Les patrons d'expression de ces gènes ont été étudiés sur notre espèce modèle, Armadillidium vulgare. Av-IGFBP-rP1 et Av-IR1 sont exprimés de manière ubiquiste et tout au long du développement. Av-IR2 est aussi exprimé à chaque stade de la différenciation mais ce transcrit est quasi-spécifique des glandes androgènes et ovaires. Une approche par ARNi a confirmé l'implication de ces trois protéines dans la voie de signalisation de l'HA. En effet, l'inhibition de l'HA, Av-IGFBP-rP1 et Av-IR1 provoquent l'hypertrophie des glandes androgènes, suggérant leur implication dans une boucle de rétro-contrôle de l'HA. L'inhibition de Av-IR2 semble seulement provoquer la différenciation d'ouvertures génitales femelles. Ces phénotypes sont comparables à ceux des intersexués mâles induits par la bactérie féminisante endogène Wolbachia. Nous montrons cependant que la bactérie altère seulement l'expression de l'HA et pas celle des récepteurs. Enfin, nous avons testé l'effet du bisphénol A mais nous n'observons pas d'altération de la différenciation sexuelle des larves lors d'expositions à ce perturbateur endocrinien exogène
Sexual differentiation in Isopods relies on a proteinaceous sex hormone called androgenic hormone (AH), specific to Malacostracans. This Insulin-Like Peptide induces male differentiation by its mere presence in these Crustaceans. We identified in silico the circulating carrier of the AH, called IGFBP-rP1, in many Isopod species, but also on the crustacean scale. Similarly, we identified two transmembrane receptors, IR1 and IR2, coming from a gene duplication specific to Malacostracans. The expression patterns of these genes were investigated in our model species, Armadillidium vulgare. Av-IGFBP-rP1 and Av-IR1 are broadly expressed in the animal and throughout development. Av-IR2 is also expressed at each developmental stage but this transcript is almost specific to androgenic glands and ovaries. An RNAi approach has confirmed the implication of these three proteins in the AH signalling pathway. Indeed, the inhibition of AH, Av-IGFBP-rP1 and Av-IR1 induces androgenic gland hypertrophy, suggesting their implication in an AH feedback loop. Av-IR2 inhibition seems to provoke the differentiation of female genital apertures only. These phenotypes are similar to those of male intersexes induced by the endogenous feminizing bacterium Wolbachia. Yet, we show that the bacterium alters the expression of the AH only and not the one of its receptors. Finally, we have tested the effect of bisphenol A but we observe no alteration of the sexual differentiation in larvae upon exposition to this exogenous endocrine disruptor

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Farquharson, Charon. « Biodiversity of the fish parasitic Gnathiid isopods from coral reefs ». Thesis, 2011. http://hdl.handle.net/10210/3726.

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M.Sc.
Recent years have seen a remarkable increase in scientific research and studies conducted regarding the unique group of parasitic isopods known as gnathiids. The taxonomy of gnathiids are based solely on the morphological characteristics of the free-living adult males, which means that the female and larval life stages are often not collected and described with the males, and when collected it is seldom possible to even identify these stages when not in the company of there adult males. Numerous studies have been conducted in Australia regarding cleaning behaviour of coral reef fishes, where these gnathiid larvae are extremely abundant and are often collected. These types of studies as well as others are increasing all around the world, and because of the fact that the larvae cannot be easily identified, the results and data collected from these various studies are often misinterpreted or inconclusive and makes no sense. The fact that gnathiid larvae may serve as possible vectors for certain fish blood parasites and have various physiological and ecological effects on their fish hosts, which may lead to mortality, can have detrimental economical effects on the fisheries industry. This study was thus conducted to improve the identification methods that are currently applied to the larval life stages of gnathiid isopods through various means including increasing the number of detailed descriptions available, constructing a taxonomic key and lastly conducting a basic phylogenetic analysis of a group of known gnathiid larvae in order to aid researchers with future identifications. It was hypothesised that firstly, although there are some gnathiid descriptions from coral reefs, mostly of adult males, it is likely that there are still a great number of unknown and not yet described gnathiid species, because coral reefs are one of the most highly biodiverse marine ecosystems. Secondly, that the distribution of coral reef gnathiids is much wider than currently known or documented and lastly, that it might be possible to identify gnathiid larvae species in the absence of adult males, through the use of detailed taxonomic descriptions of these larval stages and there live colouration patterns, and to then construct a taxonomic key to aid researchers with future identifications.

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Μουζάκης, Δημήτριος. « Πρώτη προσέγγιση της αναπαραγωγικής βιολογίας του χερσόβιου ισόποδου Armadillidium lobocurvum Verhoeff, 1902 σε ανωδασικά οικοσυστήματα του όρους Παναχαϊκού ». Thesis, 2007. http://nemertes.lis.upatras.gr/jspui/handle/10889/1007.

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45

Liu, Shuang. « Phylogeographic Patterns of the Intertidal Isopods Excirolana braziliensis and Excirolana mayana (Isopoda : Cirolanidae) ». Thesis, 2013. http://hdl.handle.net/1969.1/149336.

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Cryptic species complexes are common in many marine groups. Recent phylogeographic studies in the megadiverse Gulf of California basin have found high levels of cryptic allopatric genetic differentiation in supralittoral isopods. Long standing isolation among populations of these isopods appears to stem from biological characteristics that severely limit their dispersal potential, such as direct development (i.e., lacking a larval stage), as well as a strong association to specific intertidal patchy habitats. Studies of other intertidal isopods have the potential to reveal high levels of cryptic allopatric genetic differentiation. This study examined phylogeographic patterns of intertidal isopods of the genus Excirolana distributed in the Gulf of California. Adults of these isopods are distributed at the highest tidal levels, and phylogeographic studies of Excirolana in Panama and Chile have shown restricted gene flow among populations separated by relatively short distances. Excirolana samples were collected across the Gulf of California, as well as from the Atlantic and Pacific coasts of South and Central America, and from several Caribbean islands; encompassing most of the geographic range for the Excirolana species reported in the Gulf of California. Sequences of DNA fragments from four mitochondrial genes were obtained, and phylogenetic analyses with Maximum Likelihood and Bayesian methods were conducted. Diagnostic morphological characteristics were examined to determine whether individuals corresponded with any of the three species reported in the Gulf of California: E. braziliensis; E. mayana; and E. chamensis. Isopods with morphological characteristics of E. braziliensis and E. mayana were found. In general, relatively low genetic diversity was observed within localities. Phylogenetic analyses indicate that samples with the morphology of E. braziliensis formed a well-supported clade, whereas individuals with the E. mayana morphology formed another well-supported clade. Highly divergent lineages were observed within each of these clades, suggesting they represent cryptic species complexes. In the Gulf of California, several regional clades and subclades of Excirolana exhibit similar distributions to those of several clades within the supralittoral isopods Ligia and Tylos. This study allows a better understanding on the phylogenetic relationships, phylogeographic patterns, and diversity of Excirolana in the Gulf of California, and the Americas in general.

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González, Poblete L. « Ectoparasites and associated pathogens affecting farmed salmon during marine grow out in Chile and Australia ». Thesis, 2015. https://eprints.utas.edu.au/22751/1/Gonzalez_Poblete_whole_thesis.pdf.

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This research characterized some outbreaks of the ectoparasite Caligus rogercresseyi in Chile and compared them to similar infestations in Australia by Caligus longirostris and Ceratothoa banksii, in relation to co-infections by piscirickettsiosis and viral infection salmon anaemia (ISA virus (ISAV)) in Chile and/or amoebic gill disease (AGD – both in Australia and Chile), and according to husbandry management practices. Understanding how and why co-infections occur allows the development of preventive integrated strategies. The co-infection of these pathogens could occur because 1) salmon, normally resistant to a pathogen become, more susceptible to it, due to pre-infection with an ectoparasite or vice-versa, and 2) salmon farms have single-pathogen oriented control strategies that are ineffective. To identify the reservoirs for Neoparamoeba perurans (AGD etiological agent) on ectoparasites from farmed salmon in Tasmania, the presence of this amoeba was investigated on the gill isopod Ceratothoa banksii collected from farmed salmon. Using quantitative real-time PCR analysis it was demonstrated that N. perurans was either present in low concentration or absent on the surface, and absent inside the gill isopods from salmon that had not been freshwater bathed for AGD during 200 or more days. Thus it is unlikely that these isopods acted as reservoirs or vectors for the amoeba. In contrast, with the potential advent of alternative (non-freshwater) AGD treatments it is possible that Ceratothoid parasitism will become a potential problem on Tasmanian salmon farms. An investigation of the environmental reservoirs of N. perurans during tank-based experimental infections demonstrated that the concentration of N. perurans was significantly higher in the running water (13 ± 7 cells/L after 16 days) than on the interphase surface air-water-tank (0.01 ±0.1 cells/L). Although the number of N. perurans on fish gills was not determined in this tank-based study, on farmed Atlantic salmon from the Huon estuary chronically affected with AGD, amoebae detected from gill swabs ranged from 0-1042 cells/swab, which could indicate that fish themselves are reservoirs of this pathogen. To characterize the outbreaks of the sea lice with the other main pathogens (N. perurans, Piscirickettsia salmonis and ISAV), moribund salmonids were sampled in Chile in 2011 from two neighboring farms. On one farm, rainbow trout were bath-treated with deltamethrin for sea lice fortnightly in October and November and Atlantic salmon from the other farm treated only after the monitoring on 9 November. Co-infection with P. salmonis was present in 28% of rainbow trout and 10-12% of Atlantic salmon, with asymptomatic ISAV (pathogenic strain HPR 7b) in 17% and 80% of the trout and salmon respectively. Fish had not been treated for sea lice despite having a parasite load exceeding 6 lice per fish which is the load where treatment is mandatory. They also showed microscopically and gross gill damage or excess mucus production. The etiological agent of this gill pathology is still unclear, as fish and sea water from farms were free from N. perurans. Water samples did not contain any significant levels of contaminants, diatoms or dinoflagellates and gill damage was not caused by the chemical baths. Apparently healthy Atlantic salmon sampled in 2013 in a farm in Chile that had been subjected to monthly cypermethrin lice treatments, showed no P. salmonis but 33% of the fish in April and 22% in June, were asymptomatic carriers of the pathogenic strain ISAV (HPR 7b). The routine monitoring mortalities in this farm determined that 2% and 12% died by piscirickttsiosis in April and June respectively. Sea lice abundance was lower in most netpens in April with higher water temperatures and AGD presence compared to June with lower temperatures and without AGD. A diverse level of chronic gill lesions were observed on fish samples such as the undetermined gill pathology on fish in 2011, seasonal AGD in March-April 2013 and multiple mucous cells in June 2013. This gill pathology could be the source of fish mortality during sea louse treatments. It could also cause stress on farmed fish that can promote the fast multiplication of the remaining sea lice on the immunosuppressed farmed fish. This could effectively maintain a chronic infestation. Systematic chemical baths that are compulsory for sea lice treatment in Chile can increase gill damage, they can cause stress and predispose fish to outbreaks of ISA or piscirickettsiosis. A reduction of frequency of chemical baths is advised, particularly considering that in Chile, there are no wild populations of fish that need protection from C. rogercresseyi released from farms. This will also help with the fulfilment of the good practice measures to control sea lice and ISA by the reduction of salmon handling and limited use of chemical therapies. In addition, on farms with piscirickettsiosis outbreaks, the daily removal not only of mortality but particularly of moribund fish is required. In relation to environmental friendly treatments, although freshwater baths for AGD could be an alternative control for sea lice, the location far from estuarine areas of most salmon farms in Chile and the lack of plentiful freshwater indicate difficulties for the implementation of this method.

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Javidkar, Seyedmohammad. « Molecular systematics and biogeographic history of oniscidean isopod troglofauna in groundwater calcretes of Central Western Australia ». Thesis, 2014. http://hdl.handle.net/2440/93518.

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Groundwater calcretes of central Western Australia have revealed an extraordinary diversity of short-range endemic invertebrate subterranean fauna. Although considerable attention has been given to the aquatic dwellers of the calcretes (stygofauna), the subterranean terrestrial fauna of the calcretes (troglofauna), particularly the oniscidean isopods, have been poorly studied. This thesis, including four data chapters, presents the results of multiple-gene and morphological analyses to establish a phylogenetic framework for elucidation of species diversity, systematics, and the biogeographic history of oniscidean isopod troglofauna in arid central Western Australia. The first data chapter focuses on higher level systematic relationships of the isopod fauna. In order to examine the monophyly of the family Platyarthridae, representatives of the main oniscidean families and genera from Australia, South America, Africa and Europe were analysed using molecular and morphological approaches, including data from a Scanning Electron Microscopy study. The phylogenetic analyses of mitochondrial and nuclear genes (COI, 18S, and 28S) showed that Platyarthridae is polyphyletic, and also revealed a very distinct Australian lineage with a unique water conducting system on antenna 2. Based on both morphological and molecular data, a new southern hemisphere oniscidean family, Paraplatyarthridae, occurring from subtropical/temperate to arid regions of Australia and South America, is proposed and described. The second data chapter focuses on the molecular systematics, species diversification and distributional patterns of the oniscidean troglofauna in calcrete aquifers of central Western Australia. The results, based on morphological and multiple-gene molecular approaches, reveal a significant diversity of oniscidean DNA lineages. The application of different species delineation methods, suggests the existence of 28 putative species belonging to four oniscidean families, which most likely represent distinct undescribed species. The phylogenetic analyses show (with some exceptions) that the majority of oniscidean DNA lineages were restricted in their distribution to individual calcrete bodies, lending support to the hypothesis that individual calcretes are equivalent to “Subterranean Islands”. In addition, the occurrence of subtropical, littoral and benthic oniscidean groups in the calcretes suggests complex historical events, including the marine inundation of the Eucla basin during the late Eocene, have shaped the taxonomic representation of the current oniscidean troglofauna. The third data chapter investigates the biogeographic history of the widespread genus Paraplatyarthrus, which showed noticeable morphological diversity, from troglophilic to troglobitic forms. The phylogenetic and molecular clock dating analyses provided evidence that evolutionary transitions from surface to subterranean habitats took place from the late Miocene, and further indicated that troglophile ancestral species independently colonised the calcrete aquifers. These findings support both the climatic relict and adaptive shift hypotheses to explain the evolution of the oniscidean isopod troglofanua with aridity being a significant driver of diversification underground. The final data chapter comprises the morphological description of five new species of the genus Paraplatyarthrus (Paraplatyarthridae fam. nov.) and provides a key to their identification.
Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2014

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Hadfield, Kerry Ann. « The biodiversity and systematics of marine fish parasitic isopods of the family Cymothoidae from Southern Africa ». Thesis, 2012. http://hdl.handle.net/10210/8063.

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Ph.D.
Within the order Isopoda, only a few families are known to be parasitic. Representatives from the family, Cymothoidae, are obligate parasites of both marine and freshwater fishes. In South Africa, information regarding these isopods is scanty and the little that is known is mostly outdated and inaccurate. Currently only 12 species of cymothoid isopods are known from this region and thus it was hypothesised that with proper sampling and identification, this number would increase and that the known number is not a true reflection of the actual number of cymothoid isopods present. A complete revision of the southern African Cymothoidae is required and thus this project focussed on three of the least studied genera, Ceratothoa Dana, 1852, Cinusa Schioedte & Meinert, 1884, and Cymothoa Fabricius, 1787. The cymothoid isopods studied in this project were obtained from fresh collections along the southern African coast as well as from museum collections. The fresh material was obtained from various sampling trips along the east and south coasts of South Africa as well as from Zanzibar, Tanzania. The museum collections were loaned from a number of national and international museums, and preserved isopods were also collected from fish specimens housed in the South African Institute for Aquatic Biodiversity (SAIAB) museum. Isopods were dissected (if possible), drawn and described. Species descriptions were prepared in DELTA (Descriptive Language for Taxonomy) using a specifically constructed Cymothoidae data set. All valid members of the buccal inhabiting genera Ceratothoa, Cinusa and Cymothoa, were completely reviewed including a full account of the species synonymy, distribution, and known hosts as well as a few additional notes. Where applicable, a redescription of the type specimen was also provided and problematic combinations or issues in the species were discussed. Each species was then defined as valid, invalid or of questionable status and a complete reviewed species list for the genus was provided. According to the World Marine, Freshwater and Terrestrial Isopod Crustaceans database, there are 31 accepted Ceratothoa species names. After completion of the Ceratothoa review, eight species were considered questionable and another three were synonymised with other valid species. Thus, the species list was diminished to a total of 20 currently known and valid Ceratothoa species. In South Africa, another two new species were identified and described, which would increase the number of Ceratothoa species in this region to four, and will add another two species onto the world list once published.

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Hsu, Szu-Ting, et 許絲婷. « Relationship Between Soil Salinity and the Distribution of Three Costal Terrestrial Isopods (Isopoda : Oniscidea) in Taiwan ». Thesis, 2013. http://ndltd.ncl.edu.tw/handle/36205325932961004798.

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碩士
國立中山大學
生物科學系研究所
101
The soil abiotic factors such as soil organic matter, water content, and salinity are the important as to affect the habitat selection and distribution of soil invertebrates. The soil organisms inhabiting in coastal zone are affected mostly salinity. In the past, studies on the distribution of organisms were mostly on plants, with few on soil invertebrate. This study aims to investigative three terrestrial isopods in coastal areas in Taiwan, and explore of the relationship between soil salinity and distribution. Alloniscis sp. lives above the high tide line to the coastal wetlands, supposed to have higher salt tolerance compared with other two; Venezillo parvus is widely distributed from coast forest to inland; and Burmoniscus meeusei is common in wet soil inland. The species abundance, soil salinity, water content, and organic matters were recorded in Aogu wetland and Yiwu farm, southern Taiwan. Preference and survival rates of these species under different soil salinity levels were investigated. The results showed that soil salinity and soil water content are important factors affecting the species distribution. Alloniscus sp. prefers the salt marsh and swamp with high soil salinity. The result of survival of the three species under different salinity condition showed that, V. parvus is the most salt tolerant, followed by Alloniscus sp.; with B. meeusei as the last. The soil salinity preference experiment showed that Alloniscus sp. has no special salinity preference; V. parvus is found mostly in salinity of EC = 4-8 mS/cm; and B. meeusei EC = 0-2 mS/cm. Alloniscus sp., the species most close to coastline did not show the highest salt tolerance ability among the three species. The distribution of Alloniscus sp. Might be affected not only by soil salinity, but also by species competition. The high salinity tolerance in V. parvus may be due to its ability to roll its body. B. meeusei has least salinity tolerance and is species which unsuitable living in coastal zone.

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Murillo, Contreras Liliana del Carmen. « Defining ecoregions based on soil invertebrates for defining pesticide exposure scenarios ». Master's thesis, 2011. http://hdl.handle.net/10316/30830.

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Dissertação de Mestrado em Ecologia, apresentada ao Departamento de Ciências da Vida da Faculdade de Ciências e Tecnologia da Universidade de Coimbra
Environmental Risk Assessment (ERA) is a process of identifying and evaluating the adverse effects on the environment caused by a chemical substance. Modeling environmental relevant concentrations in soil (ERCsoil) requires a different approach than the standard exposure scenario. Ecologically relevant scenarios must calculate exposure according to the habitats of soil organisms’ communities, their role in supporting soil functions and allow modeling ERC in different soil layers all around Europe. The aim of this study is to contribute in the definition of a EU-wide ecoregion-based map to improve the ecological relevance of soil exposure scenarios for collembola and isopods. These organisms were selected based on their importance ecological role in European soils, presence in a wide geographical scale, different morphological and ecological characteristics and data availability. Finland, Germany and Portugal were selected as model countries. The European Food Safety Authority (EFSA) databases used for this study compile information from published and some unpublished articles, species catalogs, and regional inventories. European Joint Research Center (JRC) maps provided the missing environmental variables for the spatial analysis. Soil organisms groups were classified by life form: euedaphic, hemiedaphic and epigeic for collembola; soil dwellers and litter dwellers for isopods; and then classified by dominance classes. Life form raw richness was used to create a generalized linear model (GLM) to describe the soil organisms’ distribution and class dominance. The software STELLA was employed to design a Stochastic Dynamic Methodology (StDM) model to predict distribution of the target soil groups. The results of the GLM and StDM model simulations were incorporated in ArcView 9.2 using the spatial analyst and geostatistical analysis extensions. The raster calculator and Ordinary Kriging were chosen to produce raw richness distribution maps for all life forms of collembola and isopods and to map class dominance. The models were not very successful at predicting low frequencies of dominance classes. Regardless, they were in line with ecological and biogeographic information for the considered groups. For collembola, Finland was dominated by epigeic species, while Portugal showed a dominance of epigeic and hemiedaphic species. In the case of Germany, the analysis methods reached different conclusions and patterns, the raster calculator analysis showed clear epigeic dominance while the ordinary kriging map displayed epigeic and hemiedaphic dominance. For isopods, both methodologies produced similar values for the two life forms in all countries, on average from 0 to 50% for soil dwellers and from 50 to 100% for litter dwellers. The only worst-case scenario predicted for pesticide assessment in all three countries was litter to 1 cm. Overall, the results obtained from the spatial and the geostatistical analysts were not helpful to define ecoregions for pesticide risk assessment given the available data and the selected GLM variables, as they do not provide enough discrimination between worstcase scenarios. Future studies should consider including only site data with complete environmental variables information and a specified geographical location. Abundance would also be a welcome improvement to the model.

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