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1
Englund, Göran. "Competition in caddis larvae". Doctoral thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 1992. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-101356.
Testo completoAbstract (sommario):
This thesis deals with behavioural strategies used by caddis larvae in pairwise contests and when selecting microhabitats. Effects of caddis larvae on survival and habitat selection of other insect taxa have also been studied. The behaviours used by Arctopsyche ladogensis larvae fighting for nets, and Agrypnia pagetana larvae fighting for cases, agreed well with predictions from the sequential assessment game, which is an ESS model of animal fighting behaviour. Establishment by net-spinning Hydropsyche siltalai larvae on artificial substrates was highest at intermediate densities of residents. Emigration/mortality was density independent, and it was higher at a poor site (low food availability) than at a rich site. Establishment was unaffected by site quality. Growth was density dependent because larvae in upstream positions reduced both current velocity and concentration of food particles for larvae in downstream positions. A field experiment involved manipulations of the density of H. siltalai larvae and their nets in a lake outlet stream. H. siltalai larvae affected all abundant taxa, but the mechanism involved varied between taxa. Rhyacophila nubila (Trichoptera) and chironomid larvae benefited from the presence of H. siltalai nets. Negative effects on nymphs of the mayfly Ephemerella ignita were due to predation by H. siltalai larvae, while a combination of predation and increased emigration in response to nets depressed densities of Simulium truncatum blackfly larvae.Diss. (sammanfattning) Umeå : Umeå universitet, 1992, härtill 5 uppsatser
digitalisering@umu
2
Fulmore, Helena Sasha. "Desperate Coral Larvae? Behavioral Responses to Settlement Cues in Aging Agaricia agaricites Larvae". Thesis, NSUWorks, 2019. https://nsuworks.nova.edu/occ_stuetd/519.
Testo completoAbstract (sommario):
The global stressors of ocean warming and acidification, as well as local stressors such as eutrophication, overfishing, and coastal construction, have all contributed to the severe decline in coral populations worldwide. Recovery of coral reefs depends partly on recruitment, which relies on the response of larvae to settlement cues indicative of habitat quality; however, it remains unclear whether recruitment in disturbed areas will be compromised. Specifically, as reefs become more disturbed and dominated by macroalgae, it is important to understand larval behavior in response to changes in habitat quality. In this study, we first assessed the settlement success of newly released Agaricia agariciteslarvae in response to several settlement cues, including temperature and water movement. Then, to test the Desperate Larva Hypothesis, the ability of larvae of different ages (0-7 days) to settle and discriminate between inducing and inhibitory settlement cues was assessed. Newly released larvae displayed a stronger preference for settling on crustose coralline algae (93%) than on ceramic plates in macroalgae- (30%) or conspecific-treated seawater (5%), or filtered seawater (13%) (control). Older larvae became progressively less discriminatory of settlement cues, settling even in response to inhibitory cues. This confirms that, although the absence of good settlement cues initially deters settlement, larvae become desperate as they become older and settle even on unfavorable substrates, thus contributing to recruitment in poor quality habitats.
3
Greenfield, Bethany Patricia Jane. "Metarhizium pathogenesis of mosquito larvae". Thesis, Swansea University, 2014. https://cronfa.swan.ac.uk/Record/cronfa42819.
Testo completo
4
DiBacco, Claudio. "Bay-ocean exchange of crab larvae : the roles of larval behavior, origins, distribution and physical processes /". Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2002. http://wwwlib.umi.com/cr/ucsd/fullcit?p3035924.
Testo completo
5
Lindley, John Alistair. "Spatio-temporal distributions of pelagic larvae and post-larvae of decapod crustacea in seas around Britain". Thesis, University of Plymouth, 1998. http://hdl.handle.net/10026.1/2464.
Testo completoAbstract (sommario):
The geographical distributions and seasonal occurrences of decapod larvae and pelagic post-larvae in continuous plankton recorder (CPR) samples over a 3-year period were analysed and described. During this period, the survey covered large areas of the north-eastern Atlantic Ocean and adjacent continental shelf waters, including the English Channel and the North, Irish and Celtic Seas. Multivariate analysis provided the basis for classifying the distributions of 36 of the most abundant taxa (species, genera or subfamily) into groups. These groupings demonstrated the significance of bathymetry and temperature in limiting distributions. Larvae of 3 species were shown to disperse during development from areas where the earliest larvae occurred into areas that were presumably unsuitable for successful reproduction. Geographical variations in the seasonal timing of occurrence in the plankton of larvae of benthic decapods were correlated with parameters of temperature. Analysis of decapods from CPR samples in a subsequent anomalously warm year ( 1989) demonstrated that these correlations also applied to interannual variations within areas. Samples taken using the Longhurst-Hardy Plankton Recorder (LHPR) were analysed to describe vertical distributions of pelagic stages of decapods. Stratification of temperature, salinity and abundance of chlorophyll influenced the vertical distributions and die migrations of decapod larvae. The nature and extent of that influence varied between taxa. For example Pagurus bernhardus zoeas were concentrated near the surface around the thermocline or below the thermocline according to conditions but Liocarcinus spp. zoeas were most abundant above or at the thermocline in all the profiles in which they occurred. Where ontogenetic variation was observed, later developmental stages generally occurred at greater depth than earlier stages. Some of the observed features of vertical distributions were consistent with aspects of results from the single depth CPR samples. The lengths of carapaces of specimens sorted live from the plankton were measured and dry weights, carbon content and nitrogen content of individual larvae were determined. Regressions of dry weight on carapace length, carbon weight on dry weight and nitrogen weight on dry weight were calculated and found to be comparable in most cases with published data on laboratory reared larvae. Regressions of development times on temperature for each stage of selected taxa with fixed numbers of developmental stages were derived from the literature. A method was developed for estimating biomass and production of planktonic larvae, including fluxes between the benthos and plankton at hatching and settlement, from the results of plankton surveys using the regressions of dry weight on carapace length and development times on temperature. Decapoda usually comprised 1-8% of the dry weight biomass of zooplankton retained by a 200µm mesh from samples in the Irish Sea and North Sea in the spring.
6
Johnson, Kevin Brett. "Predation on planktonic marine invertebrate larvae". Thesis, Thesis (Ph. D.)--University of Oregon, 1998, 1998. http://hdl.handle.net/1794/10086.
Testo completo
7
Silva, Najara da [UNESP]. "Caracterização molecular e expressão de aminopeptidase (APNs) de Ostrinia nubilalis HÜBER 1796 (Lepidoptera: Crambidae)". Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/108433.
Testo completoAbstract (sommario):
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000738502.pdf: 1467766 bytes, checksum: 7c0de265290f7067173746101d9a2b71 (MD5)Aminopeptidases N (APNs) são uma classe de ectoenzimas presentes no intestino médio das larvas de lepidópteros, que participa no cenário do modo de ação das toxinas Bacillus thuringiensis (Bt). No presente trabalho, duas aminopeptidases (OnAPN5 e OnAPN6) foram clonadas a partir células do intestino de Ostrinia nubilalis, lepidópteros praga do milho dos climas temperados. As duas sequências foram identificadas como APNs pela da presença dos motivos HEXXH18(X)E e GAMEM, bem como o peptídeo sinal. As mesmas se agruparam corretamente quando analisadas com outras sequências de aminopeptidase em uma arvore fenogenética, Pode-se verificar a expressão em tempo real em diferentes tecidos (intestinal, adiposo e tegumento) da APN5 e APN6 e também de uma terceira aminopeptidase APN7 analisada nesta etapa do trabalho, onde APN7 apresentou expressão de 7,5 vezes mais no tegumento quando comparado com o intestino e de 4,9 vezes mais no tecido adiposo quando comparado com o intestino enquanto que a APN5 e APN6 apresentaram expressão relevante apenas no tecido do intestino. Estas identificações de APNs irão facilitar estudos para caracterizar interações de ligação com as toxinas Bt, proporcionando uma forma de compreender e evitar o desenvolvimento da resistência às proteínas Cry de B. thuringiensis. Estas informações são fundamentais para a elaboração de estratégias adequadas para o manejo da resistência de pragas e seu efetivo controle
Aminopeptidases N (APNs) are a class of ectoenzymes present in the midgut of lepidopteran larvae, which participates in setting the mode of action of Bacillus thuringiensis toxin (Bt). In this work, two aminopeptidases (OnAPN5 and OnAPN6) were cloned from cells of the intestine Ostrinia nubilalis, Lepidoptera pests of temperate maize. The two sequences were identified as APNs for the presence of motifs HEXXH18 (X) and E GAMEM as well as the signal peptide. The same when analyzed correctly grouped with other aminopeptidase sequences in a tree fenogenética, can check in real time the expression in different tissues (gut, adipose tissue and carcass) from APN5 and APN6 and also a third aminopeptidase analyzed in this step APN7 work, where APN7 showed expression of 7.5 times the carcass when compared with the intestine and 4.9 times in adipose tissue when compared with the intestine while APN5 and APN6 relevant only showed expression in tissue of the intestine. These IDs APNs will facilitate studies to characterize binding interactions with Bt toxins, providing a way to understand and prevent the development of resistance to Cry proteins of B. thuringiensis. This information is fundamental to the development of appropriate strategies for managing pest resistance and its effective control
8
Silva, Najara da. "Caracterização molecular e expressão de aminopeptidase (APNs) de Ostrinia nubilalis HÜBER 1796 (Lepidoptera: Crambidae) /". Jaboticabal, 2013. http://hdl.handle.net/11449/108433.
Testo completoAbstract (sommario):
Orientador: Manoel Victor Franco LemosBanca: Lucia Maria Carareto Alves
Banca: Vitor Fernandes Oliveira da Miranda
Banca: Cristina Lacerda Soares Petrarolha Silva
Banca: Renato Pariz Maluta
Resumo: Aminopeptidases N (APNs) são uma classe de ectoenzimas presentes no intestino médio das larvas de lepidópteros, que participa no cenário do modo de ação das toxinas Bacillus thuringiensis (Bt). No presente trabalho, duas aminopeptidases (OnAPN5 e OnAPN6) foram clonadas a partir células do intestino de Ostrinia nubilalis, lepidópteros praga do milho dos climas temperados. As duas sequências foram identificadas como APNs pela da presença dos motivos HEXXH18(X)E e GAMEM, bem como o peptídeo sinal. As mesmas se agruparam corretamente quando analisadas com outras sequências de aminopeptidase em uma arvore fenogenética, Pode-se verificar a expressão em tempo real em diferentes tecidos (intestinal, adiposo e tegumento) da APN5 e APN6 e também de uma terceira aminopeptidase APN7 analisada nesta etapa do trabalho, onde APN7 apresentou expressão de 7,5 vezes mais no tegumento quando comparado com o intestino e de 4,9 vezes mais no tecido adiposo quando comparado com o intestino enquanto que a APN5 e APN6 apresentaram expressão relevante apenas no tecido do intestino. Estas identificações de APNs irão facilitar estudos para caracterizar interações de ligação com as toxinas Bt, proporcionando uma forma de compreender e evitar o desenvolvimento da resistência às proteínas Cry de B. thuringiensis. Estas informações são fundamentais para a elaboração de estratégias adequadas para o manejo da resistência de pragas e seu efetivo controle
Abstract: Aminopeptidases N (APNs) are a class of ectoenzymes present in the midgut of lepidopteran larvae, which participates in setting the mode of action of Bacillus thuringiensis toxin (Bt). In this work, two aminopeptidases (OnAPN5 and OnAPN6) were cloned from cells of the intestine Ostrinia nubilalis, Lepidoptera pests of temperate maize. The two sequences were identified as APNs for the presence of motifs HEXXH18 (X) and E GAMEM as well as the signal peptide. The same when analyzed correctly grouped with other aminopeptidase sequences in a tree fenogenética, can check in real time the expression in different tissues (gut, adipose tissue and carcass) from APN5 and APN6 and also a third aminopeptidase analyzed in this step APN7 work, where APN7 showed expression of 7.5 times the carcass when compared with the intestine and 4.9 times in adipose tissue when compared with the intestine while APN5 and APN6 relevant only showed expression in tissue of the intestine. These IDs APNs will facilitate studies to characterize binding interactions with Bt toxins, providing a way to understand and prevent the development of resistance to Cry proteins of B. thuringiensis. This information is fundamental to the development of appropriate strategies for managing pest resistance and its effective control
Doutor
9
Coldebella, Ivanir José. "Índices zootécnicos, reprodutivos e parâmetros bioquímicos de fêmeas de jundiá Rhamdia quelen alimentadas com diferentes níveis de proteína e lipídio". Universidade Federal de Santa Maria, 2010. http://repositorio.ufsm.br/handle/1/4320.
Testo completoAbstract (sommario):
In this study were evaluated the zootechnics, reproductive aspects and biochemical s parameters aspects of female catfishes fed with three lipids and proteins levels on diets. Two experiments were conducted, the first being held between July 15th and October 15th, 2008, followed by a period of 14 days to create the post-larvae. We used 66
females with 14 months old (weight between 465,1 and 690,3g). 18 females were slaughtered for evaluation of biochemical s and histological parameters and 54 were
distributed on six 1m³-net cage, fed at 9 a.m. and 4 p.m., at ease, during 90 days, with pelletized rations containing 28, 34 and 40% of PB and 14% of total lipids. Twelve females were induced to spawn to reproductive evaluation (fertilization rate, egg s number, eggs and larvae s biometrics and prost-larvae s growth). At experiment I, the results indicated that the increase of protein s level at diet didn t influence the
zootechnics, reproductive and biochemical s parameters, however the 28% of PB level was superior for the post-larvae s growth on the variables weight, length and weight
versus survival in 14 days. The second experiment was performed between July 15th and October 15th, 2009, and we used the best diet of first experiment (28% of PB and
14% of lipids), settling the 8, 14 and 20% of lipids and 28% of PB levels. In this experiment was selected 93 females with 14 months old and weighting between 596,28
and 640,4g and 66 of which was distributed on six net cages and 27 was slaughtered for evaluation of biochemical s and histological parameters and the gonad's lipid profile. For both experiments were followed the same procedure, just adding, at the second, the evaluation of ovaries and muscles lipids profile. The results of experiment II also didn t show difference to the zootechnics and biochemical s parameters, but there was a linear increase in visceral fat index with the increased level of lipid in the diets. The fatty acids profile didn t differ between the treatments, but there was variation in concentration. The egg s diameter and area were significantly smaller to the 20% of lipids level, damaging the post-larvae s growth, survival and weight versus survival. The best reproductive s answers to catfishe s females were obtained with diets containing 28% of PB and between 8 and 14% of total lipids.Neste estudo avaliaram-se os aspectos zootécnicos, reprodutivos e parâmetros bioquímicos de fêmeas de jundiá alimentadas com três níveis protéicos e lipídicos nas dietas. Foram conduzidos dois experimentos, sendo o primeiro realizado entre 15 de julho e 15 de outubro de 2008, seguindo-se um período de mais 14 dias para a criação das pós-larvas. Utilizou-se 66 fêmeas com 14 meses de idade (peso entre 465,1 e 690,3 g). Foram abatidas 18 fêmeas para avaliação dos parâmetros bioquímicos e histológicos e 54 foram distribuídas em seis tanques-rede de 1m3, alimentadas às 9 e 16 h, a vontade, durante 90 dias, com rações peletizadas contendo 28, 34 e 40 % de PB e 14 % de lipídio total. Doze fêmeas foram induzidas à desova para avaliação da reprodução (taxa de fecundação, número de ovos, biometria dos ovos e larvas e crescimento das pós-larvas). No experimento I, os resultados indicaram que o aumento do nível de proteína nas dietas não influenciou os parâmetros zootécnicos, bioquímicos e reprodutivos, no entanto o nível de 28 % de PB mostrou-se superior para o crescimento das pós-larvas nas variáveis peso médio, comprimento total e peso versus sobrevivência aos 14 dias (P>0,05). O segundo experimento foi realizado no período entre 15 de julho e 15 de outubro de 2009 e utilizou-se a melhor dieta do experimento I (28 % PB e 14 % de lipídio), fixando-se os níveis em 8, 14 e 20 % de lipídio e 28 % de PB. Neste experimento foram selecionadas 93 fêmeas com 14 meses de idade e peso entre 596,28 e 640,4 g e 66 foram distribuídas em seis tanques-rede e 27 foram abatidas para avaliação dos parâmetros bioquímicos, histológicos e perfil lipídico das gônadas. Para os dois experimentos seguiram-se os mesmos procedimentos, apenas acrescido, no segundo, da avaliação do perfil lipídico dos ovários e músculos. Os resultados do experimento II igualmente não se mostraram diferentes para os parâmetros zootécnicos e bioquímicos, porém houve aumento linear do índice de gordura visceral com o aumento do nível de lipídio nas dietas. O perfil de ácidos graxos não diferiu entre os tratamentos. O diâmetro e a área do ovo foram significativamente menores para o nível de 20 % de lipídio, prejudicando o crescimento, sobrevivência e peso versus sobrevivência das pós-larvas (P>0,05). As melhores respostas reprodutivas para fêmeas de jundiá foram obtidas com as dietas contendo 28 % de PB e entre 8 e 14 % de lipídio total.
10
Bales, Michael Thomas. "Adaption to temperature in caddis larvae (Trichoptera)". Thesis, Keele University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.232893.
Testo completoAbstract (sommario):
The occunence of temperature acclimation was investigated in a range of caddis species. A closed bottle method was used for the majority of the respiration experiments, a flow-through respirometer being designed for the remaining experiments. Temperature acclimation was demonstrated in eight out of twelve species studied. Increased ability to compensate was associated with increased ecological distribution. The hydropsychids were shown to have a greater ability to acclimate than polycentropodids with similar distributions. No relationship was apparent between the interspecific differences in the respiration rate and the distribution of the species. For some species maintenance at a warmer temperature for 4-5 weeks caused a decrease in the undulatory activity of the larvae when compared, at a constant temperature, with larvae maintained at a cooler temperature. For eight of the ten species for which both sets of data were obtained the metabolic and undulatory data were compatible. A relationship between undulatory activity and distribution was suggested. For two cased caddis species a positive correlation was demonstrated between the number of gills and the body weight. Maintenance at the warmer of two temperatures over a period including a moult caused an increase in the number of gills on larvae and pupae. Intraspecific differences were found in the number of gills on larvae from different field sites, the number increasing with increased stream temperature. No relationship was demonstrated between the oxygen consumption of the larvae and the number of gills. No evidence was obtained for a difference in metabolism following maintenance of larvae at fluctuating temperatures of differing amplitudes.Decreased undulatory activity was demonstrated in larvae of Hydropsyche contuberna7is maintained under conditions of greater temperature fluctuations. Field acclimatisation was demonstrated in two species, Sericostoma personatum and Potamophy7ax cingu7atus, larvae from the warmer sites having a lower respiration rate than larvae of the same species from cooler sites, when both were measured at the same temperature.
11
Harrison, J. D. "Aspects of the ecology of amphibian larvae". Thesis, Cardiff University, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356737.
Testo completo
12
Jones, Huw. "Xenobiotic metabolism and zebrafish (danio rerio) larvae". Thesis, University of Birmingham, 2010. http://etheses.bham.ac.uk//id/eprint/886/.
Testo completoAbstract (sommario):
There is a requirement for the characterisation of the metabolism of xenobiotics in zebrafish larvae, due to the application of this organism to toxicity testing and ecotoxicology. Genes similar to mammalian cytochrome P450 (CYP) 1A1, CYP2B6, CYP3A5 and UDP-lucuronosyl-transferase (UGT) 1A1 were demonstrated to be expressed during normal embryonic development, with increased expression post hatching in Wik strain zebrafish larvae (72 hours post fertilisation, hpf). Activities towards ethoxy-resorufin, 7-ethoxy-coumarin and octyloxymethylresorufin, using an in vivo larval assay, were also detected in 96 hpf Wik strain zebrafish larvae, indicative of oxidative and conjugative metabolism. The expression of the identified genes was modulated upon exposure to Aroclor 1254, and the metabolic activities towards ethoxy-resorufin, 7-ethoxy-coumarin and octyloxymethylresorufin were observed to be inducible by exposure to in vitro inhibitors of CYP activities. Wik strain zebrafish larvae (72 hpf) were also demonstrated to metabolise the pharmaceuticals acetaminophen and ibuprofen by oxidative and conjugative processes using liquid chromatography mass spectrometry and scintillation counting. Finally, the organic solvents dimethyl-sulfoxide and methanol were observed to reduce the expression of CYP and UGT genes, and the metabolism of ethoxy-resorufin, after 24 hours exposure to \(\leq\)0.1% volume/volume concentrations of the two solvents. It is suggested that these inhibitory effects are in part due to a reduction in the expression of the aryl hydrocarbon receptors, which are known regulators of drug metabolism genes. Overall the expression of genes and enzymatic activities similar to the mammalian drug metabolism genes have been demonstrated in Wik strain zebrafish larvae (96 hpf), and the first examples of the metabolism of pharmaceuticals by zebrafish larvae are also demonstrated. The modulation of the metabolism of xenobiotics by organic solvents suggests that caution must be exercised when interpreting data from toxicity tests when high solvent concentrations are applied to zebrafish larvae. The continued use of zebrafish larvae as a toxicity testing model is strengthened by the findings of this work.
13
Juraimi, Salmah. "The Esterases of the Galleria Mellonella Larvae". TopSCHOLAR®, 1986. http://digitalcommons.wku.edu/theses/1736.
Testo completoAbstract (sommario):
Some properties of esterases of the greater wax moth larvae, Galleria mellonella (L.) were examined and the enzyme partially purified. Tris buffer was chosen as the buffer system over veronal buffer. The former causes less hydrolysis of the acetylsalicylic acid. Esterase activities were determined with acetylasalicylic acid in tris buffer (00.05 M, pH 7.85 with 0.1 M EDTA) and with acetyl-p-hydroxybenzoic acid in the same buffer. The enzyme was partially purified by combination of acetone powder preparation, ammonium sulfate precipitation, ion-exchange chromatography, and gel filtration.
The starting enzyme preparation was obtained from aceton powder preparation. The ratio of esterase activity to protein content was increased 1.36-fold by 70% ammonium sulfate precipitation. The ammonium sulfate in the 60-70% saturation range is reproducible with the highest specific activity at 60% saturation. The ammonium sulfate fractionation increased the stability of the enzyme preparation. After 24 hours more than 55% of enzyme activity from the ammonium sulfate precipitate still remained, whereas only about 40% of the enzyme activity from the acetone powder preparation remained.
The pH optimum was found to be 8.5 with acetyl-p-hydroxybenzoic acid as the substrate. The esterase had a linear increase in activity with increasing temperature. At 51°C, the specific activity was 27.60 micromoles/min mg protein in comparison to 12.94 micromoles/min mg protein at 20°C. The kinetic behavior of the enzyme with the different substrates was studied. The Vmax and Km values were 12.5 micromoles/min mg protein and 0.435 millimoles, respectively. The energy of activation with acetyl-p-hydroxybenzoic acid was 4.542 kcal K-1 mol-1.
The esterase activity was inhibited by mercuric chloride and veratrine sulfate. It was activated by the chelating agent, EDTA. The esterase activity was not affected by p-chloromercuribenzoic acid and eserine salicylate.
14
Le, Vay Lewis. "Nutritional studies on fish and crustacean larvae". Thesis, Bangor University, 1994. https://research.bangor.ac.uk/portal/en/theses/nutritional-studies-on-fish-and-crustacean-larvae(7c8004f1-ea27-4a8e-9d38-30c32f9ace4f).html.
Testo completoAbstract (sommario):
The effects of live foods and microencapsulated diets on growth, survival, body composition and digestive physiology of fish (mirror carp, Cyprinus =LQ) and penaeid shrimp ftna= japQnim) larvae were examined. Raising the lipid content of a microencapsulated enrichment diet from 18.3% to 33.6% improved accumulation of highly unsaturated fatty acids (HUFA) and total lipid in rotifers. Lipids in rotifers were assimilated by carp larvae, as demonstrated by improved growth and accumulation of HUFA in larvae reared on rotifers pre-fed the "high-lipid" diet. Poor diet digestibility coupled with low ingestion rates and low digestive enzyme activity in larvae were identified as contributing to the failure of a microencapsulated diet to support good growth and survival when fed directly to first-feeding carp. Preliminary testing indicates that digestibility of microencapsulated diets for fish larvae can be improved by inclusion of pancreatin. Experiments with Penaeus japonicus indicate that dietary requirements for protein, energy and HUFA by penaeid larvae are lower than previously thought. Foods of low protein content (Chaetoceros gladlia) or low digestibility (microencapsulated diet) elicited high trypsin activity in mysis larvae, compared to those fed Artemia. Larvae receiving both C , gmcilis and Artemi exhibited an intermediate level of trypsin activity - which may explain the superior growth and protein retention in postlarvae reared on the mixed regime. A microencapsulated diet did not support growth and carbon and nitrogen retention equivalent to that in larvae fed live food, despite the strong trypsin response, in mysis larvae. When used together with a low density of _C, p-racilis the microencapsulated diet produced postlarvae of the same size and tissue composition as those reared using live food. It is suggested that the algal co-feed may enhance growth through stimulation of trypsin secretion, supply of extra digestible nutrients or provision of unidentified specific growth enhancing factor(s).
15
Timmins, William Andrew. "Control of feeding in Manduca sexta larvae". Thesis, University of Bath, 1988. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380387.
Testo completo
16
Krug, Patrick Joseph. "Chemical and larval ecology of opisthobranch molluscs : variable development modes and settlement cues for larvae of Alderia modesta /". Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 1998. http://wwwlib.umi.com/cr/ucsd/fullcit?p9907826.
Testo completo
17
Taha, Awad Khalafalla. "Ecology of Aedes cantans (Meigen) larvae and effects of Bacillus thuringiensis var. israelensis on mosquito larvae and non-target organisms". Thesis, University of Newcastle Upon Tyne, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.357080.
Testo completo
18
Rice, Kevin Barry. "Cascading Ecological Impacts of Emerald Ash Borer: Tritrophic Interactions Between Prickly Ash, Giant Swallowtail Butterfly Larvae, and Larval Predators". The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1366373364.
Testo completo
19
Braun, Andreas 1983. "Multisensory integration and decision-making in Drosophila larvae". Doctoral thesis, Universitat Pompeu Fabra, 2016. http://hdl.handle.net/10803/565760.
Testo completoAbstract (sommario):
Numerous studies have shown that a wide range of behaviors from sensory processing to motor control involve near-optimal probabilistic inference. Most of these studies have focused on vertebrates, suggesting that the ability to perform probabilistic inference requires large nervous systems. Yet, neural theories of probabilistic inference can be implemented with the most basic neural networks. To explore the possibility that organisms with small nervous systems perform near-optimal probabilistic inference, I tested the ability of Drosophila larvae to integrate information from unisensory and multisensory cues.
Larvae were placed in a circular behavioral arena, where their positions were monitored during exposure to single or combined sensory gradients. Combined gradients consisted either of two odor gradients or a thermosensory and an odor gradient, to test within and cross-modal integration respectively. In collaboration with theorists, I predicted the optimal behavior for the combined gradients given the behavior in the single sensory conditions, with a Bayesian model. The behavior of the larvae matched the predictions of the Bayesian model closely for both, the within and cross-modal, scenarios of integration. Another suboptimal model with fixed weights failed to predict the combined behavior. This work sets the stage for a systematic analysis of the neural computations underlying probabilistic inference in an insect brain amenable to genetic manipulations and physiological inspections.Numerosos estudios han demostrado que una amplia gama de comportamientos, desde el procesamiento sensorial al control motor, intervienen en la inferencia probabilística casi-óptima. La mayoría de estos estudios se centran en vertebrados, surigiéndo que se requiere de un sistema nervioso complejo para desarrollar dicha inferencia probabilística. Sin embargo, las teorías neutrales de inferencia probabilística pueden ser implementadas con redes neuronales mas básicas. Para investigar si organismos que poseen un reducido sistema nervioso son capaces de desarrollar inferencia probabilística casi-óptima, he examinado la habilidad que posee la larva de Drosophila para integrar información proveniente de señales uni y multisensoriales. Las larvas se colocaron en una area circular, donde se examinaron sus posiciones en función del gradiente único o combinado al que fueron expuestas. Los gradientes combinados consisten en dos gradientes de olor o bien en uno de olor y el otro termo sensorial, para así examinar la integración intramodal o intermodal respectivamente. En colaboración con teóricos y aplicando el modelo Bayesian, predije el comportamiento óptimo para gradientes combinados partiendo del comportamiento observado en condiciones de gradiente único. El comportamiento de la larva se ajustó a las predicciones del modelo Bayesian para ambos escenarios de integración, el intra e intermodal. Sin embargo, el modelo sub-óptimo con pesos fijos falló en la predicción del comportamiento combinado. Este trabajo sienta las bases para un análisis sistemático de los cómputos neuronales corroborando la inferencia probabilística en cerebros de insectos susceptibles a manipulaciones genéticas e inspecciones fisiológicas.
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Mason, Benjamin M. "Evidence for Opsin-Based Photosensitivity in Coral Larvae". Scholarly Repository, 2011. http://scholarlyrepository.miami.edu/oa_dissertations/524.
Testo completoAbstract (sommario):
Photosensitive behaviors and circadian rhythms are well documented in reef-building corals and their larvae, yet photoreceptive structures and opsins have not been described in these organisms. Here I provide evidence for red sensitivity in several species of coral larvae. Behavioral experiments with two Caribbean corals, Porites astreoides and Acropora palmata demonstrated that larvae settle and metamorphose at a greater frequency on red substrata than on similar substrata of other colors. Attachment to red substrata was not observed when larvae were maintained in the dark, suggesting that red sensitivity was responsible for the observed behavior. Extracellular recordings confirm photosensitivity and indicate that the peak sensitivity of coral photoreceptors are shifted towards the orange-red region of the visible light spectrum, similar to the spectra (fluorescence and reflectance) of preferred artificial (plastic) and natural (crustose coralline algae) settlement substrata. Using Blast analyses and a PCRbased approach, I have identified, sequenced and cloned two full-length opsin cDNAs from A. palmata larvae. One cDNA (Acropsin 1) encodes an opsin protein that is similar to a vertebrate melanopsin; the second (Acropsin 2) encodes a protein that is most similar to cephalopod rod opsin. I have successfully developed synthetic peptide antibodies against each Acropsin 1 and Acropsin 2. Western blots of adult A. palmata and A. cervicornis protein detect a 37kDa and 40kDa band, corresponding to the predicted molecular weights of Acropsins 1 and 2, respectively. Immunohistochemistry confirms expression of both opsins in A. palmata larvae. Staining of sectioned larvae demonstrates that Acropsin 1 is localized in the larval gastroderm while Acropsin 2 is localized in solitary epithelial cells, scattered throughout the larval ectoderm but with a polarized distribution and higher concentration in the aboral epidermis. This research provides several lines of evidence to support the existence, and demonstrate one potential ecological function, of opsin-based photosensitivity in corals.
21
Wang, Zhi. "Functional study of hemolymph coagulation in Drosophila larvae". Doctoral thesis, Stockholms universitet, Institutionen för molekylärbiologi och funktionsgenomik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-75179.
Testo completoAbstract (sommario):
Many pathogen infections in nature are accompanied by injury and subsequent coagulation. Despite the contribution of hemolymph coagulation to wound sealing, little is known about its immune function. Based on the molecular knowledge of Drosophila innate immunity, this thesis investigated the immune function of clot both in vitro and in vivo, the immune relevant genes involved in a natural infection model, involving entomopathgenic nematodes (EPN) and the factors leading to crystal cell activation. Transglutaminase (TG) and its substrate Fondue (Fon) have been identified as bona fide clot components in Drosophila larvae. By knocking down TG or Fon via RNAi, we observed an increased susceptibility to EPN in larvae. In addition, this increased susceptibility was associated with an impaired ability of hemolymph clots to entrap bacteria. Immunostaining revealed that both clot components (Fon and TG) were able to target microbial surfaces. All these data suggest an immune function for the Drosophila hemolymph clot. Strikingly, similar results were obtained when we ran parallel experiments with human FXIIIa, an ortholog of Drosophila TG, indicating a functional conservation. We also found evidence for the regulation on both clot and immunity by eicosanoids in Drosophila larvae. The combination of EPN infection with the Drosophila model system allowed us to discover an immune function for TEP3 and Glutactin. However the molecular mechanism underlying the involvement of these two proteins in this particular host-pathogen interaction remains to be elucidated. Prophenoloxidase, the proform of enzyme involved in hardening the clot matrix, has been shown to be released by rupture of crystal cells. This cell rupture is dependent on activation of the JNK pathway, Rho GTPases and Eiger. Our work further identified the cytoskeletal component, Moesin, and the cytoskeletal regulator Rac2 as mediators of cell rupture. Despite the possible role of caspases in crystal cell activation, such cell rupture was turned out to be different from apoptosis. The implication of Rab5 in this process indicated that proper endocytosis is required for cell activation and subsequent melanization. Our findings furthered not only our understanding of the release of proPO via cell rupture but also our knowledge on different paths of immune cell activation.At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: In press. Paper 4: Manuscript.
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Kamarudin, Mohd Salleh. "Studies on the digestive physiology of crustacean larvae". Thesis, Bangor University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.386958.
Testo completo
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Pan, Anon Maria. "Decapod crustacean larvae in Scottish (UK) coastal plankton". Thesis, University of Aberdeen, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.499700.
Testo completoAbstract (sommario):
Decapod larval assemblages were studied at two sites in Scottish coastal waters, Stonehaven and Loch Ewe. Plankton data from 4.5 years at Stonehaven and from 2 years at Loch Ewe were analysed, allowing the study of decapod larval cycles, species composition and seasonality at these locations. An 8 years time series of weekly data on total abundance of decapod larvae from Stonehaven and 4 years and 8 months time series from Loch Ewe were also studied. The influence of environmental variables in the patterns observed was analysed using mixed modelling techniques. The results showed differences in abundance, although not in diversity, between the two sampling locations. The temperature was the main factor affecting the patterns observed, followed by food availability (expressed as chlorophyll a) and salinity. Artificial substrates were employed to study the settlement and the early establishment phases for the decapod community at Stonehaven area. Species composition and occurrence of megalopae and juveniles and links with the mesoplanktonic larvae were studied. A significant correlation was detected between the abundance of megalopae and early juveniles in the collectors and the abundance of decapod larvae in the plankton a month earlier. The same was observed for the species Pisidia longicornis, but not for other taxa. Real-Time PCR was successfully employed in the identification of Liocarcinus depurator, Cancer pagurus, Carcinus maenas and Necora puber larvae. This technique allowed inference of the annual cycle of L. depurator and showed the potential of this method to obtain relative quantifications of the larvae. A photographic guide for the decapod species identified was created, providing a good overview of the species present in these two Scottish coastal locations, useful as a complementary tool to the dichotomous keys.
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Chan, Ying-shan, e 陳映姗. "Effects of silver nanoparticles on marine invertebrate larvae". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/208175.
Testo completoAbstract (sommario):
Silver nanoparticles (AgNPs) have gained much popularity in consumer products due to their strong antimicrobial ability. The majority of research concerning the biological effects of AgNPs has been limited to humans, mammals and freshwater organisms. Marine organisms, especially invertebrates, have been studied to a lesser extent. The objective of this thesis was to understand the effects of AgNPs on the marine benthic invertebrates. Specifically, we focused on the acute and sub-lethal toxicity of two AgNPs (Oleic acid coated AgNP (OAgNP) and Polyvinylpyrrolidone coated AgNP (PAgNP)) on marine invertebrate larvae across three phyla (i.e. the barnacle Balanus amphitrite, the limpet Crepidula onyx and the polychaete Hydroides elegans) in terms of mortality, growth, development and metamorphosis. Bioaccumulation and biodistribution of silver, as well as apoptosis induction were also investigated. To distinguish the toxic effects derived from nano-silver and aqueous form of silver, larvae were also exposed to silver nitrate (SN) in parallel.
In the acute toxicity test, larvae were exposed to OAgNPs and PAgNPs for 48 hours, and the concentration leading to 10 % mortality (〖LC〗_10) were determined and compared. The results indicated that B. amphitrite and H. elegans were more sensitive to OAgNPs (〖LC〗_10: 0.138 and 2.63 × 〖10〗^(-4) μμg L-1, respectively) than PAgNPs (〖LC〗_10: 0.502 and 0.317 μμg L^(-1), respectively). In contrast, C. onyx was more susceptible to PAgNPs (LC10: 38.5 μμg L^(-1)) than OAgNPs (〖LC〗_10: 467 μμg L^(-1)). Among the three taxonomic groups, C. onyx was most tolerant of AgNPs, following by B. amphitrite and H. elegans.
The sub-lethal effect of AgNPs resulted in a significant retardation in growth and development, and the reduction of settlement rate of all three species tested. In particular, the settlement rate of H. elegans was significantly lower in AgNPs treatment than in SN treatment, suggesting that toxicity of AgNPs might not be solely evoked by the release of silver ion (Ag+) into the test solution. The three species took up and accumulated silver efficiently from all forms. Importantly, AgNP aggregates were found along the digestive tract of C. onyx and the TEM images further confirmed that AgNPs were able to move across the plasma membrane. In addition, TUNEL assay indicated that AgNPs could induce apoptosis in B. amphitrite and C. onyx. In view of the very low number of detected apoptotic cells and the random occurrence of cell death found, AgNP-induced apoptosis does not appear to be the major toxicity mechanism in causing delayed growth and settlement failure. Unlike the results revealed from acute toxicity test, surface coatings did not affect the sub-lethal toxicity of AgNPs.
This research clearly demonstrated that AgNPs exerted toxic effects in a speciesspecific manner, and long-term exposure of AgNPs might allow bioaccumulation of silver, induce apoptosis, and affect growth, development and recruitment of marine invertebrates. This study also highlighted the possibility that toxicity of AgNPs might be mediated through toxic Ag+ as well as the novel modalities of AgNPs.published_or_final_version
Biological Sciences
Master
Master of Philosophy
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Panagiotaki, Panagiota. "The development of size variation in flatfish larvae". Thesis, University of Liverpool, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317241.
Testo completo
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Baldwin, Carole Christine. "Larvae and relationships of epinepheline serranids (Teleostei: Percoidei)". W&M ScholarWorks, 1992. https://scholarworks.wm.edu/etd/1539616557.
Testo completoAbstract (sommario):
Morphology is described for larvae of Diploprion bifasciatus, Belonoperca chabanaudi, Jeboehlkia gladifer, and Grammistes sexlineatus of the serranid subfamily Epinephelinae. Known larvae of all epinephelines are compared. Larval epinephelines differ in patterns of pigmentation, head spination, sequence of fin formation and morphology of elongate (often spectacularly so!) dorsal-fin spines. Relationships among epinepheline genera are investigated based on phylogenetic analysis of larval and adult morphology. Five monophyletic tribes are cladistically delineated, and relationships among tribes and among genera of the tribe Grammistini are hypothesized. Generic composition of tribes differs from Johnson's (1983) classification only in the allocation of Jeboehlkia to the tribe Grammistini rather than the Liopropomini. Despite the presence of the ichthyotoxin grammistin in the Diploprionini and Grammistini, the latter is proposed to be the sister group of the Liopropomini. This hypothesis is based, in part, on previously unrecognized larval features. Larval morphology also provides convincing evidence of monophyly of the subfamily Epinephelinae, the clade comprising all epinepheline tribes except Niphonini, and the tribe Grammistini. Larval features provide the only evidence of a monophyletic Epinephelini and a monophyletic clade comprising the Diploprionini, Liopropomini and Grammistini; identification of larvae of more epinephelines is needed to test those hypotheses. Within the tribe Grammistini, Jeboehlkia gladifer is hypothesized to be the sister group of a natural assemblage comprising the former pseudogrammid genera (Aporops, Pseudogramma and Suttonia). The "soapfishes" (Grammistes, Grammistops, Pogonoperca and Rypticus) are not monophyletic, but form a series of sequential sister groups of Jeboehlkia, Aporops, Pseudogramma and Suttonia (the closest of these being Grammistops, followed by Rypticus, then Grammistes plus Pogonoperca). The absence in adult Jeboehlkia of several derived features shared by Grammistops, Aporops, Pseudogramma and Suttonia is incongruous with this hypothesis but may be attributable to paedomorphosis. The generic phylogeny of the Grammistini proposed herein emerges as the single most parsimonious hypothesis largely because of the method chosen for analyzing multistate characters. This study demonstrates that ontogeny is valuable in phylogenetic studies as a source of characters, means of assessing homology and aid to identifying heterochrony.
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Hong, S. Y. "Phylogenetic studies on the larvae of decapod crustaceans". Thesis, University of Liverpool, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.233923.
Testo completo
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Miner, Benjamin G. "Evolution of phenotypic plasticity insights from echinoid larvae /". Connect to this title online, 2003. http://purl.fcla.edu/fcla/etd/UFE0001450.
Testo completo
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Rethwisch, Michael D., e S. Sherwood Winans. "Control of Liriomyza trifolii Larvae in Head Lettuce". College of Agriculture, University of Arizona (Tucson, AZ), 1989. http://hdl.handle.net/10150/214282.
Testo completo
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Clark, Matthew. "Neural Basis of Locomotion in Drosophila Melanogaster Larvae". Thesis, University of Oregon, 2018. http://hdl.handle.net/1794/23170.
Testo completoAbstract (sommario):
Drosophila larval crawling is an attractive system to study patterned motor output at the level of animal behavior. Larval crawling consists of waves of muscle contractions generating forward or reverse locomotion. In addition, larvae undergo additional behaviors including head casts, turning, and feeding. It is likely that some neurons are used in all these behaviors (e.g. motor neurons), but the identity (or even existence) of neurons dedicated to specific aspects of behavior is unclear. To identify neurons that regulate specific aspects of larval locomotion, we performed a genetic screen to identify neurons that, when activated, could elicit distinct motor programs. We defined 10 phenotypic categories that could uniquely be evoked upon stimulation, and provide further in depth analysis of two of these categories to understand the origins of the evoked behaviors.
We first identified the evolutionarily conserved Even-skipped+ interneuron phenotype (Eve/Evx). Activation or ablation of Eve+ interneurons disrupted bilaterally symmetric muscle contraction amplitude, without affecting left-right synchronous timing. TEM reconstruction places the Eve+ interneurons at the heart of a sensorimotor circuit capable of detecting and modifying body wall muscle contraction
We then went on to identify a unique pair of descending neurons dubbed the ‘Mooncrawler’ descending neurons (McDNs) to be sufficient to generate reverse locomotion. We show that the McDNs are present at larval hatching, function during larval life, and are remodeled during metamorphosis while maintaining basic morphological features and neural functions necessary to generate backwards locomotion. Finally, using serial section Transmission Electron Microscopy (ssTEM) to map neural connections to upstream and downstream elements provides a mechanistic view of how sensory information is received by the McDNs and transmitted to the VNC motor system to perform backwards locomotion. Finally, we show that these McDNs are the same as those identified in recent work in Drosophila adults (Bidaye et al. 2014) to be sufficient to generate reverse locomotion.
This dissertation includes previously published, co-authored material.
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Chandler, Darren Robert. "Effects of acylurea insecticide in Manduca sexta larvae". Thesis, University of Bath, 1991. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303547.
Testo completo
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Richardson, Katherine. "Studies on the population dynamics of Teladorsagia circumcincta". Thesis, University of Glasgow, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366339.
Testo completo
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Gonçalves, Janina Carvalho. "Avaliação de esporos de Paenibacillus larvae subsp. larvae em mel de apiários do Estado do Piauí e de métodos de detecção". Universidade Federal de Viçosa, 2004. http://www.locus.ufv.br/handle/123456789/9944.
Testo completoAbstract (sommario):
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Este trabalho teve como objetivo investigar a presença de Paenibacillus larvae subsp. larvae em mel de colméias do Estado do Piauí, pelo método analítico oficial brasileiro, e avaliar modificações nesta metodologia para reduzir seu limite de detecção. Esporos de P. larvae subsp. larvae não foram detectados em mel das colméias de diferentes regiões do Estado do Piauí. Comparando meios de cultura, o ágar P. larvae isolou maior número esporos desta bactéria presentes em mel e inibiu do mesmo modo contaminantes aeróbios presentes. A diluição de uma parte de mel em quatro partes de solução salina fosfatada tamponada recuperou maior número de esporos P. larvae subsp. larvae presentes em mel. As forças centrífugas 6000 g e 8000 por 30 ou 40 minutos não diferiram entre si, contudo recuperaram maior número de esporos de P. larvae subsp. larvae em comparação com a oficialmente recomendada. A redução no limite de detecção é relevante para analise de mel, principalmente, quando o patógeno encontra-se em quantidades mínimas, tanto na colméia quanto no produto comercializado.
This work had the following aims: detect the presence of Paenibacillus larvae subsp. larvae spores in honey collected in Piauí State apiaries using official Brazilian analytical method and to verify modifications in this methodology to reduce its detection limit. Spores of P. larvae subsp. larvae were not found in honey of hives from different regions of Piauí State. Comparing mediums, P. larvae agar isolated bigger spores quantities of these bacteria found in honey and inhibited, in the same way, other aerobical bacteria presented. Addition of one part of honey in four parts of phosphate buffer saline pH 7.2 isolated a bigger number of P. larvae subsp. larvae spores presented in honey. Comparisons between centrifuge forces of 6000 g and 8000 during 30 or 40 minutes showed that they were not different, however they recuperated a bigger number of P. larvae subsp. larvae spores than centrifuge force recommended in Brazilian law. Reduction in detection limit is important to honey analyses, mainly when pathogen is present in minimal quantities in hives or in commercialized product.
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Aguirre-Gil, Oniel Jeremías [UNESP]. "Parâmetros de produção de Chrysomya megacephala (Fabr., 1794) (Diptera: Calliphoridae) em dietas e densidades larvais, com vistas à alimentação animal". Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/91312.
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aguirregil_oj_me_jabo.pdf: 820756 bytes, checksum: 73aa85c9cdc05d6bc69ba37795d60c4b (MD5)O objetivo do trabalho foi gerar informações sobre alguns parâmetros biológicos de Chrysomya megacephala sob diferentes situações, como tipos de dietas, densidades larvais e quantidades de dietas. Foi adotado um delineamento fatorial de 4x3x3 (4 tipos de dietas, 3 densidades larvais e 3 quantidades de dietas). Estas informações são importantes para o planejamento da produção comercial de larvas, como alternativa na alimentação de peixes, rãs e pássaros. O incremento da porcentagem de farelo de arroz nos tipos de dietas prolongou a duração do período larval, além da diminuição na viabilidade larval e no peso total médio de larvas. No parâmetro densidade larval, a duração do período larval foi relativamente estável, a maior viabilidade larval foi atingida pela densidade de 5 larvas/g de dieta e o maior peso total médio de larvas foi obtido na densidade de 10 larvas/g de dieta. O incremento das quantidades de dietas provoca estabilização da duração do período larval e da viabilidade larval, além da diminuição constante do peso total médio de larvas. Na análise de interação de fatores, os parâmetros biológicos estudados apresentam a mesma tendência encontrada nos tipos de dietas indicando diminuição da duração do período larval e peso total médio de larval com aumento da viabilidade larval conforme incrementam as densidades larvais e quantidades de dietas. No geral, os parâmetros biológicos estudados são afetados pelo incremento da porcentagem de farelo de arroz na dietas mesmo nas diferentes densidades larvais e quantidades de dietas.
The objective was to get information about larval period, larval viability and total weight of larvae rearing on different situations, such as diet, larval densities and quantities of diet. Foi adotado um delineamento fatorial de 4x3x3 (4 tipos de dietas, 3 densidades larvais e 3 quantidades de dietas). It was used a factorial design 4x3x3 (4 diets, 3 larval densities and 3 quantities of diets). These information are important in the planning of larval production, as alternative food of animals, like fish, frogs and birds. The increase of percentage of rice ban increased the duration of larval period, and decreased the larval viability and the average total weight of larvae. In the larval densities, the duration of larval period was stable; the major viability was reached in the larval density of 5 larvae/g of diet and the major average total weight of larvae was in 10 larvae/g of diet. The increase in the quantity of diet, promoted stabilization in the duration of larval period and larval viability, and the constant decrease of the average total weight of larvae. In the analyses of factorial interaction, the biological parameters in study showed the same trend found in the diets suggesting decrease of the duration of larval period and average total weight with increase of larval viability when increase the larval densities and quantities of diets. In general, the biological parameters are affected for the increase in the percentage of rice ban in the diets, even in different larval densities and quantities of diets.
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Ferreira, Luana Malheiros [UNESP]. "Desenvolvimento inicial e densidade de estocagem de larvas de Aracu-riscado, Leporinus agassizii (Characiformes: Anostomidae)". Universidade Estadual Paulista (UNESP), 2015. http://hdl.handle.net/11449/132588.
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000854796.pdf: 3287498 bytes, checksum: 5389246fc289aed76f7b12139edf692c (MD5)Estudos para produção de formas jovens de peixes são fundamentais para o desenvolvimento da piscicultura e o manejo das populações naturais. Leporinus agassizii é apreciado nas distintas modalidades de pesca (comercial, artesanal, ornamental e esportiva), além de apresentar características desejáveis para a criação. Objetivou-se descrever o desenvolvimento embrionário e a densidade de estocagem de larvas do aracu-riscado, L. agassizii. Reprodutores foram submetidos a reprodução induzida por hipofisação, com a temperatura da água a 28,6 ± 0,7ºC, no Centro de Capacitação e Produção de Alevinos, pertencente ao Instituto Federal de Educação Ciência e Tecnologia, São Gabriel da Cachoeira, Amazonas, Brasil, no mês de setembro de 2014. Logo após a fertilização, os ovos foram mantidos em incubadoras (60L), com a temperatura média da água de 28,4 ± 0,7 ºC. Coletaram-se amostras de ovos em intervalos de 10 min, durante as primeiras três horas pós-fertilização (PF) e, posteriormente, em intervalos de 30min até a eclosão das larvas, para observação em estereomicroscópio equipado com câmera CMOS digital colorida, 10.0 MP e software para captura e análise de imagens (ISCapture). O efeito da densidade de estocagem de larvas do L. agassizii foi avaliado ao longo do 4º e 14º dias após a eclosão (DAE). Foram utilizadas 3600 larvas no 4º DAE, encontrando-se estas com o saco vitelínico totalmente absorvido, boca aberta e mantidas em jejum. As larvas foram submetidas às densidades de 5 (D5), 15 (D15) e 25 (D25) larvas.L-1, em caixas de polietileno (0,63 x 0,45 x 0,32 m), com 20 L de água. Utilizou-se um delineamento inteiramente casualizado com quatro repetições. As larvas foram alimentadas seis vezes ao dia, sendo cada refeição composta por náuplios de Artemia, na proporção 50 náuplios.larva-1 (4º ao 6º DAE), 100 (7º ao 9º DAE), 200 (10° ao 11º DAE) e 400 (12º ao 13º DAE) e por ração...
Studies for the production of young fish shapes are key to the development of fish farming and the management of natural populations. Leporinus agassizii is appreciated in the different fishing methods (commercial, craft, ornamental and sports), and present desirable features for creation. This study aimed to describe the embryonic and larval stocking density of aracu-riscado, L. agassizii. Players underwent reproduction induced hypophysation, with the water temperature at 28.6±0.7 °C, the Centro de Capacitação e Produção de Alevinos belonging to the Instituto Federal de Educação, Ciência e Tecnologia, São Gabriel da Cachoeira, Amazonas, Brazil, in September 2014. After fertilization, the eggs were kept in incubators (60 Litre), with the average water temperature of 28.4±0.7 °C. Samples were collected 10 min intervals on eggs during the first three hours after fertilization (AF) and thereafter at intervals of 30 minutes until the outbreak of the larvae, for observation in stereo equipped with digital color CMOS camera, 10.0 MP and software to capture and analyze images (ISCapture). The effect of larval stocking density of L. agassizii was assessed over 4th and 14th days after hatching (DAH). 3600 larvae were used in the 4th DAH, meeting these with the yolk sac fully absorbed, mouth open and fasted. The effect of larval stocking density of L. agassizii was assessed over 4th and 14th (DAH). 3600 larvae were used in the 4th DAH, meeting these with the yolk sac fully absorbed, mouth open and fasted. The larvae were subjected to density of 5 (D5), 15 (D15) and 25 (D25) larvas.L-1, in polyethylene boxes (0.63 x 0.45 x 0.32 m) with 20 Litre of water. We used a completely randomized design with four replications. The larvae were fed six times a day, each meal consisting of Artemia in the proportion 50 náuplios.larva-1 (4th to 6th DAH), 100 (7th to 9th DAH), 200 (10th to 11th DAH) and 400 (12th to 13th DAH) and commercial diet ...
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Aguirre-Gil, Oniel Jeremías. "Parâmetros de produção de Chrysomya megacephala (Fabr., 1794) (Diptera: Calliphoridae) em dietas e densidades larvais, com vistas à alimentação animal /". Jaboticabal, 2013. http://hdl.handle.net/11449/91312.
Testo completoAbstract (sommario):
Orientador: Antonio Carlos BusoliBanca: Arlindo Leal Boiça Junior
Banca: Marcos Doniseti Michelotto
Resumo: O objetivo do trabalho foi gerar informações sobre alguns parâmetros biológicos de Chrysomya megacephala sob diferentes situações, como tipos de dietas, densidades larvais e quantidades de dietas. Foi adotado um delineamento fatorial de 4x3x3 (4 tipos de dietas, 3 densidades larvais e 3 quantidades de dietas). Estas informações são importantes para o planejamento da produção comercial de larvas, como alternativa na alimentação de peixes, rãs e pássaros. O incremento da porcentagem de farelo de arroz nos tipos de dietas prolongou a duração do período larval, além da diminuição na viabilidade larval e no peso total médio de larvas. No parâmetro densidade larval, a duração do período larval foi relativamente estável, a maior viabilidade larval foi atingida pela densidade de 5 larvas/g de dieta e o maior peso total médio de larvas foi obtido na densidade de 10 larvas/g de dieta. O incremento das quantidades de dietas provoca estabilização da duração do período larval e da viabilidade larval, além da diminuição constante do peso total médio de larvas. Na análise de interação de fatores, os parâmetros biológicos estudados apresentam a mesma tendência encontrada nos tipos de dietas indicando diminuição da duração do período larval e peso total médio de larval com aumento da viabilidade larval conforme incrementam as densidades larvais e quantidades de dietas. No geral, os parâmetros biológicos estudados são afetados pelo incremento da porcentagem de farelo de arroz na dietas mesmo nas diferentes densidades larvais e quantidades de dietas.
Abstract: The objective was to get information about larval period, larval viability and total weight of larvae rearing on different situations, such as diet, larval densities and quantities of diet. Foi adotado um delineamento fatorial de 4x3x3 (4 tipos de dietas, 3 densidades larvais e 3 quantidades de dietas). It was used a factorial design 4x3x3 (4 diets, 3 larval densities and 3 quantities of diets). These information are important in the planning of larval production, as alternative food of animals, like fish, frogs and birds. The increase of percentage of rice ban increased the duration of larval period, and decreased the larval viability and the average total weight of larvae. In the larval densities, the duration of larval period was stable; the major viability was reached in the larval density of 5 larvae/g of diet and the major average total weight of larvae was in 10 larvae/g of diet. The increase in the quantity of diet, promoted stabilization in the duration of larval period and larval viability, and the constant decrease of the average total weight of larvae. In the analyses of factorial interaction, the biological parameters in study showed the same trend found in the diets suggesting decrease of the duration of larval period and average total weight with increase of larval viability when increase the larval densities and quantities of diets. In general, the biological parameters are affected for the increase in the percentage of rice ban in the diets, even in different larval densities and quantities of diets.
Mestre
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Ferreira, Luana Malheiros. "Desenvolvimento inicial e densidade de estocagem de larvas de Aracu-riscado, Leporinus agassizii (Characiformes: Anostomidae) /". Jaboticabal, 2015. http://hdl.handle.net/11449/132588.
Testo completoAbstract (sommario):
Orientador: Elizabeth RomagosaBanca: Sérgio de Medeiros Ferraz
Banca: Sérgio Ricardo Batlouni
Resumo: Estudos para produção de formas jovens de peixes são fundamentais para o desenvolvimento da piscicultura e o manejo das populações naturais. Leporinus agassizii é apreciado nas distintas modalidades de pesca (comercial, artesanal, ornamental e esportiva), além de apresentar características desejáveis para a criação. Objetivou-se descrever o desenvolvimento embrionário e a densidade de estocagem de larvas do aracu-riscado, L. agassizii. Reprodutores foram submetidos a reprodução induzida por hipofisação, com a temperatura da água a 28,6 ± 0,7ºC, no Centro de Capacitação e Produção de Alevinos, pertencente ao Instituto Federal de Educação Ciência e Tecnologia, São Gabriel da Cachoeira, Amazonas, Brasil, no mês de setembro de 2014. Logo após a fertilização, os ovos foram mantidos em incubadoras (60L), com a temperatura média da água de 28,4 ± 0,7 ºC. Coletaram-se amostras de ovos em intervalos de 10 min, durante as primeiras três horas pós-fertilização (PF) e, posteriormente, em intervalos de 30min até a eclosão das larvas, para observação em estereomicroscópio equipado com câmera CMOS digital colorida, 10.0 MP e software para captura e análise de imagens (ISCapture). O efeito da densidade de estocagem de larvas do L. agassizii foi avaliado ao longo do 4º e 14º dias após a eclosão (DAE). Foram utilizadas 3600 larvas no 4º DAE, encontrando-se estas com o saco vitelínico totalmente absorvido, boca aberta e mantidas em jejum. As larvas foram submetidas às densidades de 5 (D5), 15 (D15) e 25 (D25) larvas.L-1, em caixas de polietileno (0,63 x 0,45 x 0,32 m), com 20 L de água. Utilizou-se um delineamento inteiramente casualizado com quatro repetições. As larvas foram alimentadas seis vezes ao dia, sendo cada refeição composta por náuplios de Artemia, na proporção 50 náuplios.larva-1 (4º ao 6º DAE), 100 (7º ao 9º DAE), 200 (10° ao 11º DAE) e 400 (12º ao 13º DAE) e por ração...
Abstract: Studies for the production of young fish shapes are key to the development of fish farming and the management of natural populations. Leporinus agassizii is appreciated in the different fishing methods (commercial, craft, ornamental and sports), and present desirable features for creation. This study aimed to describe the embryonic and larval stocking density of aracu-riscado, L. agassizii. Players underwent reproduction induced hypophysation, with the water temperature at 28.6±0.7 °C, the Centro de Capacitação e Produção de Alevinos belonging to the Instituto Federal de Educação, Ciência e Tecnologia, São Gabriel da Cachoeira, Amazonas, Brazil, in September 2014. After fertilization, the eggs were kept in incubators (60 Litre), with the average water temperature of 28.4±0.7 °C. Samples were collected 10 min intervals on eggs during the first three hours after fertilization (AF) and thereafter at intervals of 30 minutes until the outbreak of the larvae, for observation in stereo equipped with digital color CMOS camera, 10.0 MP and software to capture and analyze images (ISCapture). The effect of larval stocking density of L. agassizii was assessed over 4th and 14th days after hatching (DAH). 3600 larvae were used in the 4th DAH, meeting these with the yolk sac fully absorbed, mouth open and fasted. The effect of larval stocking density of L. agassizii was assessed over 4th and 14th (DAH). 3600 larvae were used in the 4th DAH, meeting these with the yolk sac fully absorbed, mouth open and fasted. The larvae were subjected to density of 5 (D5), 15 (D15) and 25 (D25) larvas.L-1, in polyethylene boxes (0.63 x 0.45 x 0.32 m) with 20 Litre of water. We used a completely randomized design with four replications. The larvae were fed six times a day, each meal consisting of Artemia in the proportion 50 náuplios.larva-1 (4th to 6th DAH), 100 (7th to 9th DAH), 200 (10th to 11th DAH) and 400 (12th to 13th DAH) and commercial diet ...
Mestre
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Suzuki, Yoshiaki, Teruo Matsubara, Mitsuo Hoshino e 輝男 松原. "Breakdown of mineral grains by earthworms and beetle larvae". Elsevier, 2003. http://hdl.handle.net/2237/5300.
Testo completo
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Morrissey, Barbara. "Epidemiology of Paenibacillus larvae, causative agent of American foulbrood". Thesis, University of York, 2015. http://etheses.whiterose.ac.uk/13766/.
Testo completoAbstract (sommario):
Paenibacillus larvae is the causative agent of American foulbrood (AFB), a damaging disease of honey bees (Apis mellifera) with a global distribution. AFB infects the honey bee larvae through spore-contaminated larval food and once infected the larvae will die within twelve days. AFB infection leads to the eventual death of the honey bee colony. In many countries the best control method is thought to be the destruction of the colony, to destroy the hardy, infectious spores. Therefore infection nearly always leads to the death of the colony. In the UK cases of the disease have decreased in recent years due to statutory control methods, however sporadic outbreaks occur each year. Many advances have been made in our knowledge of the mechanisms of infection by P. larvae in recent years however, a high resolution, standardised method of strain typing is required to track disease spread and understand outbreak sources. This thesis describes the development of the first multilocus sequence typing (MLST) scheme for P. larvae. MLST is the gold standard for pathogenic bacteria typing. It is based on the sequencing of sections of 6-10 housekeeping genes. MLST is standardised, as primer and allele sequences can be made available for other researchers. The new MLST scheme was used to describe previously undetectable patterns of distribution at a global level as well as at a national level. Humans and bees are implicated in the movement of the disease over different spatial scales. Using the MLST scheme a diverse group of isolates were selected for whole genome sequencing. For the first time multiple genomes were compared within and between genotypes. The ability of the MLST scheme to describe relationships amongst sequence types (STs) was tested by comparing phylogenies based on core genes and MLST sequences. I describe the discovery of seven plasmids in four STs previously unknown to harbour plasmids.
40
Robinson, Michael Elden. "Investigation of behaviour changes in parasitized Drosophila melanogaster larvae". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq24233.pdf.
Testo completo
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Caldwell, Lesley Anna. "Intracellular pH and vesicle fusion in Drosophila larvae neurones". Thesis, University of Cambridge, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.610629.
Testo completo
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Garcia, Romero Maria Montserrat. "Molecular and cellular dissection of zebrafish larvae tail regeneration". Thesis, University of Sheffield, 2016. http://etheses.whiterose.ac.uk/15398/.
Testo completoAbstract (sommario):
Regeneration is the ability of organisms to restore their structures in form and function. While it is present in the complete animal kingdom, humans retain the capacity to restore some tissues and organs, but this capacity is limited in comparison with that of other vertebrates such as the zebrafish. Further, the growth of regenerative diseases and the lack of therapies to fully restore damaged organs and limbs highlight the importance of the study of regeneration. To further the understanding of the regeneration process, this study focuses on molecular and cellular dissection of the tail regeneration of zebrafish larvae. The molecular dissection found that the molecular signalling Hedgehog regulates regeneration through the Wnt and Fibroblast Growth Factor (FGF) developmental pathways as follows. The regeneration marker genes msxc, dlx5a and raldh2 are regulated by Hedgehog (Hh) through Wnt signalling, while cell proliferation is regulated by Hh through FGF signalling. Further, the role of Hh during regeneration is unique and different to its role during normal tail development, where it is not essential. Finally, it was found that the muscle differentiation marker myod is expressed sequentially after the regeneration marker genes raldh2 and dlx5a during the late stage of tail restoration. For the cellular dissection cell lineage tracings during regeneration were performed using several Cre expressing lines with tissue specific promoters, where Cre recombination is controlled by 4OH Tamoxifen administration. The lineage tracing analysis showed that both blood vessels and periderm cells participate during tail restoration and that both cell types remain lineage committed. Altogether the results presented in this thesis show that the zebrafish larva tail is a suitable model to study both molecular and cellular aspects of regeneration. The knowledge generated during this PhD research can contribute to set the basis for the development of clinical therapies to assist human regeneration.
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Lundgren, Kristina. "Impact of fly specific bacteria on fly larvae composting". Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-377636.
Testo completoAbstract (sommario):
About one third of all edible food is wasted globally each year. This calls for improvements in resource and waste management. An interesting solution for organic waste is fly larvae composting, which both produces protein in the form of larvae and a nutrient rich residue. The larvae can be used as animal feed while the residue can be applied as an organic fertilizer, thus recycling the nutrients. Fly larvae composting with the black soldier fly (BSF), Hermetia illucens, is relatively new, but there is extensive research on how the treatment is affected by different parameters, e.g. temperature, moisture and type of organic waste that is treated. The role of bacteria has only been the topic of a few studies in recent years but has shown promising positive effects on larval growth. This study investigated the impact of bacteria isolated from BSF eggs on fly larvae composting of food waste by BSF larvae. The study was done in two experimental phases. In phase I, groups of three bacteria were added to each treatment together with the larvae and only single treatments were executed; in phase II triplicates of promising groups of three, two or single bacteria were evaluated. The results of phase I suggested that selected groupings of bacteria could either decrease or increase the bioconversion ratio and in general decrease the reduction ratio of the food waste, while the survival ratio did not seem to be impacted. However, in phase II no significant difference (p<0.05) between the treatments with bacteria and the control were found for any evaluated variables. Interestingly, the variation in resulting bioconversion ratio and reduction ratio (on a VS basis) was found to be reduced when one or more bacteria were present. The coefficient of variation in bioconversion ratio was 9.5% for the control compared to between 2.5% and 6.1% for treatments with bacteria. For the reduction ratio the variation was reduced from 5.6% and to between 0.9% and 4.6% for the bacteria treatments. Hence, seeding with bacteria may improve stability of the process, which is especially interesting when scaling up the process.Globalt slängs ungefär en tredjedel av all ätbar mat. Därmed finns ett stort behov av säker och hållbar avfallshantering. En intressant lösning för organiskt avfall är fluglarvskompostering, som både producerar protein i form av larver och en näringsrik behandlingsrest. Larverna kan exempelvis användas som djurfoder medan behandlings-resten kan användas som gödselmedel, vilket innebär att näring kan återvinnas. Fluglarvskompostering med amerikansk vapenfluga (BSF), Hermetia illucens, är en relativt ny teknik men det finns redan omfattande forskning på hur olika processparametrar, t.ex. temperatur och vattenhalt, påverkar processen. Bakteriers roll har studerats endast i ett fåtal studier men de indikerar att tillsats av bakterier kan ha en positiv inverkan på larvernas tillväxt. Den här studien har därför undersökt hur tillsats av bakterier isolerade från BSF ägg påverkar fluglarvskompostering av matavfall med BSF larver. Studien gjordes i två experimentella delar. I fas I undersöktes effekten av tillsats av bakteriegrupper om tre bakterier till matavfallet samtidigt med larverna; i fas II utfördes triplikat av lovande bakteriegrupper med tre, två eller enstaka bakterier. Resultaten från fas I indikerade att olika bakteriegrupper antingen kunde höja eller sänka bioomvandlingskvoten och generellt gav en minskning i materialreduktions-kvoten medan överlevnadsgraden inte verkade påverkas i samma utsträckning. I fas II observerades däremot ingen signifikant skillnad (p<0,05) mellan någon av bakteriebehandlingarna och kontrollen för samtliga processvariabler. Variationen i resulterande bioomvandlingskvot och materialreduktionskvot (på VS basis) var dock lägre för bakteriebehandlingarna jämfört med kontrollen. Variationen i bioomvandlings-kvot var 9,5% för kontrollen jämfört med 2,5-6,1% för bakteriebehandlingarna. För materialreduktionskvoten minskade variationen från 5,6% till mellan 0,9% och 4,6%. Detta tyder på att tillsats av bakterier kan förbättra stabiliteten hos fluglarvskompostering, vilket är särskilt intressant vid uppskalning av processen.
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Wheeler, Jeanette Danielle. "Behavioral responses of invertebrate larvae to water column cues". Thesis, Massachusetts Institute of Technology, 2016. http://hdl.handle.net/1721.1/103337.
Testo completoAbstract (sommario):
Thesis: Ph. D., Joint Program in Biological Oceanography (Massachusetts Institute of Technology, Department of Biology; and the Woods Hole Oceanographic Institution), 2016.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 139-150).
Many benthic marine invertebrates have two-phase life histories, relying on planktonic larval stages for dispersal and exchange of individuals between adult populations. Historically, larvae were considered passive drifters in prevailing ocean currents. More recently, however, the paradigm has shifted toward active larval behavior mediating transport in the water column. Larvae in the plankton encounter a variety of physical, chemical, and biological cues, and their behavioral responses to these cues may directly impact transport, survival, settlement, and successful recruitment. In this thesis, I investigated the effects of turbulence, light, and conspecific adult exudates on larval swimming behavior. I focused on two invertebrate species of distinct morphologies: the purple urchin Arbacia punctulata, which was studied in pre-settlement planktonic stages, and the Eastern oyster Crassostrea virginica, which was studied in the competent-to-settle larval stage. From this work, I developed a conceptual framework within which larval behavior is understood as being driven simultaneously by external environmental cues and by larval age. As no a priori theory for larval behavior is derivable from first principles, it is only through experimental work that we are able to access behaviors and tie them back to specific environmental triggers. In this work, I studied the behavioral responses of larvae at the individual level, but those dynamics are likely playing out at larger scales in the ocean, impacting population connectivity, community structure, and resilience. In this way, my work represents progress in understanding how the ocean environment and larval behavior couple to influence marine ecological processes.
by Jeanette Danielle Wheeler.
Ph. D.
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Komo, Larissa. "Mechanisms and benefits of heterospecific aggregation in necrophagous larvae". Thesis, Lille 2, 2019. http://www.theses.fr/2019LIL2S046.
Testo completoAbstract (sommario):
Le nécrobiome définit la communauté impliquée dans le processus de décomposition de la biomasse morte (la nécromasse). Cette communauté comprend de nombreux invertébrés et microorganismes différents qui se rassemblent sur des sites spécifiques de la nécromasse. Les mouches à viande jouent un rôle important en tant que premiers organismes décomposeurs, dont les larves (asticots) forment de grandes masses sur les cadavres. Ces regroupements spatial et temporel peuvent être constitués soit d'une espèce (agrégations conspécifiques), soit de plusieurs espèces différentes plus ou moins proches phylogénétiquement (agrégations hétérospécifiques). Cette dernière est supposée aboutir à une relation mutuellement bénéfique, c’est-à-dire entraînant des avantages partagés ne pouvant être obtenus par la seule présence de congénères.Cette thèse s’intéresse aux agrégations hétérospécifiques de trois espèces de Diptères Calliphoridae communes : Calliphora vomitoria, C. vicina et Lucilia sericata. Premièrement, je démontre dans un premier temps que l’agrégation de ces larves résulte de comportements actifs, et notamment de mécanismes de choix en faveur des groupes hétérospécifiques. Deuxièmement, je montre que dans de telles agrégations hétérospécifiques, aucune des deux espèces n'a de désavantages immédiats par rapport à une agrégation conspécifique de même densité en termes de survie, de développement et de taille. Au contraire, des avantages sont obtenus dans au moins un caractère lié à la fitness à des températures en dehors de la gamme optimale de température spécifique à l'espèce. Il est intéressant de noter qu'au sein d'agrégations larvaires hétérospécifiques, l'espèce qui se trouve à une température sous-optimale adapte son développement lent à celui des espèces mieux adaptées. Troisièmement, j'observe que C. vicina avec un développement larvaire rapide pendant la phase d'alimentation se développe plus lentement dans la phase post-alimentation et nymphale (par opposition à L. sericata). Quatrièmement, je démontre qu'un développement accéléré est compensé différemment par les deux espèces. En fait, j'ai observé une concurrence asymétrique, C. vicina étant le concurrent le plus faible. Par exemple, un développement larvaire rapide a entraîné une augmentation de la mortalité pré-adulte et une réduction de la taille des puparia de C. vicina à des températures sous-optimales. En revanche, un développement rapide n'a eu aucune conséquence négative sur la taille et la survie de L. sericata. Cette plasticité développementale peut expliquer le succès évolutif des larves de L. sericata, qui sont présentes dans plusieurs écosystèmes à travers le monde et qui dominent l'écosystème des cadavres frais. Sur cette base, je postule que l'agrégation hétérospécifique des larves de diptères nécrophages est un mécanisme adaptatif facilitant leur succès pré-reproductif dans un environnement particulièrement compétitif et in fine leur fitness.En conclusion, j'ai démontré dans cette thèse des avantages des agrégations hétérospécifiques pour les larves en termes de taille, de survie ou de développement, et surtout, un compromis entre ces caractères. De plus, la pression sélective agit différemment sur les caractères en fonction, parmi d’autres facteurs, de l'espèce, de la composition du groupe et de la température. Enfin, ces résultats n’ont pas seulement un intérêt écologique, mais également applicatif. L'entomologie médico-légale utilise en effet ces larves pour dater le décès. Les conclusions de cette thèse indiquent que la taille et la composition des groupes larvaires peuvent constituer une source d’erreur pour le calcul de l’intervalle post-mortem minimumThe necrobiome defines the community that is involved in the decomposition process of dead biomass (i.e., necromass). This community includes many different invertebrates and microorganisms that gather on specific sites of the necromass. Blowflies take on an important function as the primary and first digesters, whose larvae form large maggot-masses. Such spatial and temporal groupings can either consist of one species (i.e., conspecific aggregations) or of several different species more or less phylogenetically related (i.e., heterospecific aggregations). The latter is supposed to lead to a mutually beneficial relationship entailing benefits that are not apparent in conspecific aggregations.This thesis focuses on heterospecific aggregations of three common Calliphoridae (Diptera) species: Calliphora vomitoria, C. vicina and Lucilia sericata. First, I demonstrate that the aggregation of larvae results from active behaviours and, in particular, from choice mechanisms favouring heterospecific groups. Second, I show that in such heterospecific aggregations none of the two species has short-term costs compared to a conspecific group of the same density regarding survival, larval development rate and puparium surface area. On the contrary, benefits are achieved in at least one fitness-related trait at temperatures outside the species-specific optimal range. Interestingly, within heterospecific larval aggregations, the species that finds itself at a suboptimal temperature adapts its slow development rate to that of the better-adapted species. Third, I illustrate that C. vicina with a fast larval development during the feeding phase developed slower in the postfeeding and intra-puparial phase (in contrast to L. sericata). Fourth, I demonstrate that an accelerated development is compensated differently by the two species. In fact, I observed an asymmetric competition with C. vicina being the weaker competitor. For example, fast larval development led to increased preadult mortality and small C. vicina pupae at suboptimal temperatures. In contrast, fast development had no negative consequences on size and survival for L. sericata. This developmental plasticity may explain the evolutionary success of L. sericata larvae, which are present in several ecosystems worldwide and dominate the fresh-carrion ecosystem. On this basis, I postulate that heterospecific aggregation in necrophagous Diptera larvae is an adaptive mechanism that increases their pre-reproductive success and, ultimately, their fitness in a particularly competitive environment.In conclusion, I established benefits for larvae in heterospecific aggregations in terms of their surface area, survival or developmental rate, and most importantly, a trade-off between these traits. Moreover, selection pressure acts differently on the traits depending, among other factors, on species, group composition and temperature. Finally, these results are not only of ecological importance, but also have consequences in the field of forensic entomology. Indeed, these larvae are used to estimate the time of death. Therefore, the present findings indicate that the density and composition of larval groups can be a source of error in estimating the minimum post-mortem interval
46
McLellan, Christopher Richard. "Statistical modelling of home range and larvae movement data". Thesis, University of Edinburgh, 2014. http://hdl.handle.net/1842/14202.
Testo completoAbstract (sommario):
In this thesis, we investigate two di erent approaches to animal movement modelling; nite mixture models, and di usion processes. These models are considered in two di erent contexts, rstly for analysis of data obtained in home range studies, and then, on a much smaller scale, modelling the movements of larvae. We consider the application of mixture models to home range movement data, and compare their performance with kernel density estimators commonly used for this purpose. Mixtures of bivariate normal distributions and bivariate t distributions are considered, and the latter are found to be good models for simulated and real movement data. The mixtures of bivariate t distributions are shown to provide a robust parametric approach. Subsequently, we investigate several measures of overlap for assessing site delity in home range data. Di usion processes for home range data are considered to model the tracks of animals. In particular, we apply models based on a bivariate Ornstein-Uhlenbeck process to recorded coyote movements. We then study modelling in a di erent application area involving tracks. Di usion models for the movements of larvae are used to investigate their behaviour when exposed to chemical compounds in a scienti c study. We nd that the tted models represent the movements of the larvae well, and correctly distinguish between the behaviour of larvae exposed to attractant and repellent compounds. Mixtures of di usion processes and Hidden Markov models provide more exible alternatives to single di usion processes, and are found to improve upon them considerably. A Hidden Markov model with 4 states is determined to be optimal, with states accounting for directed movement, localized movement and stationary observations. Models incorporating higherorder dependence are investigated, but are found to be less e ective than the use of multiple states for modelling the larvae movements.
47
Gibbs, Mitchell. "The impact of climate change on larvae of oysters". Thesis, The University of Sydney, 2020. https://hdl.handle.net/2123/24912.
Testo completoAbstract (sommario):
Marine larvae are a critical life history stage of marine molluscs which will be impacted by climate change. There is a pressing need to understand whether marine molluscs will have the capacity to adapt and persist in this era of rapid change. Transgenerational plasticity is a mechanism for rapid acclimation of marine organisms which result in resilient offspring when exposed to climate change. The overall aim of this thesis was to determine the impact of climate change on the larvae of the native Sydney rock oyster, Saccostrea glomerata and invasive Pacific oyster Magallana gigas. The main hypothesis tested was that whether responses of larvae would be improved through transgenerational exposure to climate change stress including warming and elevated pCO2CO2 on the morphological, physiological and lipid energetics.
The experiments in this thesis showed that the larvae of M. gigas may be more robust than the larvae of S. glomerata when exposed to near future climate change conditions, however, S. glomerata may have a greater scope for transgenerational plasticity to cope with a changing climate. This thesis supports the idea that although transgenerational parental conditioning has been suggested as an acclimatory mechanism for marine organisms to cope with the stress of climate change it may not equally be a panacea to all conditions for all oyster species. This thesis has also demonstrated that larval mortality is not likely due to the expiration of lipid reserves when starved or exposed to warming and acidification. The findings of this thesis suggest that the dynamic between the native S. glomerata and invasive M. gigas may be altered as estuarine change in South eastern Australia accelerates. These findings will inform the global bivalve aquaculture industry worth $44 million to the state of New South Wales and $50 billion to the globe, which is at risk due to global climate change.
48
Neira, Francisco Javier. "Systematics and ecology of larvae of lampreys and fishes". Thesis, Neira, Francisco Javier (1988) Systematics and ecology of larvae of lampreys and fishes. PhD thesis, Murdoch University, 1988. https://researchrepository.murdoch.edu.au/id/eprint/53025/.
Testo completoAbstract (sommario):
Body intervals, number of trunk myomeres and frequency of pigmentation in different body regions were recorded for populations of larvae of each of the three Southern Hemisphere anadromous parasitic lampreys collected from rivers in Australia, New Zealand and South America. In order to correct for growth, the morphometric data were subjected to multiple group principal components analysis (MGPCA). The components, together with myomere counts and pigmentation data, were subjected to discriminant analyses. Clustering of the discriminant centroids clearly distinguished between populations of Mordacia lapicida from Chile and those of Mordacia mordax from south-eastern Australia. Comparable analyses for Geotria australis suggest that during their marine trophic phase, the adults of this species originating from Argentina and Chile follow different migratory routes, whereas those from Western Australia, New Zealand and Tasmania intermix.
A total of 65,253 larval fish, representing 36 families and 70 species, were collected from surface waters throughout the Swan Estuary between January 1986 and April 1987. Density of many of the most abundant species reached a peak between November and January. The most abundant families were the Gobiidae (88.5%), Clupeidae (3. 5%), Engraulidae (2.3%) and Blenniidae (1.0%). The abundance and distribution of larvae of Nematalosa vlaminghi, Engraulis australis, Parablennius basmanianus, Urocampus carinirosbris, Apoqon rueppellii Atherinosoma wallacei and Amniataba caudavittatus indicate that these species spawn in the upper and/or middle estuary, whereas species such as Hyperlophus vittatus, Parapercis haackei, Callionymus qoodladi and Pelates sexlineabus typically spawn in the lower estuary. Larvae in the lower estuary belonged predominantly to marine species (60%) whose adults are infrequently found in the estuary and to those species which use estuaries and inshore-marine areas as nurseries (21.4%). Although the larvae in the middle and upper estuary represented a small number of species which typically breed within the estuary (14.3%), they accounted for 91.1% of all larvae caught in the estuary. While number of species, diversity and evenness decreased with distance from estuary mouth, the density of larvae was greatest in the upper estuary. The relationships between the above community variables and environmental variables are discussed.
Studies on the early life history of five species from the Swan Estuary indicate that the development of larval Atherinosoma wallacei, Ammniataba caudavitattus and Apogon rueppellii takes place predominantly in the upper estuary between mid-spring and early autumn, whereas that of Gymnapistes marmoratus and Lesueurina sp. occurs in the lower estuary between winter and early spring. While the larvae of all these species are pelagic, they show a variety of developmental and morphological characters which may facilitate their survival and retention within the estuary. These include a large swim bladder and dark body pigment (A. wallacei), extensive head spination and early development of large pectoral fins (G. marmoratus), rapid settlement (A. caudavittatus and G. marmoratus), an advanced stage of development at hatching (A. rueppellii) and an elongated body (Lesueurina sp.).
49
Candeias, Adriana Tojinha. "Feeding, swimming and respiration in barnacle larvae (Cirripedia: Thoracica)". Thesis, Bangor University, 2006. https://research.bangor.ac.uk/portal/en/theses/feeding-swimming-and-respiration-in-barnacle-larvae-cirripedia-thoracica(fa95c21c-28dd-4d89-a617-8d1a12e41045).html.
Testo completoAbstract (sommario):
For planktotrophic larvae, the availability of food is one of the major factors thatcontrol growth and development. In the present study, feeding and starvation were investigated within the scope of survival, swimming and respiration rates of Cirripedialarvae. Adults of Pollicipes pollicipes (Pedunculata: Scalpellidae) and Elminius modestus(Sessilia: Balanidae) were collected from the Iberian Peninsula and western UK coast, respectively, and a series of laboratory experiments conducted using a novel rotating wheel immersed in a temperature controlled tank. Observations were made on larval growth, gut size, mobility and oxygen consumption in response to both the supply of food in the form of controlled algal sources, as well as starvation conditions. Resulting data were analysed and revealed notable trends in the relationship between the different functional outputs at different stages of development, up to and including the cyprid. Mono- and mixed algal cultures were tested, confirming that both barnacle species have geographical related dietary preferences. Size of algal cells was only one of the factors associated with feeding rates, while volume densities and quality of the supplied phytoplankton proved of substantial importance throughout the whole study. Under starvation conditions, swimming performance did not deteriorate during 28 hours after hatching, indicating that E. modestus nauplius II carry enough yolk reserves to proceed the search for food. Nonetheless, oxygen consumption reduced after 8 hours indicating that larvae are able to adjust their metabolism as an energy conservation strategy. This would account for the oceanic distribution of spawned larvae even under conditions of impoverished plankton supply. Increase in oxygen consumption in earlier larval stages is associated with high energy expenditure of swimming and capture of food, while during the metanauplii, stable weight specific respiration rate accompanied by reduced swimming speeds suggests an increase in non-swimming related metabolic activity, possibly reflecting a radical physiological and functional shift at this stage. The first demonstration of specific dynamic action in barnacle larvae is discussed. The details provided on specific feeding rates and development, algal preference, physiological processes and swimming behaviour of barnacle larvae, contribute to the understanding of the effect of barnacles on the phytoplankton while part of the meroplankton communities.
50
D'Souza, Frances M. L. "The nutritional value of microalgae to penaeid prawn larvae". Thesis, Queensland University of Technology, 1997. https://eprints.qut.edu.au/36935/1/36935_Digitised%20Thesis.pdf.
Testo completoAbstract (sommario):
This is the first study to investigate the nutritional requirements of the penaeid prawn protozoeal phase (the first feeding stage of the prawn life cycle) using micro algae to provide different nutritional conditions.
The work was a simultaneous examination of the biochemical
composition of the larvae and their microalgal diets. In addition, the influence of naupliar composition on later larval stages was studied. The biochemical parameters measured were total protein, lipid and carbohydrate (i.e. gross biochemical composition) and total lipid was further resolved into individual fatty acids.
The nutritional requirements of penaeid prawn larvae were assessed by measuring the survival, development (metamorphosis) and growth (in terms of dry weight) of larvae in response to various algal diets. In
this way differences in survival, development and growth could be related to biochemical differences in the algal diets and associated larval body composition.
The changes in biochemical composition of *Penaeus japonicus* and *P. monodon* larvae during metamorphosis from nauplii to protozoea 1 (PZl) and the time course of these changes during starvation and feeding for the ~42 h period that the PZl stage lasts, were examined. The larvae utilised lipid as a major energy source during metamorphosis. The fatty acid fraction of the lipid in nauplii was high
(60 to 80%) compared with protozoeae (30 to 60%) and provided a large proportion of the energy required for metamorphosis. Of the total fatty acids, the monounsaturated (MUFAs) and saturated fatty
acids contributed most of this energy. During starvation the MUFAs and polyunsaturated fatty acids (PUPAs) were metabolised while the highly unsaturated fatty acids (HUFAs) were conserved, presumably because of their role as structural components in cell membranes. The
PUFA linoleic acid (18:2n-6) appeared to have a role as a component of cell membranes when in short supply, but it accumulated as an energy reserve when in excess in the diet. Linolenic acid (18:3n-3) was actively metabolised to other membrane fatty acids or used for energy.
The effect of altering the biochemical composition of the microalga
*Tetraselmis suecica* on *P. semisulcatus* larvae was studied by reducing the nitrate concentration from -1760 μ*M* to 176 μ*M* in the culture media. Carbohydrate increased three fold in the low nitrate algae, and protein and lipid were reduced slightly compared to the control. The
low protein:energy ratio (0.1 to 0.2) of the low nitrate diets resulted in a delay in the development of the larvae compared to that of the animals fed the control diet (ratio 0.3 to 0.4). Survival was not affected by the algal diets.
Four species of algae (*Tetraselmis suecica*, *Chaetoceros muelleri*, Tahitian *Isochrysis* sp. (T-iso) and *Dunaliella tertiolecta*) differing predominantly in their fatty acid composition were fed to *P. japonicas* larvae as single species diets. The two best diets (in terms of growth
and survival of the prawn larvae) were subsequently fed in combination to *P. semisulcatus* and *P. monodon* larvae to assess their nutritional value as part of a mixed diet. The survival and development to mysis 1 (M1), i.e. performance, of the larvae was affected by the algal diets
such that the diets could be ranked: *C. muelleri* > *T. suecica* > *Isochrysis* sp. (T-iso) > *D. tertiolecta*. The fatty acid profiles of the algae, particularly those of arachidonic acid (20:4n-6) and eicosapentaenoic acid (20:5n-6), were related to those of the larvae and
their performance. The presence of both of these fatty acids in the algal diet was necessary to produce high performance whereas docosahexaenoic acid (22:6n-3) was not. The low requirements for the PUPAs 18:2n-6 and 18:3n-3 were modulated by the presence of HUFAs such as 20:4n-6, 20:5n-6 and 22:6n-3. Therefore when these HUFAs were present in the diet, less 18:2n-6 and 18:3n-3 were required. However high proportions of 18:2n-6 and 18:3n-3 alone, did not
replace the requirements for 20:4n-6, 20:5n-6 and 22:6n-3.
Understanding the nutritional requirements of penaeid prawn larvae will lead to the production of a cost effective and optimum diet for use in hatcheries. In addition, this research will contribute to the production of a purified artificial diet for penaeid prawn larvae which can be used to examine the requirements for other nutrients.