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1
Stevens, Peter M. (Peter Michael). "Host races and cryptic species in marine symbionts." Thesis, University of Auckland, 1990. http://hdl.handle.net/2292/2321.
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The Pinnotheridae is a family of decapod crustaceans comprising more than 120 mostly microphagous and commensal species. As symbionts of a variety of aquatic invertebrates, pinnotherids typically live in an intimate association with their host depending on it for an almost lifelong source of nourishment and shelter, together with a site for mating. The New Zealand pinnotherid fauna was thought to comprise only one species, Pinnotheres novaezelandiae Filhol, associated with a multitude of hosts. Recently, however, a separate species, P. atrinicola Page, has been described which is regarded as being host specific to the horse mussel Atrina zelandica Gray. In this context, the relationship between pea crabs and their hosts is of special interest, and is the focus of this thesis. An investigation into the population dynamics of the symbiotic relationship between P novaezelandiae and its host, the green-lip mussel Perna canaliculus, at Westmere Reef, Auckland between May 1986 and July 1988 is reported. Ovigerous females and Stage I males and females were found throughout the sampling period, indicating that reproduction is continuous in this species. The developmental composition of the pea crab population reveals that soft-shelled males, usually regarded as an anomalous instar, formed a significant component of the pea crab population at all times. It is suggested that these individuals represent a distinct facies, analogous to the Stage II female instar. The presence of a pea crab was found to have a highly significant detrimental effect on mussel condition. Analysis of the distribution of pea crabs among the mussel population indicates mature crabs display a repulsed distribution favouring to live a solitary existence, whereas younger (pre-hard and Stage I) crabs showed a random distribution in broad agreement with a theoretical Poisson distribution. The biological status of the two described taxa was investigated by a survey of electrophoretically detectable genetic variation of populations from throughout the North Island of New Zealand. Pea crabs from 18 host populations from nine geographically disparate localities were subjected to cellulose acetate and poly-acrylamide electrophoresis. Forty-one enzyme systems were screened for polymorphism. Clearly resolved enzyme phenotypes were obtained at 23 presumptive loci, of which l5 exhibited polymorphism. An analysis of electromorph frequency data revealed that both taxa are highly genetically structured and typified by high levels of polymorphism and heterozygosity; results atypical of brachyuran crabs. P- atrinicola was found to exhibit strong patterns of geographic differentiation and clinal variation in electromorph frequency. Of particular significance is the pattern of genetic differentiation observed among populations of p. novaezelandiae. Hierarchical F-statistics indicated that the preponderance of inter-population differentiation can be attributed to differences in electromorph frequency among host-associated populations of P. novaezelandiae within a sampling locality. Geographic differentiation was a comparatively insignificant factor in the structuring of the sampled P. novaezelandiae populations. Individuals belonging to two genetically very distinct units were found within a newly recorded host species, Mactra ovata ovata Gray at Green and Wood Bays, Manukau Harbour. Hardy-Weinberg analyses indicate the host-associated populations of P. novaezelandiae exhibit such a pronounced pattern of homozygote excess and disturbance from genetic equilibrium in sympatry that it is unreasonable to consider them as a single panmictic population. It is concluded that significant biological discontinuities based on host origin exist within the currently recognised taxon. Such a conclusion is supported by data presented on qualitative differences in host recognition observed between different host-associated populations of P. novaezelandiae. Conservatively these discontinuities indicate host race development, although a viable alternate hypothesis would be the presence of cryptic, host-specific biological species within P. novaezelandiae. Hostrace development as found here is a well recognised phenomenon in insect-host and parasitoid-host relationships, although little studied in marine symbiotic relationships. Such a phenomenon has important implications for ecological, behavioural and physiological studies on marine symbionts in general.
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Stevens, Peter M. "Host races and cryptic species in marine symbionts." Connect to this title online, 1990. http://hdl.handle.net/2292/2321.
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Barlow, Katherine Elisabeth. "Resource partitioning between two cryptic species of Pipistrellus." Thesis, University of Bristol, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.361107.
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Talbot, Jessica Jane. "Common and cryptic Aspergillus species – one health pathogens." Thesis, The University of Sydney, 2018. http://hdl.handle.net/2123/19930.
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Fungal Aspergillus species cause invasive and chronic disease in humans and other animals. This thesis investigated cryptic and common Aspergillus species in A. section Fumigati; their prevalence in Australia and virulence factors impacting the efficacy of the most commonly used antifungal drugs, triazoles. An environmental (soil and air) investigation of 104 Aspergillus isolates for cryptic A. sect. Fumigati species, focusing on the A. viridinutans species complex (AVSC), found a moderate risk of exposure to known pathogenic and cryptic species, but low risk AVSC exposure in indoor and outdoor domestic environments. A new AVSC species was discovered, A. frankstonensis (morphology; ITS region, BenA, CalM, MCM7, actin and RPB2 gene sequencing; antifungal susceptibility; and extrolite analysis are described). Sequencing (ITS, BenA) of clinical isolates from captive birds (n=30) identified A. fumigatus as the most common cause of disease and A. restrictus as pathogenic. Triazole resistance amongst A. fumigatus isolates from clinical and environmental samples is documented over two studies, identifying a low prevalence in Australia. The first investigated pathogenic A. fumigatus isolates from dogs and cats (n=50), finding triazole resistance in one Australian isolate from a dog in the early 1990’s (Sensititre™ YeastOne™YO8). The second investigated clinical (148 human, 21 veterinary) and environmental (n=185) Australian isolates (VIPcheck™ and Sensititre™ YeastOne™ YO10), confirming triazole resistance in three human origin isolates, associated with cyp51A mutations TR34/L98H and G54R. Triazole susceptibility (CLSI) of 37 AVSC isolates were investigated, detecting high triazole minimum inhibitory concentrations (84% of isolates). Compared to wild-type A. fumigatus, high rates of cyp51A mutations were detected on sequencing; however protein homology modelling did not confer resistance. This research informs our understanding of A. sect. Fumigati pathogens in Australia.
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Fourie, Arista. "Distinguishing between cryptic species in the Ceratocystis fimbriata sensu lato species complex." Diss., University of Pretoria, 2014. http://hdl.handle.net/2263/62102.
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Witt, Jonathan. "Cryptic amphipod species in the Laurentian Great Lakes Basin." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ35946.pdf.
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Mrinalini, ? "Species delimitation and identification in morphologically cryptic Asian pit vipers." Thesis, Bangor University, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.540404.
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Monis, Paul T. "Molecular systematics of the protozoan parasite Giardia intestinalis : identification of cryptic species /." Title page, contents and abstract only, 1997. http://web4.library.adelaide.edu.au/theses/09PH/09phm744.pdf.
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Moeser, Andrew A. "Genetic analyses of sympatric cryptic species in the Neotropical catfish, Pimelodella chagresi." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=82294.
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I used microsatellite markers to assess reproductive isolation between cryptic, sympatric lineages of a freshwater catfish (Pimelodella chagresi ). These are "cryptic" lineages because they cannot be distinguished visually on the basis of morphological characters, and currently they are recognized as a single species. Previous analyses utilizing mitochondrial DNA (mtDNA) indicated that two highly divergent lineages are present in lower Central America, and that these lineages are the result of independent colonization events from South American source populations. I isolated eight dinucleotide repeats from P. chagresi and designed primers to amplify these microsatellite loci. I sampled fishes from four Panamanian watersheds. The congruence of microsatellite data with mtDNA indicated that these taxa are reproductively isolated and should be considered as separate species despite the lack of morphological differentiation. Both lineages exhibit a high degree of divergence among populations inhabiting isolated freshwater drainages, but the lineages differ in their intra-watershed population structure.
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Scriven, Jessica J. "The ecology and population genetics of a complex of cryptic bumblebee species." Thesis, University of Stirling, 2016. http://hdl.handle.net/1893/24771.
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Bumblebees are ecologically and economically important as pollinators, but some species are suffering severe declines and range contractions. In this thesis, three cryptic bumblebee species are studied to elucidate differences in their distribution, ecology and population genetics. As a result of their high morphological similarity, very little is known about the lucorum complex species: B. lucorum, B, cryptarum and B. magnus. In this study, their distributions across Great Britain were assessed using molecular methods, revealing that B. lucorum was the most abundant and most generalist of the three species, whereas B. magnus was the rarest and most specialised, occurring almost exclusively on heathland. Additionally, both B. magnus and B. cryptarum were more likely to be present at sites with cooler summer temperatures. Cryptic species represent interesting models to investigate the levels of niche differentiation required to avoid competitive exclusion. Characterising the niches of these species at a single site across the flight season revealed differences along three niche dimensions: temporal activity, weather sensitivity and forage-resource use. These species exhibited asymmetric niche overlap; a combination of ecological divergence and spatio-temporal heterogeneity may contribute to maintaining them in sympatry. Population genetic studies can be highly informative for understanding species ecology and for conservation management. The differences in habitat specialisation exhibited by these bumblebee species provide the opportunity to test conflicting hypotheses about links between dispersal and ecological specialisation: are habitat specialists selected to have low or high dispersal ability? Based on microsatellite analysis, the generalist B. lucorum had high levels of genetic diversity and little population structure across large spatial scales. The habitat specialist B. magnus had the lowest genetic diversity but similar levels of population differentiation to the moderate generalist, B. cryptarum. However, unlike B. cryptarum, B. magnus population differentiation was not affected by geographic distance, suggesting that this specialist species may maintain effective dispersal across large scales despite being restricted to a fragmented habitat. Bergmann’s rule is a well-known ecogeographic rule describing geographical patterns of body size variation, whereby larger endothermic species are found more commonly at higher latitudes. Ectotherms, including insects, have been suggested to follow converse Bergmann’s gradients, but the facultatively endothermic nature of bumblebees makes it unclear which pattern they should adhere to. This thesis reports caste-specific differences in body size between the three lucorum complex species in agreement with Bergmann’s rule: queens and males of B. cryptarum and B. magnus, which were found more commonly at higher latitudes and at sites with cooler temperatures, were larger than those of B. lucorum. Population genetic studies of invertebrates generally require the destruction of large numbers of individuals, which is often undesirable. Testing a variety of faecal collection and DNA extraction methods demonstrated that it is possible to obtain DNA of sufficient quality for genotyping from bumblebee faeces, without harming the individuals. This method would be valuable for studies of rare or declining bee species, for queens in reintroduction projects, and may be applicable to other arthropods. Overall this thesis contributes substantially to our knowledge of the ecology and population genetics of three important pollinator species. It provides data to inform species conservation, as well as understanding of ecosystem functioning and population dynamics. Furthermore, it successfully uses these cryptic species as a model to test several fundamental ecological theories.
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McLeish, Michael John, and mcleish@sanbi org. "EVOLUTIONARY DIVERSIFICATION OF AUSTRALIAN GALL-INDUCING THRIPS." Flinders University. Biological Sciences, 2007. http://catalogue.flinders.edu.au./local/adt/public/adt-SFU20070926.173412.
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This work further elucidates processes involved in promoting and
sustaining evolutionary diversification within the gall-inducing thrips
that specialise on Australian Acacia. A phylogenetic approach was taken
to determine modes of diversification available to these insects. The
extension and revision of the gall-thrips phylogeny is central to the
work and primarily focuses on cryptic populations of the Kladothrips
rugosus and Kladothrips waterhousei species complexes. Parallel
diversification, where the radiation of the K. rugosus and K.
waterhousei lineages broadly mirror one another, offered a rare
opportunity to test hypotheses of coevolution between gall-thrips and
their Acacia hosts. In the absence of a reliable host Acacia phylogeny,
indirect inference of insect/plant cospeciation can be arrived at as
these two complexes share the same set of host species. The expectation
is that if the phylogenies for the gall-thrips complexes show a
significant level of concordance, then cospeciation between insect and
host-plant can be inferred. Results indicate that the K. rugosus species
complex comprise populations at species level. A significant level of
phylogenetic concordance between the two species complexes is consistent
with gall-thrips lineages tracking the diversification of their Acacia
hosts. Given the less than strict form of insect/host cospeciation,
factors impacting host diversification become important to gall-thrips
diversification. Gall-thrips radiated over a period during the expansion
of the Australian arid-zone. Cycles of host range expansion and
fragmentation during the Quaternary could have played a major role in
gall-thrips diversity. An interesting feature of resourse sharing
amongst the K. rugosus and K. waterhousei complex members is the
apparent absence of competitive exclusion between them. The persistence
of this sympatry over millions of years is an unusual feature and merits
further investigation.
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Carvajal, Campos Amaranta. "Characterization of Aspergillus section Flavi : molecular markers as tools to unmask cryptic species." Thesis, Toulouse 3, 2018. http://www.theses.fr/2018TOU30036/document.
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Certains champignons, notamment des Ascomycètes, peuvent synthétiser des métabolites secondaires toxiques pour les hommes et les vertébrés, appelés mycotoxines. Étant donné que la présence de ces champignons dans les aliments de base constitue un risque potentiel pour la santé humaine et animale, les aliments de base sont éliminés lorsqu'ils sont contaminés. La section Flavi est un des groupes de champignons les plus importants du point de vue économique et sanitaire car il comprend des espèces productrices de mycotoxines. Parmi les mycotoxines produites par ce groupe se trouvent les aflatoxines (AF), considérées comme une préoccupation majeure en raison de leurs effets délétères chez les vertébrés. Les espèces de la section Flavi se développent principalement dans les régions tropicales et subtropicales car elles bénéficient de conditions environnementales optimales. De plus, les conditions de récolte et de stockage sont souvent inappropriées, favorisant ainsi leur développement. Dans les régions tempérées, ces espèces se rencontrent moins fréquemment. Cependant, le réchauffement climatique pourrait favoriser leur colonisation. L'identification des espèces d'Aspergillus de la section Flavi est un défi, en raison de l'inter- et intra-variabilité des caractères. Par conséquent, l'utilisation d'une seule méthode d'identification (caractérisation morphologique, moléculaire ou du profil des métabolites secondaires) est insuffisante. Inversement, le développement d'outils moléculaires a facilité la tâche. Le but de notre étude était de déterminer les relations entre les espèces d'Aspergillus de la section Flavi à partir de différents marqueurs moléculaires (ITS, benA, cmdA, amdS, préA, perB, ppgA, aflP, gènes Mat1), puis d'identifier ceux qui permettent une classification des espèces par inférence phylogénétique. L'utilisation de l'inférence phylogénétique dans cette étude a montré qu'il s'agit d'une approche robuste pour identifier les espèces d'Aspergillus de la section Flavi, notamment en confirmant certaines hypothèses déjà proposées pour les espèces de la section Flavi. En effet, l'ajout de marqueurs moléculaires a permis de confirmer le placement phylogénétique des espèces dans la section Flavi. De plus, une nouvelle espèce cryptique a pu être décrite : Aspergillus korhogoensis (appartenant au clade A. flavus). Notre étude a également pu mettre en évidence que les marqueurs moléculaires sélectionnés (benA, cmdA, mcm7, rpb1, preB, preA et ppgA) sont de bons candidats pour l'étude d'autres sections d'Aspergillus. L'utilisation de l'inférence phylogénétique est une méthode élégante permettant d'identifier de façon précise les espèces. Sur la base de nos résultats, il est recommandé d'utiliser des matrices concaténées pour effectuer une inférence phylogénétique dans cette section, et la meilleure combinaison inclut les gènes benA, cmdA, et l'inclusion d'un autre gène : mcm7, rpb1, preB, preA ou ppgA. A l'inverse, l'utilisation du gène ITS chez Aspergillus peut conduire à une sous-estimation de la diversité car le gène est très fortement conservé. L'étude des gènes du loci Mat1 dans la section est utile pour accroître les connaissances sur la reproduction sexuée chez les ascomycètes. De plus, plusieurs fonctions de la machinerie biologique fongique sont liées aux gènes du loci Mat1. La caractérisation du profil métabolique secondaire chez les souches d'Aspergillus de la section Flavi doit être utilisée, non seulement comme outil d'identification, mais également pour discriminer les souches toxinogènes et atoxinogènes. La section Flavi renferme des espèces capables de produire à la fois de mycotoxines et de composés bénéfiques. Parmi les mycotoxines qui devraient faire l'objet d'une attention particulière figurent les AF, l'acide cyclopiazonique, les versicolorines a et b, la stérigmatocystine. Une étude plus approfondie du métabolisme secondaire sera également utile pour la recherche de nouveaux composés bénéfiquesSome fungi, mostly Ascomycota, are able to synthesize secondary metabolites that are toxic to humans and vertebrates, called mycotoxins. Since the presence of these fungi in staples represents a potential risk to human and livestock health, staples are eliminated when they are contaminated. The section Flavi is one most important group of fungi from an economic and public health point of view because it comprises several mycotoxin producer species. Amongst the mycotoxins produced by this group are aflatoxins (AFs), considered a main concern because of their deleterious effects on humans and vertebrates. Species from section Flavi grow mainly in tropical and subtropical regions where environmental conditions are optimal, and harvest and storage conditions are not always appropriate to avoid production of mycotoxins, which enhance their growth. In temperate regions, these species are less frequent; however, climate changes can favor their colonization. Species identification in Aspergillus section Flavi is challenging because of inter- and intra- variability of traits. Therefore, the use of one identification method (morphological, molecular or secondary metabolite profile characterization) is futile. Conversely, the development of molecular tools has facilitated the task. The aim of this study was to screen the species relationships in Aspergillus section Flavi based on different molecular markers (ITS, benA, cmdA, amdS, preA, preB, ppgA, aflP, Mat1 genes), and subsequently identify which ones allow a fine species classification in the section Flavi by phylogenetic inference. The use of phylogenetic inference in the present study showed that it is a robust approach to identify Aspergillus section Flavi species. The use of this technique confirmed some of the hypotheses proposed in the Flavi section, since more genetic information was added, thus strengthening the placement of the species in the Flavi section. In addition, we described a new cryptic species in this section Aspergillus korhogoensis that is nested in A. flavus clade as the sister taxon of A. parvisclerotigenus. Likewise, the molecular markers (benA, cmdA, mcm7, rpb1, preB, preA or ppgA) were good candidates for studying other sections in Aspergillus. The use of phylogenetic inference is a good method for fine-scale species identification; however, it should be used carefully, and the morphological approach and characterization of secondary metabolites should also be carried out. Based on our results, concatenated matrices are recommended to perform phylogenetic inference in this section, and the best combination includes benA, cmdA, and the inclusion of at least one another gene (preB, mcm7, rpb1, preA or ppgA). Conversely, the use of ITS in Aspergillus may lead to an underestimation of the diversity because the gene is highly conserved. Studying mating type MAT1 loci in the section is helpful to increase the knowledge of sexual reproduction in ascomycetes. In addition, several functions of fungal biological machinery are linked to Mat1 loci genes. Secondary metabolic profile characterization of Aspergillus section Flavi strains should be performed, not only as an identification tool, but also to discriminate toxinogenic and atoxinogenic strains. Section Flavi encloses species able to produce a mixture of mycotoxins and beneficial compounds. Amongst mycotoxins that should be screened are AFs, cyclopiazonic acid, A and B versicolorin, sterigmatocystin, tenuazonic acid. An exhaustive study of the secondary metabolism can also be useful to investigate novel beneficial products
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Kieswetter, Charles M. "Cryptic diversity, landscape genetics and diversification in the Pristimantis w-nigram species complex." Thesis, Boston University, 2012. https://hdl.handle.net/2144/31578.
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Thesis (Ph.D.)--Boston UniversityPLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.
Neotropical montane forests of the Ecuadorian Andes harbor a disproportionate amount of global biodiversity, yet the ecological and evolutionary processes that generate and sustain this diversity are poorly known. Determining the relative roles of historical vicariance, natural selection and genetic drift in generating diversity are active areas of investigation, but no clear pattern has emerged. My research focuses on a direct developing cloud forest frog ( Pristimantis w-nigrum ) found along the Eastern and Western versants of the Ecuadorian Andes. By integrating morphological data, multi-locus sequence data and geographic and environmental data, I demonstrate that: (1) Pristimantis w-nigrum harbors substantial genetic diversity, despite morphological stasis, and may comprise a species complex; (2) Genetic differentiation of mitochondrial DNA identifies eight divergent lineages and highly structured populations along both eastern and western slopes of the Ecuadorian Andes; (3) Multiple nuclear markers show lesser but still substantial population structure; (4) Isolation by distance best explains the pattern of genetic variation, but temperature and precipitation also contribute to genetic and morphological variation; (5) The timing of genetic divergence among mtDNA lineages coincides with sequential paleogeological bouts of Andean orogenesis during the late Miocene and early Pliocene, with terminal lineages diverging during the Pleistocene; (6) Populations have experienced little or no gene flow. (7) Those on the Western slope have maintained large effective population sizes, while populations on the Eastern slope appear to have suffered severe bottlenecks. Taken together, these results suggest a long sequential history of vicariance following the orogeny of the Northern Andes and that allopatric speciation may be a common mode of divergence in montane ectothermic vertebrates with low vagility. In addition, estimation of the species phylogeny and historical and contemporary demographic parameters using multiple loci highlight the utility of a multi-locus approach, particularly in cases where diversification may have occurred relatively recently. The identification of cryptic diversity in the P. w-nigrum suggests that evolutionary processes of isolation and divergence are occurring in the Andes and that the Andes may be an important generator of new species as well as a repository of high biodiversity.
2031-01-01
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Nestler, Jennifer Halin. "A geometric morphometric analysis of Crocodylus Niloticus: evidence for a cryptic species complex." Thesis, University of Iowa, 2012. https://ir.uiowa.edu/etd/3359.
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The Nile crocodile Crocodylus niloticus currently has an extensive range throughout the African continent and Madagascar, though fossil and subfossil remains show that its historic range was considerably larger and included parts of the Sahara Desert, Mediterranean coast, and Arabian Peninsula. Recent molecular studies have yielded genetically distinct populations of C. niloticus, leading to the possibility that C. niloticus is actually multiple cryptic species, while morphological variation remains unassessed. This study compares skulls of C. niloticus to other members of the genus Crocodylus in dorsal view using geometric morphometrics to evaluate intraspecific and interspecific variation. The morphometric analysis is coupled with a geographic analysis to determine if the species is morphologically variable by geographic region as well as a model-based cluster analysis to determine and morphological clusters irrespective of other factors. These analyses indicate that C. niloticus exhibits populational variation that exceeds almost every other species of Crocodylus, with differences between geographic regions statistically disctinct. These results support the presence of a cryptic species complex. Additionally, an osteological description of Crocodylus niloticus is provided.
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Bateman, Joanna Rosa. "Species Delimitation Predictions Using Mitochondrial and Nuclear DNA Sequences from the Heteromys pictus-spectabilis Species Complex." BYU ScholarsArchive, 2018. https://scholarsarchive.byu.edu/etd/7457.
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Heteromys pictus-spectabilis is a species complex within the subfamily Heteromyinae (Family: Heteromyidae) that is distributed along the western and southern Mexican coast and surrounding environments. Currently, the species complex is accepted as being 2 separate species (H. pictus and H. spectabilis), but this also renders H. pictus paraphyletic. Therefore, the species complex requires re-evaluation in order to resolve the paraphyly. Mitochondrial DNA sequences from a previously existing ~720 specimen database compiled by Victoria Vance were used in conjunction with new nuclear DNA sequences sequenced for the purpose of this study to generate multiple phylogenetic trees via the software programs RAxML, BEAST, and MrBayes to evaluate how different haplotype networks were related to each other. Using these molecular datasets in consideration with Kimura two-parameter values, time calibrations via BEAST, and the relative geographic locations of the haplotype networks, the results strongly indicate this species complex is composed of multiple cryptic species and potentially multiple genera. This was a preliminary exploration into this species complex however, and future research will be required to verify these findings.
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Davidson-Watts, Ian. "Roost selection, foraging behaviour and habitat use by two cryptic species of pipistrelle bat." Thesis, Open University, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.437798.
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Kånneby, Tobias. "Gastrotricha of Sweden - Biodiversity and Phylogeny." Doctoral thesis, Enheten för zoologi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:nrm:diva-351.
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Gastrotricha are small aquatic invertebrates with approximately 770 known species. The group has a cosmopolitan distribution and is currently classified into two orders, Chaetonotida and Macrodasyida. The gastrotrich fauna of Sweden is poorly known: a couple of years ago only 29 species had been reported. In Paper I, III, and IV, 5 freshwater species new to science are described. In total 56 species have been recorded for the first time in Sweden during the course of this thesis. Common species with a cosmopolitan distribution, e. g. Chaetonotus hystrix and Lepidodermella squamata, as well as rarer species, e. g. Haltidytes crassus, Ichthydium diacanthum and Stylochaeta scirtetica, are reported. In Paper II molecular data is used to infer phylogenetic relationships within the morphologically very diverse marine family Thaumastodermatidae (Macrodasyida). Results give high support for monophyly of Thaumastodermatidae and also the subfamilies Diplodasyinae and Thaumastodermatinae. In Paper III the hypothesis of cryptic speciation is tested in widely distributed freshwater gastrotrichs. Heterolepidoderma ocellatum f. sphagnophilum is raised to species under the name H. acidophilum n. sp. The results indicate that L. squamata may be a complex of at least two species. In Paper III and V the phylogeny of Chaetonotidae (Chaetonotida), the largest family within Gastrotricha, is inferred. The group suffers from a troubled taxonomy and is hypothesized to be nonmonophyletic. Results show that members of Dasydytidae are nested within the group. Since only 3 of 17 sampled genera are monophyletic, it is hypothesized that the cuticular structures used in current classification do not reflect phylogenetic relationships. The phylogenetic hypothesis generated in Paper V indicates a marine origin of the predominantly limnic Chaetonotidae with a subsequent secondary invasion to marine environments of some taxa.Gastrotricha of Sweden - Biodiversity and Phylogeny
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Wong, Evan S. "DNA-based Species Delimitation of the Agriculturally Important Genus, Ravinia (Diptera: Sarcophagidae)." University of Cincinnati / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1439561953.
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KIssane, Kelly C. "Geographic variation and cryptic species evidence from natural populations of the fishing spider Dolomedes triton /." abstract and full text PDF (free order & download UNR users only), 2007. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3275834.
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Kunaka, Charlene. "Systematics and conservation of a widespread velvet worm species Opisthopatus cinctipes : evidence for cryptic speciation." Thesis, Stellenbosch : Stellenbsoch University, 2010. http://hdl.handle.net/10019.1/4844.
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Thesis (MSc)--Stellenbosch University, 2010.ENGLISH ABSTRACT: Opisthopatus cinctipes is a velvet worm endemic to South Africa and is widely distributed in isolated Afromontane and coastal forest patches throughout the Eastern Cape, KwaZulu-Natal and Mpumalanga. The species, like most velvet worms is characterized by low vagility, microhabitat specialization and is hypothesized to harbor significant cryptic diversity. We used partial sequence data derived from three partial mitochondrial (mtDNA) gene loci (COI, 12S rRNA and 16S rRNA) and a partial nuclear gene fragment (18S rRNA), as well as gross morphological character analysis and scanning electron microscopy (SEM) to determine evolutionary relationships amongst a total of 120 specimens of O. cinctipes from 33 localities. Phylogenetic relationships were investigated using Bayesian inferences, Maximum Parsimony and Maximum Likelihood analysis. Phylogenetic analysis of mtDNA and nDNA data revealed the presence of multiple cryptic lineages nested within Opisthopatus cinctipes with at least nine distinct well supported clades (> 70% / > 0.95 pP), suggesting that the taxon comprises a “species complex”. Afrotemperate forest specimens were genealogically highly distinct from each other whilst Indian Ocean Coastal Belt forest (at least in KwaZulu-Natal) specimens were more closely related and formed a well supported clade. An analyses of molecular variance indicated that (ΦST) 89.31% of the genetic variation occurred amongst localities. Highly significant FST values were generally observed across sampled localities (FST = 0.89, p < 0.001). Tajima’s D value was 0.83 over all sampled localities, implying a decrease in population size and/or balancing selection. Uncorrected pairwise sequence divergence values between O. cinctipes localities for the COI locus were high and ranged from 3.20% to 19.50%. No haplotypes were shared between localities. There is considerable evidence showing that past geological events may have shaped the deep genetic divergences observed between sampling localities suggesting the absence of gene flow. Genetic divergences within the South African O. cinctipes species complex are shown to have occurred from the onset of the Cenozoic era. The genetic variation observed within clades was not accompanied by morphological differences suggesting that the use of morphological characters has grossly underestimated species diversity within South African Opisthopatus. A robust taxonomic documentation of the species diversity within the O. cinctipes species complex is critical for the implementation of conservation management plans for this species complex. We recommend that highly sedentary taxa with limited dispersal abilities and specific habitat requirements which may be found in sympatry with velvet worms be prioritized for taxonomic revision as they may also harbor cryptic lineages.
AFRIKAANSE OPSOMMING: Geen Afrikaanse opsomming beskikbaar.
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Eto, Koshiro. "Systematic studies of two Japanese brown frogs." Kyoto University, 2014. http://hdl.handle.net/2433/188796.
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Kyoto University (京都大学)0048
新制・課程博士
博士(人間・環境学)
甲第18358号
人博第671号
新制||人||161(附属図書館)
25||人博||671(吉田南総合図書館)
31216
京都大学大学院人間・環境学研究科相関環境学専攻
(主査)教授 松井 正文, 教授 加藤 眞, 教授 市岡 孝朗
学位規則第4条第1項該当
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Al-Saadi, Amaal Ghazi Yasser. "Ecological divergence of cryptic species of the atyid freshwater shrimps: Caridina indistincta and Paratya australiensis species complexes at different spatial scales in South-East Queensland, Australia." Thesis, Griffith University, 2020. http://hdl.handle.net/10072/391077.
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Freshwater ecosystems represent hotspots for the world’s total diversity and human well-being. However, they are also subjected to threats across the globe as a result of localised human activities, broad scale catchment clearance, climate change and invasive species. The increased degradation of freshwater habitats and their ecological functions as a consequence of these threats, at local and global scales, has led to significant freshwater problems for human existence and the world’s biodiversity. There is growing evidence that the loss of biodiversity is one of the most complex environmental issues facing the world; however, the importance of understanding species distribution patterns and the ecological differentiation among species that are reflected as species-specific responses or tolerances to environmental drivers is less well understood. In particular, when a morphological approach is used as a taxonomic tool for investigating species diversity and species level responses to environmental drivers, the diversity of responses hidden within species complexes may not be realized, and the conclusion of generality may mask specific cryptic species responses.
In South-East Queensland, Australia, European occupation since the mid 1800’s has seen large scale clearing of native vegetation along streams and rivers in nearly all catchments. As a consequence of this land-use change catchment hydrology has been substantially altered, which, combined with the presence of dams and weirs, has resulted in a decline in water quality of streams in some catchments, which is of growing concern for conservation of species biodiversity. This study aimed to explore cryptic diversity in two species complexes of freshwater aytid shrimps common in South-East Queensland and elucidate species level responses to environmental variation that could explain their spatial distribution. This broad aim was met through three specific studies.
First, using regional scale data of cryptic species diversity and water quality, the importance of species-specific responses to environmental conditions in determining spatial distribution patterns and environmental relationships of cryptic species in the Caridina indistincta and Paratya australiensis species complexes was examined. To accomplish this aim, DNA sequences were used to identify shrimp specimens from 89 sites in 17 catchments spanning the study area. In addition, an assessment of eight morphological traits was used to test whether these cryptic species could be morphologically identified. Use of these eight traits did allow species level identification, at least in South-East Queensland. However, caution is suggested in the use of these morphological traits for recognising species, due to the probability of morphological plasticity within a species across broad spatial scales. Ordination analysis of presence-absence data showed that the five cryptic species within the two species complexes showed spatially distinct distributions across streams in SEQ, with each cryptic species displaying different relationships with individual environmental variables. For species in the Caridina indistincta complex, C. indistincta sp. B was significantly associated with elevation, C. indistincta sp. D was significantly correlated with dissolved oxygen range, whilst, individuals of C. indistincta sp. A were negatively associated with elevation and dissolved oxygen range. This may indicate that C. indistincta sp. A tended to inhabit sites with low elevation and perhaps having a higher tolerance to a low range of dissolved oxygen. For the Paratya australiensis species complex, P. australiensis lineage 4 and 6 showed significant correlations with elevation and conductivity, respectively.
The second broad aim of the study was to explore these spatial patterns at smaller geographical scales and with greater detail about water quality to understand and quantify the fundamental environmental factors (e.g., physical chemical water parameters and concentrations of heavy metals) that are potentially shaping the current distribution patterns and abundance of cryptic species within the two species complexes. To explore this aim, sediment samples from 22 sites in 13 catchments in SEQ were analysed to determine concentrations (mg/kg dry weight) of 11 heavy metals. Additionally, a number of water quality variables were measured in situ, including: elevation, stream width, stream temperature, dissolved oxygen, conductivity, pH, total dissolved solids, and turbidity. Also, a water sample was taken from each site for laboratory analysis of: Ammonium nitrogen (NH4-N), Dissolved oxidized nitrogen (Nitrate+Nitrite) (NOX-N), Total nitrogen (TN), Total kjeldahl nitrogen (TKN), Total kjeldahl phosphorus (TKP), Orthophosphate-P (PO4-P). Shrimps were collected from each site and identified to species using both morphology and DNA sequencing. The morphological identification of each adult individual (except juveniles which were genetically analysed) was used as a measure of absolute abundance and the genetic ‘checking’ of a set number of individuals in each sample was used to compute relative abundance. Redundancy analysis (RDA) showed that the spatial distribution and absolute and relative abundance of C. indistincta sp. D and sp. B were significantly positively influenced by elevation, while the relative abundance of P. australiensis Lin.6 was significantly positively affected by the concentration of manganese (Mn). Stream Total nitrogen (TN) was significantly positive driver of the spatial distribution and relative abundance of C. indistincta sp. A, while Orthophosphate-P (PO4-P) was significantly positive driver for the absolute and relative abundance of this species. Further analysis, this study confirms that P. australiensis Lin.6 was more tolerant of heavy metal concentrations compared with other cryptic species, as its distribution and absolute and relative abundance were significantly positively correlated with the concentrations of manganese, iron and cobalt. In contrast, C. indistincta sp. A was more sensitive to these metals than other study species. These results demonstrated that cryptic species of freshwater atyid shrimps of the C. indistincta and P. australiensis species complexes were different in their environmental requirements. As well, the cryptic species of both complexes were identified to have different associations with heavy metal concentrations, indicating that these species were different in their tolerance to toxicants.
Finally, the third aim of the study was to further examine the differences in sensitivity to heavy metals (Copper and Zinc) among cryptic species of the two study complexes experimentally in the laboratory. Two cryptic species of each complex were used as study species, C. indistincta sp. A and sp. D and P. australiensis Lin.4 and Lin.6. The field studies showed differences among these species in their correlations with metal concentrations, and therefore they were seen as good candidate species for testing differences in the sensitivity to metal toxicants. Each cryptic species was exposed to six concentrations of each metal Cu or Zn using an acute (96-h) toxicity test. The results from this study were generally showed contrasting correlation between species and heavy metals; P. australiensis Lin.6 was the most tolerant species to both study metals, while C. indistincta sp. A was more sensitive to copper, and C. indistincta sp. D was more sensitive to Zn compared with the other tested species. Furthermore, the exposure of individuals of each species to the heavy metals caused changes in both their behaviour and their colour during exposure time.
Overall, this study has shown cryptic species within broad species complexes can vary in their spatial distribution and their tolerance and response to water quality parameters. This highlights the advantage of using analyses of biotic and abiotic variables for ecological management and biodiversity conservation and the need to understand true species diversity when looking at species level responses to environmental degradation.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Environment and Sc
Science, Environment, Engineering and Technology
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Delaney, Paul L. IV. "Testing for Cryptic Diversity and Inference of Population Structure in the Cosmopolitan Hoplonemertean Emplectonema gracile (Nemertea)." VCU Scholars Compass, 2019. https://scholarscompass.vcu.edu/etd/6108.
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Emplectonema gracile (Johnston 1837) is a hoplonemertean of marine intertidal hard-bottom communities and is distributed throughout the Northern Hemisphere. Although possessing a planktonic larval stage in its life history, the range of such cosmopolitan marine invertebrate species is often explained by cryptic speciation and anthropogenic transport. The purpose of this study is to test for possible cryptic species using mtDNA markers (COI and 16S rDNA) and to investigate population structure in E. gracile over a portion of its geographic range using mtDNA markers and ddRADseq nuclear SNP data. The results of both phylogenetic- and tree-based species delimitation revealed that E. gracileis a morphotype containing cryptic species. Three North Atlantic and one Pacific coast population are inferred as one species (E. gracile sensu stricto) and two Pacific coast populations (Akkeshi, Japan and Charleston, Oregon) are inferred as another species (Emplectonemasp 1), strongly confirming an earlier study and extending the range of the latter species to the Pacific coast of Japan. Anthropogenic transport is suggested as the likely mode of transport for E. gracile.Both Fst, PCA and haplotype network analyses suggest a lack of differentiation between E. gracile populations separated by large geographic distances.In contrast corresponding analyses forEmplectonemasp. 1 indicate differentiation between the two populations sampled. Further research will be necessary to reveal if rare anthropogenic transport or natural dispersal (larval transport, rafting) between geographically adjacent yet to be delimitedE. gracile morphotype populations is responsible for its seemingly disjunct distribution.
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Oldham, Christian Robert. "INVESTIGATIONS IN CRYPTIC SPECIES: CONSIDERATIONS AND APPLICATIONS FOR ESTIMATING DETECTION, OCCUPANCY, AND ABUNDANCE OF SEMI-AQUATIC SNAKES." UKnowledge, 2016. http://uknowledge.uky.edu/forestry_etds/28.
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Snake species are notoriously difficult to study in the field due to their cryptic natural-histories and secretive behaviors. Difficulties associated with detection present challenges estimating parameters including occupancy and abundance, as well as responses to habitat degradation. Our objectives were to use Passive Integrated Transponder (PIT) telemetry to enhance detection of Queensnakes (Regina septemvittata) as compared to traditional capture-mark-recapture (CMR) survey techniques and to examine occupancy and abundance of Queensnakes and Northern Watersnakes (Nerodia sipedon) in streams of differing levels of anthropogenic impact within Central Kentucky. During 2013, we captured Queensnakes and implanted them with PIT tags. We detected significantly more tagged snakes using PIT telemetry than visual surveys. We did not observe significant differences in numbers of snakes detected using PIT telemetry at different times of day. We observed relatively high site fidelity of individuals. During 2014, we conducted point-count surveys of Northern Watersnakes and Queensnakes in streams characterized as highly degraded and lightly impaired. We estimated occupancy and conditional abundance among site types. We did not observe significant differences in occupancy or abundance between historically highly-impacted sites and less-impacted sites. We were able to determine significance of some environmental variables influencing detection of snakes.
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Tri, Baskoro T. S. "Cryptic species within Anopheles barbirostris Van der Wulp, 1884 : inferred from nuclear and mitochondrial gene sequence variation." Thesis, University of Liverpool, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.250419.
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Wollschlager, Jennifer M. "Nematocysts of the Invasive Species Cordylophora caspia." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1299609133.
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Metegnier, Gabriel. "From gene expression to genetic adaptation : insights into the spatio-temporal dynamics of Alexandrium minutum cryptic species complex." Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS200/document.
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Les populations naturelles sont confrontées à des changements environnementaux. Pour y faire face, différentes réponses ont été sélectionnées au cours de l'évolution. Parmi elles se trouvent la plasticité phénotypique et l'adaptation génétique. Etudier les liens existants entre elles est une manière de comprendre les dynamiques des populations et de prévoir leurs réponses à un environnement changeant. Dans la présente étude, je me suis attaché à étudier ces liens à plusieurs échelles (intra- et interspécifique), chez le complexe d'espèces cryptiques de la micro-algue Alexandrium minutum, et ce à la fois in vitro et in situ. En ce qui concerne la plasticité phénotypique, ces deux espèces proches montrent de profondes différences, soulignant les liens entre divergence génétique et écologique. Au niveau intraspécifique, il apparaît que face à des variations de facteurs abiotiques, les populations ajustent les niveaux d'expression de certains gènes (notamment impliqués dans des fonctions de motilité et d'interactions intercellulaires dans des environnements froids à faible salinité). D'autre part, les populations montrent de la différentiation génétique à la fois à faible échelle spatiale, au cours du temps, et lorsque la communauté change. Pour conclure, il existe une interaction directe entre divergence génétique et changements d'expression de gènes. En plus de poser de nombreuses questions quant aux capacités de réponse des populations, ces résultats soulignent comment plasticité phénotypique et changements génétique sont liés et interagissent. Ils offrent une perspective nouvelle sur les mécanismes qui sous-tendent les réponses des populations à leur environnementNatural populations face environmental changes. In this context, different responses were evolutionnary selected. Among them are phenotypic plasticity and genetic adaptation. Studying the links between these two types of response is a way to understand population dynamics and to predict how they may respond to a changing environment. In the present Ph.D thesis, I focused on studying these links at several scales (intra- and interspecific), in the cryptic species complex of the microalga Alexandrium minutum, both in vitro and in situ. With respect to phenotypic plasticity, these two closely related species show profound differences, highlighting the links between genetic and ecological divergence. At the intraspecific level, it appears that, when facing abiotic factors variations, populations adjust the expression levels of certain genes (notably involved in motility related functions and intercellular interactions under low-salinity and cold environments). On the other hand, populations show genetic differentiation at both small spatial scale, over time, and when the community changes. To conclude, there is a direct interaction between genetic divergence and changes in gene expression. In addition to asking many questions about the response capabilities of populations, these results highlight how phenotypic plasticity and genetic changes are linked and interact. They offer new perspectives on the mechanisms underlying population responses to their environment
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Oliveira, Luciana Bonome Zeminian de. "Genotipagem do Paracoccidioides brasiliensis de diferentes amostras de pacientes atendidos no Hospital das Clínicas da Faculdade de Medicina de Botucatu." Botucatu, 2018. http://hdl.handle.net/11449/153677.
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Orientador: Luciane Alarcão Dias-MelicioResumo: A paracoccidioidomicose é uma micose granulomatosa sistêmica, prevalente na América Latina, e que até recentemente acreditava-se ser causada apenas por uma espécie de fungo, o Paracoccidioides brasiliensis (P. brasiliensis). No entanto, em 2006, pesquisadores descreveram três espécies crípticas: S1, PS2, PS3 e, posteriormente o PS4. Em 2009, o Paracoccidioides lutzii (Pb01-like) foi descrito, e ano passado, em 2017, uma nova nomenclatura foi proposta para esses agentes etiológicos distintos: P. brasiliensis (S1), P. Americana (PS2), P. restrepiensis (PS3) e P. venezuelensis (PS4). Todos esses agentes são fungos termodimórficos que crescem como levedura in vivo, no hospedeiro, em tecidos ou em culturas in vitro a 37°C e como micélio à temperatura ambiente (4 a 28°C). As espécies não são uniformemente distribuídas pela América Latina, sendo algumas mais proeminentes em algumas regiões do que em outras. O Hospital das Clínicas da Faculdade de Medicina de Botucatu é polo de estudo da paracoccidioidomicose e situado na região centro-oeste do estado de São Paulo, considerada uma área endêmica. Devido à existência de espécies crípticas de Paracoccidioides, análises mais detalhadas nas amostras de pacientes tornaram-se necessárias para uma melhor compreensão de distribuição e ocorrência das espécies recentemente descritas nessa região, favorecendo uma possível correlação entre os grupos genéticos e características micológicas e clínicas. Os objetivos foram obtenção de dados epidemiol... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Paracoccidioidomycosis is a chronic granulomatous mycosis prevalent in Latin America, that until recently it was believed to be caused only by Paracoccidioides brasiliensis (P. brasiliensis). However, in 2006, researchers described cryptic species: S1, PS2, PS3, and PS4. In 2009, Paracoccidioides lutzii (Pb01-like) was described, and now, a new nomenclature was proposed for the other different agents: P. brasiliensis (S1), P. Americana (PS2), P. restrepiensis (PS3), and P. venezuelensis (PS4). All these agents are thermodimorphic fungi that develop as yeast in vivo, in host tissues or in vitro cultures at 37°C in culture media. It also grows as mycelium at room temperature ranging from 4 to 28°C. These species are not uniformly distributed throughout Latin America, some are more prominent in some regions than in others. The Hospital of Medical School of Botucatu - UNESP, which is a paracoccidioidomycosis study pole, is in São Paulo state midwest region, that is classified as an endemic area. Due to the existence of cryptic species of Paracoccidioides, further analyses of patient samples are needed for a better understanding the distribution and occurrence of these recently described species in Botucatu region, that could favor a possible correlation between genetic groups and mycological and clinical characteristics. Given the importance of this disease to the region, the aims of this study were to perform a retrospective epidemiological, geographical and clinical study gathe... (Complete abstract click electronic access below)
Doutor
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Berge, Lene. "Resource partitioning between the cryptic species Brandt's bat (Myotis brandtii) and the whiskered bat (M. mystacinus)in the UK." Thesis, University of Bristol, 2007. http://hdl.handle.net/1983/7bdc4dc7-9a0d-4a63-80e0-ff1d45ad0f76.
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Akin, Cigdem. "Detection Of Species Boundaries In The Rana Ridibunda Complex Of Southwestern Turkey Using Mitochondrial Nd3 Marker." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/3/12608156/index.pdf.
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Water frogs are one of the most interesting vertebrate groups, showing great diversity and complexity in their reproductive modes, ecology and evolutionary relationships, and with many cryptic species due to high morphological similarity. For many decades, a single species, Rana ridibunda, has been suggested to exist in Turkey. However, the application of new morphometric, molecular and bioacoustic techniques has recently revealed the occurrence of several distinct water frog taxa in Turkey.
In this study, 340 bp long mtDNA ND3 region in 195 specimens was sequenced and subjected to phylogenetic analyses to detect geographical structure and species boundaries. Neighbor joining tree, minimum spanning network, SAMOVA and AMOVA were used to understand relationship within and among clades. Population demography was studied through mismatch distribution and neutrality tests.
Results indicated that populations in southwestern Turkey show high diversity and strong geographic structuring. In Turkey there are four major maternal lineages, each probably representing a species: Thrace lineage represents Rana ridibunda Pallas 1771 in European TurkeyCeyhan lineage indicates an unnamed taxon in Cilicia plain
South-central lineage occurs at the Lake District, Antalya, Konya and Karaman provinces and represents Rana caralitana Arikan, 1988
Anatoliaca lineage (occuring in Asiatic Turkey except for central southern Turkey, Rhodes &
Karpathos, northeastern Syria, and probably also Iraq and Transcaucasia) is designated either as Rana cerigensis Beerli, Hotz, Tunner, Heppich, and Uzzell 1994 or as a new subspecies of R. caralitana, based on the degree of reproductive isolation present between the last two lineages.
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Perrigo, Allison L. "Diversity Underfoot : Systematics and Biogeography of the Dictyostelid Social Amoebae." Doctoral thesis, Uppsala universitet, Systematisk biologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-210074.
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Dictyostelids (Amoebozoa) are a group of social amoebae consisting of approximately 150 species, which are found in terrestrial habitats worldwide. They are divided into eight major clades based on molecular phylogeny, and within these clades are many species complexes. Some species are seemingly cosmopolitan in distribution, while others are geographically restricted. In this thesis dictyostelids were recovered from high latitude habitats (soils in Sweden and Iceland) as well as from the soles of shoes. Morphological characters and DNA sequence analyses were used to identify isolates that were recovered and delimit new species, as well as to investigate the monophyly of Dictyostelium aureostipes. Nine species were reported from Northern Sweden and four from Iceland. Among the isolates recorded in Sweden were two new species, described as D. barbibulus and Polysphondylium fuscans. P. fuscans was among the four species recovered from footwear, contributing evidence for anthropogenic transport of dictyostelids. Ecological patterns were assessed using linear regression and generalized linear models. The ecological analyses of dictyostelids recovered from Iceland indicate that these organisms are most frequently found in soils of near-neutral pH, but also exhibit a species richness peak in moderately acidic soils. These analyses indicate that in Iceland dictyostelid species richness decreases with altitude, and in the northern hemisphere the species richness increases with decreasing latitude. A three-region analysis of the D. aureostipes species complex indicated that this species is in fact made up of at least five phylogenetically distinct clades, and in light of this the group is in need of taxonomic revision. These results indicate that the dictyostelid species richness is higher than previously known, especially in high-latitude regions, and that even seemingly well-defined species may harbour cryptic diversity. Presently, species ranges may be expanding via anthropogenic dispersal but despite this, the dictyostelids are found to exhibit biogeographic trends well known from macroorganisms, such as a latitudinal gradient of species richness.
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Klooster, Matthew Roger. "Reproductive ecology and population genetics of myco-heterotrophic plant species in the Monotropoideae (Ericaceae)." University of Cincinnati / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1211900219.
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Araujo, Natália de Souza. "Análise de espécies crípticas do complexo Anastrepha fraterculus (Díptera: Tephritidae) no Brasil através de sequências do gene mitocondrial cytochrome oxidase I." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/41/41131/tde-18122012-225903/.
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A família Tephritidae congrega várias espécies de moscas-das-frutas que utilizam frutos como substrato alimentar no estágio larval, adquirindo o status de inseto-praga quando esses frutos são de valor comercial. O gênero Anastrepha é endêmico do Continente Americano e compreende cerca de 212 espécies descritas, das quais 109 ocorrem no Brasil. A espécie nominal Anastrepha fraterculus representa um complexo de espécies crípticas e se encontra distribuída pela Região Neotropical e sul dos Estados Unidos. No Brasil, através do estudo de diversas características biológicas e do marcador molecular ITS-1 (espaçador ribossômico nuclear), identificou-se a existência de três espécies crípticas no complexo fraterculus, a Anastrepha sp.1 affinis fraterculus, A. sp.2 aff. fraterculus e A. sp.3 aff. fraterculus. Marcadores gênicos presentes no DNA mitocondrial, como o gene cytochrome oxidase I (COI), são ferramentas amplamente utilizadas em análises filogenéticas, pois esta molécula apresenta características distintas do DNA nuclear, como o fato de possuir herança predominantemente materna, apresentar ausência ou baixíssima taxa de recombinação na maioria dos táxons, além de altas taxas mutacionais. Estas características possibilitam a obtenção de dados importantes na interpretação das relações entre as espécies. Amostras do complexo fraterculus (A. sp.1, A. sp.2, A. sp.3) de 14 localidades (média de 5 indivíduos / localidade) no sudeste do Brasil, uma amostra de A sp.4 do Equador e dois grupos externos (A. grandis e A. striata) foram utilizados. Fragmentos de 1139bp do gene COI foram amplificados e sequenciados, 45 haplótipos foram identificados: 30 em A. sp.1, 5 em A. sp.2 e 17 em A. sp.3. A distância média entre as espécies foi de 0,021 e o Fst médio foi 0,347 indicando estruturação populacional muito alta e pequena distância entre os haplótipos, que não apresentaram diferenças fixadas entre as espécies. Os testes de desvio de neutralidade apresentaram valores significativamente negativos. Os testes de seleção evidenciaram a atuação de seleção purificadora com baixos valores de Ka/Ks e significância no Z-teste de seleção. A análise filogenética mostrou fortes evidências de introgressão e não separou as diferentes entidades em clados distintos. Houve a formação de dois ramos principais, um constituído quase que exclusivamente por amostras de A. sp.1, e apenas duas amostras de A. sp.3, e outro que reuniu todas as espécies do complexo. Os dois principais grupos de haplótipos também foram visualizados na rede de haplótipos que mostrou indícios de expansão populacional. Quando somado ao estudo sequências depositadas em bancos de dados por outros autores, a espécie nominal A. fraterculus apresentou em sua distribuição 5 grupos de haplótipos mitocondriais. Dois deles ocorrem no Brasil, um com amostras do México e Costa Rica, um na Guatemala e Venezuela (baixa latitude) e um com indivíduos da Colômbia e Venezuela (alta latitude), sendo que os grupos Brasileiros também reuniram amostras da Argentina e do Equador. Assim, as sequências de COI não permitem a caracterização das entidades do complexo fraterculus apesar de indicar a estruturação populacional e a hipótese mais provável é a de que tenha havido introgressão da molécula mitocondrial entre as espécies do complexo com posterior expansãoThe Tephritidae family comprises fruit flies species whose larvae feed and develop in fruits, many of which are commercial varieties and thus the species assume economic significance. Anastrepha genus is distributed throughout the Neotropical region and Southern United States. Analyses of biological characteristics and of the internal transcribed spacer (ITS-1) of the nuclear ribosomal DNA allowed the characterization of three cryptic species of the fraterculus complex in Brazil: Anastrepha sp.1 affinis fraterculus, Anastrepha sp.2 aff. fraterculus and Anastrepha sp.3 aff. fraterculus. Mitochondrial markers as gene cytochrome oxidase I (COI) are largely used in phylogenetic analyses because they have maternal inheritance, none or low recombination and high mutation rates compared to the nuclear DNA. Hence, analyses of the complex based in this marker will offer a divergent perspective from nuclear DNA for inferences on the evolutive relationships between different species. Samples from the fraterculus complex (A. sp.1, A. sp.2, A. sp.3) from 15 localities (average of 5 individuals/ locality) in southeastern Brazil, one sample of A. sp.4 from Ecuador and two outgroups (A. grandis and A. striata) were employed and COI sequences of 1139bp were amplified and analyzed. We identified 45 haplotypes: 30 in A. sp.1, 5 in A.sp.2 and 17 in A. sp.3. The mean distance between the haplotypes was 0.021 and mean Fst 0.347, indicating high population structure and low mitochondrial distance. The neutrality tests had significantly neutral values. The selection tests revealed the action of purifying selection with low values of Ka/Ks and significance in the Z-test selection. Phylogenetic analysis showed strong evidences of introgression and did not separate the various entities in distinct clades grouping the three species in a single branch; there was also the formation of another main branch formed almost exclusively by strains of A. sp.1 and only two samples of A. sp.3. The two main groups of haplotypes were also seen in the haplotype network that showed evidence of population expansion. The analysis of the philogenetic tree based on mitochondrial COI showed strong evidence for introgression. No fixed differences between species were found though mtDNA marker shows a lot of polymorphism. When added sequences deposited in databases by other authors the nominal species A. fraterculus presented in its distribution five groups of mitochondrial haplotypes, two of them in Brazil, one with samples from Mexico and Costa Rica, one in Guatemala and Venezuela and one with individuals from Colombia. The Brazilian groups also collected samples from Argentina and Ecuador. Therefore, the COI sequences do not allow the characterization of the entities of the fraterculus complex, although structure among the species is shown. The most likely hypothesis is that introgression has happened in the mitochondrial molecule among the species with further expansion
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Islam, R. "Genetic structure and life history variation in a cryptic fish species complex, Australian smelt (Retropinna semoni) across south-east Queensland, Australia." Thesis, Griffith University, 2018. http://hdl.handle.net/10072/379294.
Full textAbstract:
Generally freshwater fish exhibit higher levels of genetic structuring between spatially distinct populations than marine species due to the presence of natural and artificial barriers to dispersal in freshwater ecosystems. In addition, freshwater species are not able to move between populations that are separated by either terrestrial or marine habitat. Diadromy constrains the development of genetic structuring, even among geographically isolated populations due to potential connectivity via movement through the sea. As a result, higher levels of gene flow and lower population structuring tend to be observed in diadromous fishes than freshwater species.
The Australian smelt (Retropinna semoni) is a native fish species complex widely distributed across coastal and inland drainages of south-eastern Australia. Recently, a complex of five or more cryptic species of Australian smelt has been recognized throughout their geographic range based on genetic studies. Variation in life history strategies has been observed in many cryptic fish species and multiple life history patterns were also found in southern smelt lineages (Retropinna sp.) where mainland Australian populations contain diadromous and wholly freshwater individuals and Tasmanian populations contain estuarine individuals. Despite the populations of southern smelt containing diadromous individuals, strong genetic structuring and low levels of connectivity were reported in at least some populations, which were suggested to result from apparently diadromous individuals being retained in the estuaries. It is possible that the different cryptic species may differ in life history. In the present study, I examine the genetic structure and life history variation of the South-east Queensland (SEQ) lineage of Australian smelt which was further subdivided into northern and southern lineages (SEQ-N, SEQ-S).
I used both molecular and ecological approaches to understand the pattern of genetic structure and life history variation in this species to compare with other members of the species complex. Prior to this task, twenty one polymorphic microsatellite primers were developed (Chapter 2), which were then used for species delimitation and population structure analysis.
In chapter 3, I used one mitochondrial gene (cyt b) and ten microsatellite loci to investigate patterns of genetic structuring in Australian smelt (R. semoni) and describe the genetic differences between these two cryptic lineages (SEQ-N and SEQ-S). These two lineages formed monophyletic clades in the mtDNA gene tree and among river phylogeographic structure was also evident within each clade. There was clear genetic divergence between the two lineages, suggesting that they have been separated historically by a hard barrier. Strong genetic structuring was observed from microsatellite analysis in both lineages (SEQ-S FST = 0.13; SEQ-N FST = 0.23) suggesting limited dispersal among rivers. Slightly lower levels of genetic structuring were observed in the SEQ-S lineage than the SEQ-N lineage. This might be the result of different microhabitat preferences between these two cryptic lineages (SEQ-N and SEQ-S), for example intolerance to water quality parameters. Another plausible explanation is that SEQ-S catchments may have been connected more recently and /or more often than those in the SEQ-N group during flood events. Contemporary movement of individuals only occurred between nearby sites within a river, but not between rivers, suggesting that if local extinctions occur in one or more of these rivers, then recolonization from elsewhere is unlikely to occur rapidly. Similarly, extinctions within a site are only likely to be recolonised from nearby sites in the same river.
In chapter 4, I used otolith micro-chemistry analysis to examine the life history patterns of smelt at the northern extent of their range and to identify any differences in migratory behaviour of the two lineages (SEQ-N and SEQ-S) in this region. Based on otolith core-to-edge transects of Sr:Ca and Ba:Ca, there was no evidence of marine residence for either lineage suggesting that both are non-diadromous. This contrasts with the two southern smelt species, in which both exhibit evidence of diadromous movement of individuals within some populations.
Significant differences in multi-elemental otolith chemistry signatures were observed among rivers and between paired sites within some rivers, suggesting no exchange of individuals among catchments and limited dispersal of individuals over large spatial scales within a river. This is almost certainly the result of the marine habitat conditions along the coastal drainages which isolate rivers and restrict movement of fish between them, combined with some limited dispersal within a river. In addition, movement of fish may also be precluded due to anthropogenic migration barriers within river catchments.
This study has presented a holistic view of population structure using ecological and genetic markers and revealed that R. semoni is highly structured across south-east Queensland from the Mary River to Currumbin Creek. Genetic analysis delivers the general framework for applying ecological methods and substantial information regarding exchange between populations. Sensitive ecological methods such as otolith chemistry provide resolution of the fine-scale spatial separation within and between sample collection locations because movements within an individual lifetime can be inferred. The results of the present study emphasise the advantages of using complementary methods to evaluate the connectivity of fish populations. The combination of otolith chemistry and molecular markers provided insights into the role of migration in structuring smelt populations over a range of temporal and spatial scales. Overall, the current study furnished new insights into the population genetic structure and life history patterns of Australian smelt, which has significant implications for the sustainable management and conservation of this ecologically variable species along coastal drainages in south-east Queensland.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Environment and Sc
Science, Environment, Engineering and Technology
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Cambridge, Tucker. "Species Distribution and Conservation Genetics of the Upland and Midland Chorus Frogs (Pseudacris) in Kentucky." TopSCHOLAR®, 2018. https://digitalcommons.wku.edu/theses/3063.
Full textAbstract:
The upland (Pseudacris feriarum) and midland (P. triseriata) chorus frogs are closely related cryptic species that are best distinguished genetically. The distribution of these species within the Commonwealth of Kentucky has previously been defined by only a handful of genetic samples, making delineation of range limits for each species difficult. Accurate understanding of species distributions, and the genetic structure within them, are vitally important for conservation management of amphibian species. In this study, I have collected genetic samples from across the putative ranges of P. triseriata and P. feriarum in Kentucky and used next-generation sequencing technology to generate more fine-scale estimates of species ranges. The genetic data generated in this study support the delineation of two species in Kentucky, and the species assignments of all individuals and populations are in general concordance with the previously hypothesized species distributions. However, I have identified two previously unrecognized contact zones for these species and revealed areas of hybridization. By delineating species distributions and identifying potentially important regions of genetic admixture, this study will be informative to future conservation management and conservation genetic research of chorus frogs in Kentucky.
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Van, Leeuwen Travis Edward. "Variation in metabolic rate between individuals and species : cryptic physiological tradeoffs underlying habitat partitioning and life history strategies of juvenile salmonids." Thesis, University of British Columbia, 2010. http://hdl.handle.net/2429/28689.
Full textAbstract:
Physiological traits such as standard metabolic rate have been shown to vary up to half an order of magnitude between individuals and species and influence key life history tradeoffs in juvenile salmonids (e.g. smolt timing).
The purpose of my thesis research was to examine the relationship between food consumption, dominance and disproportionate feeding on physiological traits and adaptive strategies of juvenile salmonids.
Results show that SMR is positively correlated with food consumption and growth in juvenile coho salmon which showed a reduction in SMR under low food and an elevation in SMR under high food (Chapter 2).
Comparisons between hatchery and wild juvenile steelhead and coho salmon revealed no difference in Stnadard metabolic rate between wild coho and wild steelhead but a significant difference in the hatchery fish, with hatchery steelhead being higher. In both wild and hatchery populations I found a marked difference in maximal metabolic rate between steelhead and coho, leading to a greater aerobic scope and swim performance in wild steelhead but no difference in the hatchery fish. This result is consistent with a steelhead energy maximizing strategy, habitat partitioning and trade-offs between elevated SMR at higher growth and decreased swim performance. Interestingly, wild steelhead with higher maximum growth, swim performance, and maximum food consumption do not appear to tradeoff increased growth against lower swim performance, as commonly observed for high growth strains. Instead steelhead appear to be trading off higher growth for lower food consumption efficiency; highlighting potential differences in food consumption and digestion strategies as cryptic adaptations that have received little attention.
In experiments conducted in semi-natural stream channels, I found that dominant coho salmon were able to achieve higher absolute growth rates compared to smaller subordinates, at high food ration but suffered significantly lower absolute growth at low food ration as larger dominant fish approached the capacity of their habitat (Chapter 4).
Overall I demonstrated that the relationship between physiological traits, life history strategy and dominance rank depended on per capita food consumption rates, habitat characteristics (pools vs riffles) and the absolute size of individuals in a dominance hierarchy.
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Roderique, Bonnie A. "IMPROVING THE CONSERVATION OF A CRYPTIC ENDANGERED FRESHWATER MUSSEL (PARVASPINA COLLINA) THROUGH THE USE OF ENVIRONMENTAL DNA AND SPECIES DISTRIBUTION MODELING." VCU Scholars Compass, 2018. https://scholarscompass.vcu.edu/etd/5552.
Full textAbstract:
Conservation efforts that involve habitat protection, population augmentation, and species reintroductions require knowledge of the habitat requirements, distribution, and abundance of a species—information that can be challenging to acquire, especially for rare organisms with patchy distributions. In this thesis, I develop a protocol for the use of environmental DNA (eDNA) and create a Species Distribution Model for the endangered James spinymussel, Parvaspina collina (Unionidae). The results of this work show that eDNA is a robust tool for identifying species presence but not for estimating the relative abundance of populations. This study found that P. collina’s distribution is influenced by abiotic habitat characteristics related to sedimentation and runoff rather than by the distribution of its host fishes. The predicted habitat suitability was used to identify locations of priority conservation concern and these results can be used to direct future sampling efforts, identify potential dispersal routes, and inform conservation decisions.
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Rogl, Kimberley. "A genomics perspective of species and speciation in an Atyid shrimp (Paratya australiensis)." Thesis, Queensland University of Technology, 2021. https://eprints.qut.edu.au/207248/1/Kimberley_Rogl_Thesis.pdf.
Full textAbstract:
The speciation debate in evolutionary science is long and protracted, evidenced by the multitude of concepts regarding species and speciation. Understanding the nature of species however, is of central importance in the study of biology and ecology. The purpose of this study was to investigate the genetic architecture of freshwater shrimp (Paratya australiensis) from two distinct lineages and of individuals across a known hybrid zone to gain insight into the process of speciation at the molecular level. The results of this study indicate that P. australiensis lineages sit in an advanced position along the speciation continuum, thus warranting taxonomic revision.
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Larsson, Karolina. "Taxonomy and Phylogeny of Catenulida (Platyhelminthes) with Emphasis on the Swedish Fauna." Doctoral thesis, Uppsala University, Department of Evolution, Genomics and Systematics, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-8470.
Full textAbstract:
This thesis focuses on phylogenetic and taxonomic studies of Catenulida (Platyhelminthes). Catenulida is a group of microscopic free-living worms mainly found in freshwater habitats. The Swedish catenulid fauna was previously virtually unknown. The taxonomy of Catenulida is difficult because of the paucity of good morphological characters, which makes species identification extremely difficult.
Molecular phylogenies are inferred from DNA sequences. Based on two molecular markers, 18S rDNA and 28S rDNA, the phylogenetic position of Catenulida has now been well established as the sister group to the rest of the flatworms, Rhabditophora. Within Catenulida there is a basal split between two major clades: Retronectidae + Catenulidae and Stenostomidae. The hypothesis of the marine Retronectidae as the sister group of the limnic Catenulida is rejected.
Four molecular markers, 18S rDNA, 28S rDNA, ITS-5.8S and CO1, are used as a backbone to infer phylogeny and to generate hypotheses about species delimitation in Catenulida using parsimony jackknifing and Bayesian analysis. Anokkostenostomum comes out non-monophyletic, and Suomina nested within Catenula, so two new synonymies are proposed: Stenostomum Schmidt, 1848 (Anokkostenostomum Noreña et al. 2005) and Catenula Duges, 1832 (Suomina Marcus, 1945) are proposed.
A first report on Swedish freshwater Catenulida are given. A total of 13 species are reported from Sweden. Four of them, all belonging to the taxon Stenostomum are new to science: S. gotlandense n.sp.; S. handoelense n.sp.; S. heebuktense n.sp. and S. steveoi n.sp.
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COSTA, JUNIOR Cesar Raimundo Lima. "Estruturação genética e polimorfismos fixados no gene period entre populações naturais de Lutzomyia longipalpis no Brasil." Universidade Federal de Pernambuco, 2016. https://repositorio.ufpe.br/handle/123456789/17908.
Full textAbstract:
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FACEPE
O status taxonômico de espécie tem se mostrado essencial em relação a conservação de espécies como também para estudos eco-epidemiológicos. O status taxonômico em insetos vetores tem demonstrado que muitas espécies anteriormente ditas como únicas, compreendiam, na verdade, um complexo de espécies crípticas em que seus integrantes podem ter capacidades vetoriais diferenciadas, e.g. Anopheles gambie Lutzomyia longipalpis sl, inseto vetor da Leishmania infantum (agente etiológico da leishmaniose visceral americana), possui status taxonômico ainda controverso e diversos estudos têm sido realizados à fim de esclarecer o real status deste vetor. Apesar de diversas populações apresentarem características exclusivas (e.g. feromônios, sons copulatórios, padrões de manchas abdominais e estrutura genética), a quase duas décadas apenas uma espécie do complexo foi descrita, a L. pseudolongipalpis. Foi avaliado três localidades do nordeste do Brasil, das quais duas possuem como barreira geográfica a Chapada do Araripe. Foram utilizadas metodologias robustas como Análise de Máxima Verossimilhança, Teste de atribuição e AMOVA.Este estudo utilizou um fragmento do gene period, sendo que o Teste de Atribuição, Fst e a Máxima Verossimilhança separaram agruparam os dados genéticos com as diferenças fenotípicas e pela primeira vez o AMOVA demonstrou que a maior variação genética estava na relação entre o número de manchas abdominais e a estrutura genética das populações, sendo o primeiro trabalho a evidenciar a ancestralidade do fenótipo que apresentava uma mancha abdominal (1S) em relação ao fenótipo com duas manchas (2S). O Fst encontrado evidenciou, pela primeira vez, as relações filogeográficas separando moderadamente as populações isoladas pela a chapada do Araripe.
he taxonomic status of species is essential for conservation and has also been of great importance in eco-epidemiological studies. The definition of the taxonomic status for insect vectors has demonstrated that several previously identified species are in fact comprised of a complex of cryptic species with different vectorial capacity (e.g. Anopheles gambie). For the sand fly Lutzomyia longipalpis sl, principal vector of Leishmania infantum, the etiological agent of American visceral leishmaniasis, the taxonomic status remains controversial and several studies have been conducted to clarify the actual status of this vector. Although diverse populations present unique characteristics (e.g. pheromones, copulatory sounds, patterns of abdominal spots and genetic structure), for nearly two decades only one species of the complex was described, L. pseudolongipalpis. In this study, we evaluated three sites in Northeastern Brazil where two of them have as geographical barrier the plateau of Araripe. The study used robust methods such as Maximum Likelihood analysis, assigning test and AMOVA. The present study used a fragment of the period gene (525 base pairs), and has demonstrated for the first time a relationship between the number of abdominal spots and the genetic structure of the population, being first study to show the ancestry of the phenotype showed one abdominal spot (1S) compared to the phenotype with two spots (2S). As well as the Fst found separated populations isolated by the Araripe plateau.
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Gimenes, Kethely Fernandes Brasil. "Delimitação de espécies em Cubozoa : morfologia e molecular do gênero Tamoya /." Assis, 2017. http://hdl.handle.net/11449/151448.
Full textAbstract:
Orientador: Sérgio Nascimento StamparResumo: Existe uma considerável abundância de espécies de cnidários no litoral do Brasil e uma das espécies mais intrigantes e pouco conhecidas é a Tamoya haplonema, a qual dentre suas características mais interessantes se destaca a presença de um padrão de bandas nos tentáculos, o que não é comum nos cubozoários, classe à qual pertence. Essa espécie é conhecida desde meados do século XIX, sendo uma das poucas espécies no Atlântico Sul capaz de causar acidentes graves em humanos. Em 2011 alguns registros de espécimes do mesmo gênero para o Mar do Caribe resultaram na descrição de uma nova espécie, Tamoya ohboya. Essa espécie foi delimitada, principalmente, por dados moleculares e devido à disponibilidade de poucos indivíduos a definição é dúbia em vários trechos. Já foi constatado que o cenário taxonômico do gênero Tamoya no Atlântico Ocidental não é consistente. Desta maneira, o principal objetivo deste estudo foi a comparação taxonômica do gênero Tamoya no Atlântico Sul e Mar do Caribe.Para tal, indivíduos do gênero Tamoya do Atlântico Sul foram analisados e comparados com T.ohboya, utilizando dados morfológicos/morfométricos e moleculares, incluindo o estudo da composição dos nematocistos através das medidas e análises comparativas. Os resultados morfológicos, bem como a análise do cnidoma e os resultados moleculares deixam claro que T.haplonema e T.ohboya são na realidade a mesma espécie.
Abstract: There is a considerable abundance of cnidarian species along the Brazilian coast and one of the most intriguing and little known species is the medusa Tamoya haplonema, which among its most interesting characteristics stands out the presence of a pattern of bands in the tentacles, which is not common in the Cubozoa, the class to which it belongs. This species has been known since the mid-nineteenth century, being one of the few species in the Southern Atlantic capable of causing serious stings to humans. In 2011 specimens of the same genus the Caribbean Sea resulting in the description of a new species, Tamoya ohboya. This species was delimited, mainly, by molecular data and due to the availability of few individuals the definition is dubious in several parts. It has already been verified that the taxonomic scenario of the genus Tamoya in the Western Atlantic is not consistent. Thus, the main objective of this study was the taxonomic comparison of the genus Tamoya in the South Atlantic and the Caribbean Sea. Thus individuals of the genus from the South Atlantic were analyzed and compared with T.ohboya, using morphological / morphometric and molecular data, including the study of the nematocysts composition through measurements and comparative analyzes. The morphological results as well as the analysis of the cnidome and molecular results make it clear that T.haplonema and T.ohboya are actually the same species.
Mestre
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Moffat, Chandra Elaine. "Cryptic host-associated and frequency-dependent patterns of host species selection of a candidate weed biological control agent in its native range." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/43199.
Full textAbstract:
At least nine species of European hawkweeds in the genus Pilosella Vaill. (Asteraceae) are
invasive in western North America, where they are a detriment to natural and managed lands and
have vast economic impacts. A promising candidate biological control (biocontrol) agent for
multiple species of Pilosella is the gall inducing wasp Aulacidea pilosellae Kieffer
(Hymenoptera: Cynipidae). Initial studies of this candidate agent revealed the potential for two
biotypes of the insect that differed in physiological host range, voltinism, and reproductive
mode. It was hypothesized that these differences were related to geographic separation of the
populations and it was further observed, within one subset of the distribution, that different host
species were being used at nearby sites, despite similar host species being present. The
overarching goal of this thesis was to increase the understanding of the patterns of host species
use by A. pilosellae in order to inform the biocontrol programme for invasive Pilosella
hawkweeds. The specific objectives were to (i) test the hypothesis that A. pilosellae has
definitive preferences for species of Pilosella within its ecological host range, (ii) further
quantify the ecological host range of A. pilosellae by conducting systematic surveys across a
broad geographic distribution, and (iii) test the hypothesis that differences between the purported
biotypes were due to cryptic genetic differentiation, predicted to be based primarily on
geographic location of populations and secondly on host-association. By utilizing an integrative
approach of thorough and widespread field surveys and molecular methodologies, this thesis
presents findings that substantially increase the understanding of patterns of host species use by
A. pilosellae in its native range. Specifically, (i) the hypothesis of host preferences of A.
pilosellae is rejected in favor of frequency-dependent host species selection, (ii) five species of
Pilosella invasive in North America are confirmed as hosts of A. pilosellae in its native range
and (iii) the hypothesis that cryptic genetic differentiation exists within the species A. pilosellae
was supported. However, the prediction that differentiation was based primarily on geographic
separation was rejected in favor of differentiation based on a combination of disjunct hostassociations,
infection with the bacterial endosymbiont Wolbachia, and to a lesser extent, on
geography.
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Sato, Hirotoshi. "Detection of cryptic species and elucidation of host specificity in the ectomycorrhizal genus Strobilomyces based on information of nucleotide sequences of DNA." 京都大学 (Kyoto University), 2008. http://hdl.handle.net/2433/136936.
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Hinojosa, Galisteo Joan Carles 1993. "Exploring the butterfly speciation continuum : A study on butterfly speciation in the transition to genomic techniques." Doctoral thesis, Universitat Pompeu Fabra, 2021. http://hdl.handle.net/10803/672348.
Full textAbstract:
Butterflies are among the best studied animals, but despite the research efforts carried out during
centuries, our knowledge on their diversity and on the mechanisms generating it is still incomplete.
In order to understand how butterflies diversify, the speciation continuum of six study cases was
examined using morphometrics and several genetic techniques (from sequencing specific markers
to genomics). The analysis of phenotypic and genetic variation combined with gene flow evidence
allowed to identify the states of the speciation continuum, i.e. to study the relationships between
populations. This approach was used as a framework (1) to make grounded taxonomic hypotheses
and (2) to extract clues about the mechanisms that drive speciation. As a result, we described and
proposed several cases of overlooked and oversplit taxa. We documented the existence of three
types of mechanisms producing diversification in butterflies: drift, selection and hybridisation.
Selection acted through adaptation to biotic environmental factors, which caused reproductive
character displacement, host plant shift and allochrony mediated by adaptation to host plant
flowering period. Additionally, the genetic techniques employed were evaluated and their
advantages and limitations discussedLes papallones són un dels animals més ben estudiats però, malgrat els esforços dedicats a la seva recerca, el coneixement que tenim sobre la seva diversitat i sobre els mecanismes que la generen és encara incomplet. Per tal d'entendre com les papallones diversifiquen, s'ha examinat el continu de l'especiació en sis casos mitjançant l'ús de la morfometria i de diverses tècniques genètiques (des de la seqüenciació de marcadors específics fins a la genòmica). L'anàlisi de la variació fenotípica i genètica combinada amb evidències sobre el flux genètic ha permès identificar els estats del continu de l'especiació, i.e. l'estudi de les relacions entre poblacions. Aquesta aproximació s'ha usat com a marc (1) per fer hipòtesis taxonòmiques fonamentades i (2) per extreure pistes sobre els mecanismes que dirigeixen l'especiació. Com a resultat, hem descrit i proposat diversos casos de tàxons que havien passat desapercebuts o que s'havien dividit excessivament. Documentem l'existència de tres tipus de mecanismes productors de diversitat en papallones: deriva, selecció i hibridació. La selecció actuà mitjançant l'adaptació a factors ambientals biòtics, que causaren desplaçament de caràcters reproductius, canvi de planta nutrícia i a\ll ocronia produïda per l'adaptació al període de floració de la planta nutrícia. Addicionalment, les tècniques genètiques emprades són avaluades i els seus avantatges i inconvenients discutits.
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Mnguni, Sandiso. "Reproductive isolation mechanisms of two cryptic species of Eccritotarsus (Hemiptera: Miridae), biological control agents of water hyacinth, Eichhornia crassipes (Martius) Solms-Laubach (Pontederiaceae)." Thesis, Rhodes University, 2019. http://hdl.handle.net/10962/68133.
Full textAbstract:
Water hyacinth, Eichhornia crassipes (Martius) Solms-Laubach (Pontederiaceae), is one of the world’s worst alien invasive plants. It is indigenous to the Amazon basin in South America but has become a problematic alien invasive in other parts of the world. As such, several host-specific biological control agents have been sourced from the native distributions in South America and have been released to control this plant where it has become problematic. Two of these agents include the geographically and reproductively isolated cryptic species of Eccritotarsus (Hemiptera: Miridae). One of these species was collected in the upper reaches of the Amazon River in Peru, while the other was collected over 3500km away from that site, in Florianopolis, southern Brazil. These cryptic species were thought to be a single species until recently, when DNA barcoding indicated that they were likely to be two species, and the species status has now been confirmed by interbreeding experiments and detailed morphological studies. The Brazilian population remains Eccritotarsus catarinensis (Carvalho), while the Peruvian population is now known as Eccritotarsus eichhorniae (Henry). The aim of this project was to investigate the mating behaviour and other behavioural traits of the two species that have resulted in reproductive isolation, and which could have led to speciation. In addition, investigations involving analysis of chemical compound compositions of the two species aimed to determine the extent to which the compounds played a role in the development and maintenance of reproductive isolation. To achieve the aims, behavioural-observation experiments were conducted in the form of no-choice, bi-choice and multi-choice tests in 1:1, 2:1 and 3:1 sex ratio assessments, both within and between species. Chemical compound compositions of E. catarinensis and E. eichhorniae were also assessed using Nuclear Magnetic Resonance (NMR), Solid-phase micro-extraction (SPME) and Gas-Chromatography Mass-Spectrometry (GC-MS) techniques. In no-choice experiments, the highest number of single and multiple copula incidences, and average total copula duration was found within species while copulation between species was much rarer. In bi-choice experiments, E. eichhorniae females and E. catarinensis males only chose to mate with their respective conspecifics, and within species copulations continued to have higher average total copula duration. In multi-choice experiments, the highest number of single and multiple copula incidences and average total copula duration was also found within species. GC-MS analysis suggested that E. catarinensis females and E. eichhorniae males have unique chemical compounds missing in their conspecifics and same sex of the other species. Further analysis suggested that E. catarinensis females and E. eichhorniae males have similar chemical compound compositions, whereas as E. eichhorniae females and E. catarinensis males have similar chemical compound compositions. These results suggest that there are behavioural differences that led to the development and maintenance of prezygotic reproductive isolation mechanisms, and that this is probably driven by pheromones in chemical compound compositions. These two species were geographically isolated in the native range and the populations have diverged to the point that they are now reproductively incompatible and therefore, distinct species. The main driver of the speciation is most likely mate recognition and attraction, as only reproductively important traits such as pheromones, genitalia, the scent glands and antennae have changed, while other traits, including host range and morphology, have remained remarkably stable. This provides evidence that differences in sexual selection in isolated populations may be important drivers of speciation and reproductive isolation in cryptic species.
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Haponski, Amanda E. "Molecular, morphological, and biogeographic resolution of cryptic taxa in the Greenside Darter Etheostoma blennioidescomplex." Connect to full text in OhioLINK ETD Center, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=toledo1196866050.
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Thesis (M.S.)--University of Toledo, 2007.Typescript. "Submitted as partial fulfillment of the requirements for The Master of Science Degree in Biology (Ecology-track)." "A thesis entitled"--at head of title. Bibliography: leaves 35-47.
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Lintott, P. R. "The distribution and habitat preferences of bats in a temperate urban landscape." Thesis, University of Stirling, 2015. http://hdl.handle.net/1893/22229.
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Urbanisation is a key driver in the loss, fragmentation and modification of natural habitats resulting in the global loss of biodiversity. As the human population, and consequently the rate of urbanisation, continues to increase exponentially it is important to understand how to sustain and enhance biodiversity within the built environment. Cities comprise a complex assortment of habitat types yet relatively little is known of how its composition and spatial configuration can influence species presence or foraging activities. It is therefore necessary to examine habitat use and biodiversity patterns at multiple spatial scales to fully understand how species are responding to the urban matrix. There are few other orders of animals that are as strongly associated with people as bats (Chiroptera); for some bat species human habitations provide roosts and adaptations of the environment provide food sources. However bat species richness generally declines with increasing urbanisation indicating that many species are not able to persist in highly urbanised areas. In this thesis, I show that the behaviour, habitat preferences, and distribution of bats are strongly influenced by the built environment at both a local and landscape scale. Although many animal species are known to exhibit sex differences in habitat use, adaptability to the urban landscape is commonly examined at the species level without consideration of potential intraspecific differences. I found that female Pipistrellus pygmaeus show greater selectivity in foraging locations within urban woodland in comparison to males at both a local and landscape scale. There was a lower probability of finding females within woodlands which were poorly connected, highly cluttered, with a high edge: interior ratio and fewer mature trees. The results have important implications for our understanding of how to manage areas for breeding females and highlight the need to supplement acoustic monitoring with trapping data to assess sex differences in habitat use. Determining how morphological or behavioural traits can influence species adaptability to the built environment may enable us to improve the effectiveness of conservation efforts. The morphological similarities between P. pygmaeus and P. pipistrellus suggest that both species should respond similarly to the urban matrix, however I found differential habitat use occurring within a variety of urban habitats (e.g. woodland and waterways) and at a landscape scale. In urban woodland there was a higher probability of P. pygmaeus activity relative to P. pipistrellus in woodlands with low clutter and understory cover which were surrounded by low levels of built environment. Many bat species are strongly associated with aquatic or adjacent riparian habitats yet we know little about the utilisation of urban waterways by bats. After surveying urban waterways throughout the UK, I was able to show that the built environment can negatively affect a variety of bat species from the riparian zone up to 3km from a waterway. This indicates that beneficial urban waterway rehabilitation schemes for bats require management at multiple spatial scales, from retaining a vegetated riparian zone at the local scale to highlighting the necessity for conservation funding to be spent on the implementation of landscape scale environmental improvement schemes that encompass the entire urban matrix. Undertaking surveys to confirm species presence or to estimate population sizes can be difficult, particularly for elusive species such as bats. I was able to demonstrate a variety of ways to increase surveying efficiency (e.g. the use of an acoustic lure to increase bat-capture rate) and a significant relationship between bat activity and the relative abundance of certain species of bat which can maximise the knowledge of diversity in an area whilst minimising wildlife disturbances. Urbanisation has also had strong negative effects on many insect groups, such as moths, which are important components of the diets of many bat species. I found that woodland vegetation characteristics were more important than the surrounding landscapes in determining the abundance, species richness, and species diversity of moth assemblages within urban woodland. This indicates that management at a local scale to ensure provision of good quality habitat may be more beneficial for moth populations than improving habitat connectivity across the urban matrix. The findings presented in this thesis have important implications for our understanding of the adaptability of species to the built environment and for the management and monitoring of bat populations. It also highlights that even common bat species are negatively affected by urbanisation and much greater attention should be paid to securing their future within the urban landscape.
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Alexander, Callan. "Passive acoustic monitoring of Australia’s largest owl: Using automatic species recognition to detect the powerful owl (Ninox strenua)." Thesis, Queensland University of Technology, 2022. https://eprints.qut.edu.au/227461/1/Callan_Alexander_Thesis.pdf.
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This thesis utilises passive acoustic monitoring as a framework to study Powerful Owls (Ninox strenua) in south-east Queensland. The study quantitively describes the vocalisations of adult and chick Powerful Owls and utilises open-source machine learning software to create automated species recognition tools for use in citizen science programs. The results indicate that call characteristics historically used to sex adult Powerful Owls are likely unreliable. Testing of the automated call recognisers resulted in highly promising outcomes, which suggests that they are likely to be valuable tools for future study.
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Stigenberg, Julia. "Hidden Creatures – systematics of the Euphorinae (Hymenoptera)." Doctoral thesis, Stockholms universitet, Zoologiska institutionen, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-87904.
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Parasitic wasps constitute one of the last remaining frontiers in the charting of animal diversity. The Braconidae is the second most species-rich family of parasitic wasps; the world fauna has been estimated at 40 000 species and the Swedish fauna is believed to include a little more than 2 000 species, 1 200 of which are currently documented. This thesis is a contribution to the rapidly increasing knowledge of braconid diversity. In paper I, a new gregarious parasitoid, Meteorus acerbiavorus sp. nov. (Braconidae: Eupohrinae), is described from specimens reared from the cocoons of the butterfly Acerbia alpina (Quensel) (Lepidoptera, Arctiidae) in northwestern Finnish Lapland. Based on a molecular phylogenetic analysis, the new species is shown to belong to the M. rubens species group. In the second paper, the Western Palearctic fauna of the tribe is revised, seven new species are described and a key to the Western Palearctic species is presented. Two molecular markers, 28S and COI, are used to study phylogenetic relationships in the tribe. The molecular results showed that the Meteorini fall into four well supported clades. The results also reveal a considerable cryptic species diversity. The third paper deals with distributional, phenological and in many cases rearing data from nearly 2 500 specimens (44 species) of the Meteorini in the collection of the National Museums of Scotland (NMS), Edinburgh. Patterns in the breadth of host ranges are discussed in relation to a reiterated speciation hypothesis. Paper IV examines the phylogenetic relationships of the entire subfamily Euphorinae based upon four gene regions (18S, CAD, 28S D2, and COI). A revised classification of the Euphorinae is proposed that recognizes 55 genera and 14 tribes. Our study shows that early members of the Euphorinae were parasitoids of coleopteran larvae, with a host shift to larval Lepidoptera, adult or immature hosts in the Hemiptera, Hymenoptera, Neuroptera, Orthoptera and Psocoptera.At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: In press. Paper 4: Manuscript.
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Paula, Thiago Silva de. "O Complexo Cliona celata Grant, 1826 (Porifera, Demospongiae) na América do Sul: uma abordagem molecular e morfológica." Universidade do Estado do Rio de Janeiro, 2009. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=2414.
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Este trabalho visou a averiguação do status taxonômico das esponjas bioerosivas do complexo Cliona celata da América do Sul por meio de técnicas moleculares, utilizando como marcadores a subunidade I da Citocromo c oxidase (cox1) e os Espaçadores Internos Transcritos do RNAr nuclear (ITS1 e ITS2), além de testar outros marcadores. Igualmente, avaliou o grau de variabilidade morfológica encontrado nessas espécies, principalmente por meio da morfometria dos tilóstilos, a fim de estabelecer uma diagnose para elas. Ainda, tentou determinar as relações filogenéticas dessas espécies com as demais esponjas bioerosivas utilizando o gene 28S do RNAr nuclear. Foi possível determinar a existência de cinco clados de esponjas bioerosivas do complexo Cliona celata para a América do Sul, e dois outros clados não-sulamericanos, por meio dos marcadores moleculares utilizados. Embora seja discutida a validade desses clados como espécies distintas, continua impossível, por meio de
caracteres morfológicos, distingui-los, e dessa forma, a proposição formal de novas espécies é evitada. Através da reconstrução filogenética do grupo, é possível verificar que as esponjas bioerosivas analisadas se apresentaram como um grupo monofilético, e se separa em três principais clados: Pione, Spirastrellidae, e Clionaidae. Por meio desta, é sugerida a alocação das espécies do complexo C. viridis e C. schimidti dentro de Spirastrella, além de ser necessária a criação de um novo gênero para alocar as espécies do novo complexo identificado aqui, o complexo C. delitrix.This work intended the validation of the taxonomic status of boring sponges from the Cliona celata complex of South America by molecular techniques, using Cytochrome coxidase, subunit I (cox1), and Internal Transcribed Spacers (ITS) of rRNA nuclear genes as molecular markers. Additionally, the degree of morphological variation necessary to establisha correct diagnosis for the studied species was evaluated, and additional markers were tested. Finally, a phylogenetic analysis comparing this species with other boring sponges, using the 28S rRNA nuclear gene was carried out. It was possible to point out the existence of five clades of boring sponges from the C. celata complex in South America, and two more from Mexico and Australia. Although these clades can comprise new valide species, no morphological evidence was found to separate them, and thus, no formal species descriptions were presented. Through out phylogenetic analyses it was possible to conclude that boring sponges form a monophyletic group, which can be separated in three clades: Pione, Spirastrellidae, and Clionaidae. This work suggests to allocate C. viridis and C. schimidti species complexes inside Spirastrella, and to create a new genus for the new C. delitrix species complex.