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Rothermel, Betsie. "Movement behavior, migratory success, and demography of juvenile amphibians in a fragmented landscape /". free to MU campus, to others for purchase, 2003. http://wwwlib.umi.com/cr/mo/fullcit?p3099626.
Pełny tekst źródłaPatrick, David A. "The Effects of Forest Practices on a Maine Amphibian Community". Fogler Library, University of Maine, 2007. http://www.library.umaine.edu/theses/pdf/PatrickDA2007.pdf.
Pełny tekst źródłaCrockett, Marquette Elaine. "Survey and Comparison of Amphibian Assemblages in Two Physiographic Regions of Northeast Tennessee". [Johnson City, Tenn. : East Tennessee State University], 2001. http://etd-submit.etsu.edu/etd/theses/available/etd-0605101-155522/unrestricted/crockett0611.pdf.
Pełny tekst źródłaRegula, Meyer Lisa. "Invasive plants and native amphibians| The implications for amphibian conservation in eastern North America". Thesis, Kent State University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3618851.
Pełny tekst źródłaHumans introduce non-native plants to new areas at an increasing rate with the increased movement across the globe. These invasive species can become mono-cultures and extremely different from the native floral community. Amphibians, at the same time, are facing global declines with approximately one-third of all amphibians threatened or endangered. Due to the importance of amphibians as prey items for many vertebrates including small birds, mammals, and reptiles, and also predator controls over many invertebrates, including some pest species, the decline of amphibians has large implications for many environments. This study looks at a range of interactions between two invasive plants ( Typha angustifolia and Phragmites australis) and two native anurans (Lithobates clamitans and Lithobates catesbeianus).
As ecosystem engineers, plants form the basis of many communities, and sculpt the physical environment by adding complexity to the earth's surface. They also add chemical constituents either actively or passively too ward off other competitors. This change in the environment on both the chemical and physical level leads to complex possibilities for a changed plant community to impact the rest of the ecosystem, including amphibians. I focus on the physical changes by looking at behavior of amphibians in these invasive plant mono-cultures and non-invaded controls, and their appearance in invaded and non-invaded wetlands, both constructed and naturally occurring. On the chemical side of the matter, I monitor water chemistry measures in natural and constructed wetlands that are either lacking invasive plants or have a substantial presence of these plants, and correlate those measures with tadpole growth and survival.
Regula, Meyer Lisa K. "INVASIVE PLANTS AND NATIVE AMPHIBIANS: THE IMPLICATIONS FOR AMPHIBIAN CONSERVATION IN EASTERN NORTH AMERICA". Kent State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=kent1384952870.
Pełny tekst źródłaSchneider, Amy Elizabeth. "Continued study of the use of created ponds for amphibian breeding in fragmented forested areas". [Huntington, WV : Marshall University Libraries], 2008. http://www.marshall.edu/etd/descript.asp?ref=876.
Pełny tekst źródłaRegosin, Jonathan V. "Terrestrial habitat use by pool-breeding amphibians in a suburban landscape /". Thesis, Connect to Dissertations & Theses @ Tufts University, 2003.
Znajdź pełny tekst źródłaAdviser: J. Michael Reed. Submitted to the Dept. of Biology. Includes bibliographical references (leaves 124-134). Access restricted to members of the Tufts University community. Also available via the World Wide Web;
Penner, Johannes. "Macroecology of West African amphibians". Doctoral thesis, Humboldt-Universität zu Berlin, Lebenswissenschaftliche Fakultät, 2014. http://dx.doi.org/10.18452/17035.
Pełny tekst źródłaAmphibian populations are declining globally. For informed conservation decisions a sound scientific background is needed. One major component is species distribution and the underlying causes. This also requires clarity on the taxonomic status. Often neglected regions are located in the tropics. In order to fill this gap, the present thesis examines the macroecology of West African amphibians. A new species of the family Phrynobatrachidae is described. Afterwards, the taxonomic differences between morphologically similar members of the families Hyperoliidae and Arthroleptidae are discussed. Beside other studies, this sets the field for macroecology. It is tested whether West Africa is a unique biogeographic region. The similarity of amphibian assemblages from Sub-Saharan Africa is analysed and it is shown that West Africa contains unique assemblages. Similarities within the region are higher than similarities between habitats across different regions. The main barrier towards Central Africa is the Cross River. Several geographic divisions within West Africa are detected. It is examined whether the chytrid fungus Batrachochytrium dendrobatidis (Bd), one important factor for amphibian population declines in many other regions, occurs in West Africa. So far there is no positive record west of Nigeria. However, models predict that environmental suitability for Bd is high. The most plausible explanation for the absence is that the Dahomey Gap acted as a natural barrier against the spread of the Bd. Finally, the niches of West African amphibians are investigated. For most species environmental niche models are calculated. This confirms previously known areas of high alpha diversity and so far unknown species rich areas are detected. In a further study, explanations for differing range sizes are searched for. Niche breadth is commonly assumed to be the general cause. However, the analysed data also suggests that dispersal ability can also explain the observed pattern.
Lau, Kwan-wa. "Cloning and characterization of the first amphibian secretins and secretin receptor functional implication of secretin with orexin in amphibians /". Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B44143655.
Pełny tekst źródłaMcMaster, Kellie Anne. "Ecophysiology of Australian cocooning and non-cocooning, burrowing, desert frogs /". Connect to this title, 2006. http://theses.library.uwa.edu.au/adt-WU2007.0138.
Pełny tekst źródłaLau, Kwan-wa, i 劉君華. "Cloning and characterization of the first amphibian secretins and secretin receptor: functional implication ofsecretin with orexin in amphibians". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B44143655.
Pełny tekst źródłaHopkins, Samantha. "Chytridiomycosis in amphibian populations in the Western Cape, South Africa". Thesis, University of the Western Cape, 2002. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_7137_1359702947.
Pełny tekst źródłaThere have been many cases reported of amphibian populations declining. These are often due to anthropogenic factors such as habitat destruction and pollution. However, some eclines have not had an obvious cause and many of these have been investigated and found to be due to pathogenic disease. Batrachochytrium dendrobatidis is a recently described pathogen of frogs. The population declines that have been associated with chytridiomycosis have occurred in relatively undisturbed areas such as national parks. The declines tend to occur at higher altitudes or in colder climates. This is thought to be because of the frog immune system being slower at lower temperatures. This project gives an overview of chytrid infection in the Western Cape and at a small number of sites in the Northern Cape and Eastern Cape.
White, Steve. "Population trends, conservation and the trade in amphibians in Asia". Thesis, View the Table of Contents & Abstract, 2005. http://sunzi.lib.hku.hk/hkuto/record/B34737364.
Pełny tekst źródłaRuthsatz, Katharina [Verfasser], i Kathrin H. [Akademischer Betreuer] Dausmann. "Amphibians in a changing world : an ecophysiological perspective on amphibian metamorphosis / Katharina Ruthsatz ; Betreuer: Kathrin H. Dausmann". Hamburg : Staats- und Universitätsbibliothek Hamburg, 2019. http://d-nb.info/1176702076/34.
Pełny tekst źródłaMcmahon, Taegan A. "Understanding Amphibian Decline: the Role of Pesticides and the Pathogenic Chytrid Fungus on Amphibians and Aquatic Communities". Scholar Commons, 2013. http://scholarcommons.usf.edu/etd/4727.
Pełny tekst źródłaRuthsatz, Katharina Verfasser], i Kathrin H. [Akademischer Betreuer] [Dausmann. "Amphibians in a changing world : an ecophysiological perspective on amphibian metamorphosis / Katharina Ruthsatz ; Betreuer: Kathrin H. Dausmann". Hamburg : Staats- und Universitätsbibliothek Hamburg, 2019. http://nbn-resolving.de/urn:nbn:de:gbv:18-95339.
Pełny tekst źródłaZainab, Tayyaba. "A study of parapinopsin in amphibians". Thesis, King's College London (University of London), 2014. http://kclpure.kcl.ac.uk/portal/en/theses/a-study-of-parapinopsin-in-amphibians(d10ebd14-a9be-4efc-a8b5-ebca004fb11d).html.
Pełny tekst źródłaMaddock, S. T. "Systematics and phylogeography of Seychelles amphibians". Thesis, University College London (University of London), 2016. http://discovery.ucl.ac.uk/1476198/.
Pełny tekst źródłaPulliam, Robert. "Evolutionary history of amphibians in biodiversity hotspots". Connect to resource, 2006. http://hdl.handle.net/1811/6021.
Pełny tekst źródłaTitle from first page of PDF file. Document formattted into pages: contains 32 p.; also includes graphics. Includes bibliographical references (p. 17-19). Available online via Ohio State University's Knowledge Bank.
Fröbisch, Nadia. "Ontogeny and phylogeny of small dissorophoid amphibians". Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=22015.
Pełny tekst źródłaCette étude envisage l'ontogénie et la phylogénie des branchiosaurides et amphibamides, des petits amphibiens dissorophoïdes du Carbonifère supérieur et du Permien inférieur. Les deux clades jouent un rôle central dans le débat qui considère les liens et les origines des trois groups d'amphibien modern parmi les possibles antécédents du Paléozoïque. Les branchiosaurides possèdent un record exceptionnel de fossiles comportant des centaines de spécimens et plusieurs étapes ontogéniques. Ceci a permis une étude détaillée à propos de la séquence d'ossification des membres du branchiosauride, Apateon. Ce dernier montre que les branchiosaurides partagent avec les salamandres modernes la caractéristique unique d'une dominance préaxiale dans le développement des membres. Une révision détaillée de la littérature concernant les différentes formes d'ossification des membres chez les tétrapodes, modernes et fossilisés, forme la base pour cette investigation. Ceci est réalisé en montrant que la séquence d'ossification parmi les tétrapodes marque le patron général de la squelettogenèse dans les premières étapes du développement. En outre, la préservation spectaculaire des étapes ontogénétiques parmi les branchiosaurides simplifie l'identification de deux cycles biologique, la néoténie et la métamorphose. La plupart des branchiosaurides sont néoténique, pourtant quelques membres de l'espèce, Apateon gracilis, ont été reconnus comme étant complètement métarmorphosés en adultes terrestres. Cette métamorphose a eu lieu durant une courte période de temps, et elle représente la première évidence d'une métamorphose condensée, hors des groups d'amphibien modern. Contrairement aux branchiosaurides, les amphibamides comportent des tétrapodes terrestres qui possèdent une bonne ossification des membres et de la boîte crânienne. Un nouveau genre et nouvelle espèce d'un amphibamide de la fissure de Fort Sill sont ici dé
Wood, Laura R. "Diversity and distribution of amphibians in Luxembourg". Thesis, University of Kent, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.544084.
Pełny tekst źródłaRollins, Hilary Byrne. "Ecological Effects of Climate Change on Amphibians". Case Western Reserve University School of Graduate Studies / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=case1559915081386624.
Pełny tekst źródłaBielby, Jon. "Extinction risk and population declines in amphibians". Thesis, Imperial College London, 2008. http://hdl.handle.net/10044/1/4278.
Pełny tekst źródłaCarey, Marc Brandon. "Brainstem auditory evoked potentials in anuran amphibians". PDXScholar, 1992. https://pdxscholar.library.pdx.edu/open_access_etds/4267.
Pełny tekst źródłaEnright, Lisa. "Effects of selection logging on amphibian diversity and abundance in shade-tolerant hardwood forests of Algonquin Provincial Park, Ontario". Connect to this title online, 1998. http://www.nlc-bnc.ca/obj/s4/f2/dsk2/ftp03/MQ35886.pdf.
Pełny tekst źródłaGahl, Megan K. "Spatial and Temporal Patterns of Amphibian Disease in Acadia National Park Wetlands". Fogler Library, University of Maine, 2007. http://www.library.umaine.edu/theses/pdf/GahlMK2007.pdf.
Pełny tekst źródłaGross, Lee M. "Long-term assessment of predatory fish removal on a pond-breeding amphibian community in central Illinois /". View online, 2009. http://repository.eiu.edu/theses/docs/32211131565136.pdf.
Pełny tekst źródłaOrton, Frances. "Investigation into the effects of pesticides on amphibians". Thesis, Brunel University, 2008. http://bura.brunel.ac.uk/handle/2438/2456.
Pełny tekst źródłaWombwell, Emma Louise. "Emerging infectious disease and the trade in amphibians". Thesis, University of Kent, 2014. https://kar.kent.ac.uk/48014/.
Pełny tekst źródłaMichaels, Christopher. "Evidence based ex situ husbandry for captive amphibians". Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/evidence-based-ex-situ-husbandry-for-captive-amphibians(54a41c4e-a6cb-471c-8c16-ef012f61cd35).html.
Pełny tekst źródłaWard, Rocky. "Multivariate Analyses of Amphibian and Reptilian Distribution in Texas". Thesis, University of North Texas, 1988. https://digital.library.unt.edu/ark:/67531/metadc331167/.
Pełny tekst źródłaJames, Stacy M. "Amphibian metamorphosis and juvenile terrestrial performance following chronic cadmium exposure in the aquatic environment". Diss., Columbia, Mo. : University of Missouri-Columbia, 2005. http://hdl.handle.net/10355/4140-D1763/.
Pełny tekst źródłaThe entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (May 24, 2006) Vita. Includes bibliographical references.
Cowman, Deborah Fay. "Pesticides and amphibian declines in the Sierra Nevada Mountains, California". Diss., Texas A&M University, 2005. http://hdl.handle.net/1969.1/4770.
Pełny tekst źródłaBadawy, Gamal Metwally. "Development of the gastro-intestinal regulation in the axolotl (Ambystoma mexicanum)". Thesis, University of Birmingham, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.273975.
Pełny tekst źródłaDinehart, Simon K. "The effects of Disturbance on Aquatic Breeding Amphibians within the Cuyahoga Valley National Park". University of Akron / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=akron1133815626.
Pełny tekst źródłaNorthrop, Robert John. "Development and assessment of a wildlife habitat relationship model for terrestrial vertebrates in the state of Maryland". Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 152 p, 2009. http://proquest.umi.com/pqdweb?did=1885544331&sid=2&Fmt=2&clientId=8331&RQT=309&VName=PQD.
Pełny tekst źródłaTufts, Bruce Laurie. "Ion exchange mechanisms for the control of volume and pH in fish and amphibian erythrocytes". Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/29443.
Pełny tekst źródłaScience, Faculty of
Zoology, Department of
Graduate
Faruk, Aisyah. "The impact of oil palm conversion on tropical amphibians". Thesis, Queen Mary, University of London, 2013. http://qmro.qmul.ac.uk/xmlui/handle/123456789/8458.
Pełny tekst źródłaMcConville, J. R. "Brain Mechanisms Associated with Motivation in Amphibians and Fish". Thesis, Queen's University Belfast, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.501325.
Pełny tekst źródłaMarques, Sérgio Miguel Reis Luís. "Gene expression in understanding mechanisms of toxicity in amphibians". Doctoral thesis, Universidade de Aveiro, 2011. http://hdl.handle.net/10773/8257.
Pełny tekst źródłaDe uma forma geral os anfíbios são conhecidos como organismos que apresentam uma grande sensibilidade a vários tipos de contaminantes. Contudo existem casos, como o de Pelophylax perezi (rã-verde), em que estes organismos habitam áreas extremamente contaminadas. Este facto verifica-se na mina de urânio desactivada, da Cunha Baixa (Viseu, centro de Portugal), em que uma população destas rãs habita na lagoa de efluente ácido mineiro (M). Estudos ecotoxicológicos anteriores com estes organismos revelaram apenas efeitos de toxicidade ténues levantando algumas questões. Com o objectivo de elucidar quais os mecanismos que permitem a P. perezi permanecer neste local, sem sofrer aparentemente efeitos perniciosos, encetamos este trabalho. Numa primeira abordagem, avaliámos o sistema de defesa antioxidante de rãs adultas, bem como o conteúdo em metais de alguns órgãos. Desta forma verificámos alterações enzimáticas, principalmente no pulmão e acumulação de metais nos vários órgãos. Posteriormente foi realizado um estudo de expressão genética diferencial, também em organismos adultos e desta feita foram sugeridos alguns mecanismos de protecção basal que estarão por detrás da capacidade de suportar este ambiente extremamente contaminado. Numa etapa seguinte abordámos os efeitos em fases larvares, fazendo inicialmente uma exposição in situ, a vários efluentes, caracteristicamente diferentes, do complexo mineiro. Avaliámos o crescimento, a acumulação de metais e a actividade de alguns biomarcadores de stress oxidativo. Como resultado pudemos constatar que nas fases larvares para além de alguma mortalidade existe acumulação de metais bem como algumas alterações a nível de biomarcadores de stress oxidativo. Numa última abordagem realizamos uma exposição crónica dos girinos a efluente da mina com diversos níveis de pH para distinguir os efeitos da toxicidade do pH, dos efeitos da toxicidade pelo conteúdo de metais. Para tal avaliámos novamente biomarcadores de stress oxidativo, crescimento, acumulação de metais e efectuamos ainda um estudo de expressão genética diferencial. Esta última aproximação permitiu verificar que a toxicidade do efluente resulta primariamente do pH ácido, assumindo a contaminação por metais um papel secundário. Contudo o crescimento dos girinos de P. perezi apresenta-se estimulado por pHs mais baixos. São apontados ainda alguns mecanismos, em girinos, para lidar com o stress causado pela contaminação por metais.De uma forma geral pôde-se constatar que quer anfíbios adultos quer girinos expostos ao efluente apresentam valores altos de metais acumulados. Os biomarcadores de stress oxidativo na sua maioria não apresentaram respostas coerentes mediante as várias exposições. Este trabalho apresentase como um contributo importante para a ecotoxicologia de anfíbios, aumentando os níveis actuais de conhecimento sobre o efeito de contaminação proveniente de efluentes mineiros, sugerindo ainda mecanismos de resistência quer em larvas, quer para adultos.
Amphibians are generally known as organisms that present a great sensitivity to several kinds of contaminants. However, there are some cases as the one of Pelophylax perezi (green frog), where these organisms inhabit extremely contaminated areas. This fact has been recorded, in the deactivated uranium mine of Cunha Baixa (Viseu, Centre of Portugal) where a frogs’ population inhabits the acid mine effluent (M). Previous ecotoxicological studies carried out with these organisms have revealed only mild toxic effects. This has raised some questions on these organisms ability to endure extreme conditions, gaining certainly some advantage in these places in terms of refuge. Aiming to uncover the mechanisms that allow the presence of P. perezi in this area without apparent deleterious effects, this work was carried out. A first approach was to assess the antioxidant defence system in frogs as well as metal content in various organs. Thus enzymatic changes, mainly in lung, and metal accumulation were reported. Afterwards a differential gene expression study was also performed in adult organisms and basal protection mechanisms were suggested as supporting the ability of enduring extremely contaminated environment. These mechanisms encompass the possible increase of the albumin and fibrinogen antioxidants. In the next stage effects on larvae were addressed with an in situ exposure to several mine complex effluents with different characteristics. Growth, metal accumulation and oxidative stress biomarkers were assessed. As a result we can point that in the larval stages, beyond mortality, metal accumulation exists, as well as some oxidative stress enzyme responses. In a final approach, to distinguish metal toxicity effects from pH toxicity effects, tadpoles were exposed chronically to the mine effluent at various pH values. With this purpose, oxidative stress biomarkers, growth, metal accumulation and differential gene expression were performed. This approach allowed verifying that the effluent toxicity results primarily from acidic pH, with metal contamination assuming a secondary role. However P. perezi tadpoles’ growth seems to be stimulated by lower pH values. Some mechanisms in tadpoles are pointed as a way to cope with metal contamination stress. These mechanisms include an increase in osmotic regulation and energy acquisition investment. Overall, it could be noted that both adult amphibians and tadpoles exposed to the effluent have higher metal accumulation. Also the majority of the oxidative stress biomarkers did not present consistent responses throughout the various exposure conditions. This work presents as a new contribution for amphibian ecotoxicology, increasing current knowledge on mine effluent contamination effects and suggesting resistance mechanisms both in larvae and adults.
Marques, Mariana Pimentel. "Geographical distribution of the amphibians and reptiles of Angola". Master's thesis, Universidade de Évora, 2015. http://hdl.handle.net/10174/13275.
Pełny tekst źródłaKluthe, Gregory Joseph. "Relative Heart Ventricle Mass and Cardiac Performance in Amphibians". PDXScholar, 2012. https://pdxscholar.library.pdx.edu/open_access_etds/920.
Pełny tekst źródłaVasconcelos, Daniel. "Amphibian and Vegetation Dynamics in a Restored Wetland in Maine". Fogler Library, University of Maine, 2003. http://www.library.umaine.edu/theses/pdf/VasconcelosD2003.pdf.
Pełny tekst źródłaCallison, Catherine Mary. "Factors Influencing Oviposition Among Pond-Breeding Amphibians: Exotic Vegetation, Oviposition Braces, and Cover". PDXScholar, 2001. https://pdxscholar.library.pdx.edu/open_access_etds/4333.
Pełny tekst źródłaCunningham, Jesse. "Pond-Breeding Amphibian Species Distributions in a Beaver-Modified Landscape, Acadia National Park, Mount Desert Island, Maine". Fogler Library, University of Maine, 2003. http://www.library.umaine.edu/theses/pdf/CunninghamJ2003.pdf.
Pełny tekst źródłaBlomquist, Sean Michael. "Relative Fitness and Behavioral Compensation of Amphibians in a Managed Forest". Fogler Library, University of Maine, 2008. http://www.library.umaine.edu/theses/pdf/BlomquistSM2008.pdf.
Pełny tekst źródłaFavero, Eduardo Rondelli. "Caracterização citogenetica de especies e populações de Pseudopaludicola (Leiuperidae, Anura)". [s.n.], 2008. http://repositorio.unicamp.br/jspui/handle/REPOSIP/317990.
Pełny tekst źródłaDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: O gênero Pseudopaludicola, pertencente à família Leiuperidae, compreende atualmente 12 espécies de rãs de pequeno tamanho, distribuídas pela América do Sul, sendo a ocorrência de oito delas foi relatada para o Brasil. Devido à grande semelhança morfológica entre espécies, algumas ocorrendo em simpatria, confusões taxonômicas são freqüentes. Alguns estudos morfológicos acerca deste gênero foram realizados, mas as relações de parentesco inter- e intragenéricas de Pseudopaludicola permanecem pouco esclarecidas. As poucas informações citogenéticas para o gênero Pseudopaludicola restringiam-se apenas à determinação do número de cromossomos e análise do cariótipo por métodos de coloração convencional. Para Pseudopaludicola falcipes, em especial, foi descrita uma variação intra-específica do número de cromossomos, de 2n=16 à 2n=20. O presente estudo visa contribuir com dados citogenéticos para a caracterização de espécies de Pseudopaludicola e para o entendimento dos processos envolvidos na evolução cariotípica do gênero. Foram analisados os cariótipos de exemplares de Pseudopaludicola falcipes, P. ameghini (sensu Cope, 1887) e P. mystacalis de suas respectivas localidades-tipo (região de Porto Alegre, RS e Chapada dos Guimarães, MT), de P. mystacalis e de P. ternetzi, de Uberlândia (MG), de Pseudopaludicola aff. falcipes I, II, III e IV, da região noroeste do estado de São Paulo (municípios de Santa Fé do Sul, Vitória Brasil, Palestina e Icém), de Pseudopaludicola aff. mystacalis I, II, III e IV, dos municípios de Icém (SP), Barreirinhas (MA) e Urbano Santos (MA) e Pseudopaludicola sp. 1, 2 e 3, sendo as duas primeiras provenientes de Poconé (MT) e a terceira de Santa Terezinha (MT). As metáfases foram obtidas de suspensões de células de epitélio intestinal e testículo, e coradas com Giemsa ou submetidas às técnicas impregnação por prata (Ag-NOR) para detecção de NOR e de bandamento C, para a localização de heterocromatina. Os dados obtidos revelaram uma variação interespecífica quanto ao número de cromossomos. Dentre os espécimes provenientes de Poconé, MT, havia dois cariótipos distintos, com 2n=22 e com 2n=16 cromossomos (Pseudopaludicola sp. 1 e 2) e os de Icém, SP, com indivíduos 2n=20 e 2n=16 cromossomos (Pseudopaludicola aff. mystacalis, respectivamente I e II). Pseudopaludicola falcipes e Pseudopaludicola sp.1, de Poconé, apresentaram 2n=22 e a NOR localizada na região pericentromérica do braço longo do par 8. Estas espécies diferiram, na morfologia da NOR, sendo heteromórfica em P. falcipes e homomórfica em Pseudopaludicola sp. 1, e na localização de algumas bandas heterocromáticas. Pseudopaludicola ameghini (sensu Cope, 1887), P. ternetzi e Pseudopaludicola aff. mystacalis I de Icém apresentaram 2n=20 cromossomos e a NOR localizada na região telomérica do braço longo do par 9. O cariótipo de P. ternetzi diferiu do de P. ameghini tanto pela classificação morfológica distinta do par 7 quanto pelo padrão de distribuição de heterocromatina. Pseudopaludicola mystacalis, bem como todos os espécimes de Pseudopaludicola aff. falcipes I, II, III e IV, Pseudopaludicola aff. mystacalis II, III e IV e Pseudopaludicola sp. 2 e 3 apresentaram 2n=16 cromossomos metacêntricos e submetacêntricos, com a NOR localizada na região pericentromérica do braço curto do par 4. Vários espécimes apresentaram um heteromorfismo de tamanho em relação aos homólogos do par 4 (morfo 4 e morfo 4'), alterando a classificação desse cromossomo para metacêntrico em algumas populações. Em P. mystacalis, P. aff. falcipes I, II, III e IV, P. aff. mystacalis II, III e IV e Pseudopaludicola sp 2 e 3 foram detectados blocos de heterocromatina fortemente marcados nas regiões pericentroméricas no braço curto do par 1 e longo do par 2. Os resultados obtidos mostram que P. ameghini (sensu Cope, 1887) com 2n=20 e P. mystacalis com 2n=16, são unidades taxonômicas distintas e que os espécimes tidos como Pseudopaludicola aff. falcipes) e como Pseudopaludicola sp. mostraram-se citogeneticamente relacionados à P. mystacalis e não à P. falcipes que possui 2n=22 cromossomos. Desta forma, os nossos dados sugerem a retirada de P. ameghini da sinonímia de P. mystacalis e reforçam a necessidade de uma revisão taxonômica no gênero.
Abstract: The genus Pseudopaludicola (family Leiuperidae) comprises 12 species of small sized frogs, which are widely distributed in South America. In Brazil, eight species are described within this genus, and several of them are sympatric. The relevant morphological similarities among the Pseudopaludicola species have contributed to the still poor understanding of many aspects of their taxonomy, including inter- and intrageneric relationships. Cytogenetic data on Pseudopaludicola have been restricted to karyotype analyses using conventional Giemsa staining. Variation in intraspecific chromosomal number was described in P. falcipes, ranging from 2n=16 to 2n=20. In the present work, Brazilian Pseudopaludicola species were submitted to cytogenetic analysis aiming at their further characterization and attempting to better understanding the karyotypical evolution of this genus. The analyzed species were Pseudopaludicola falcipes (Porto Alegre, RS), P. ameghini (sensu Cope, 1887) and P. mystacalis (Chapada dos Guimarães, MT), P. mystacalis and P. ternetzi (Uberlândia, MG), P. aff. falcipes I, II, III and IV (respectively from Santa Fé do Sul, Vitória Brasil, Palestina and Icém, SP), P. aff. mystacalis I, II, III and IV (Icém, SP, Barreirinhas, MA, and Urbano Santos, MA), and Pseudopaludicola sp. 1 and sp. 2 (Poconé, MT) and sp. 3 (Santa Terezinha, MT). Metaphases were obtained from suspensions of intestinal epithelium and testicular cells, and stained with Giemsa or submitted to silver staining technique in order to detect the nucleolus organizing regions (Ag-NOR), and C-banding, for heterochromatin localization. The results revealed interspecific chromosomal number variation. In the Pseudopaludicola sp. 1 and 2 specimens (Poconé MT), two distinct karyotypes were identified, respectively with 2n=22 and 2n=16 chromosomes. Within the Pseudopaludicola aff. mystacalis from Icém, SP, the analyzed specimens had 2n=20 and 2n=16 chromosomes, being nominated I and II, respectively. These data clearly indicated two criptic species of Pseudopaludicola within each of those two localities. The P. falcipes and Pseudopaludicola sp.1 (Poconé, MT) had 2n=22 and the NOR was located at the pericentromeric region in the long arm of the pair 8. The species differed in the NOR morphology, which was heteromorphic in P. falcipes and homomorphic in Pseudopaludicola sp.1, as well as in the localization of some C-bands. Pseudopaludicola ameghini (sensu Cope, 1887), P. ternetzi and Pseudopaludicola aff. mystacalis I (Icém, SP) had 2n=20 chromosomes and the NOR was located on the telomeric region in the long arm of the pair 9. The karyotypes of P. ternetzi and P. ameghini differed in the pair 7 morphology and in the heterochromatin distribution pattern. All analyzed specimens of P. mystacalis, P. aff. falcipes I, II, III and IV, P. aff. mystacalis II, III and IV, and Pseudopaludicola sp. 2 and 3, showed 2n=16 chromosomes, which were all metacentric and submetacentric, with the NOR located in the pericentromeric region of the short arm of the pair 4. In several of those specimens, the size heteromorphism of the pair 4 altered, from submetacentric to metacentric, the classification of one of the homologous of that pair. Strong pericentromeric C-bands were detected on the short arm of the pair 1 and on the long arm of the pair 2 in P. mystacalis, P. aff. falcipes I, II, III and IV, P. aff. mystacalis II, III and IV, and Pseudopaludicola sp. 2 and 3. As based on the cytogenetic data, P. ameghini (sensu Cope, 1887), with 2n = 20, and P. mystacalis, with 2n = 16, are distinct taxonomic units, and the specimens formerly identified as P. aff. falcipes and as Pseudopaludicola sp. were indeed cytogenetically closely related to P. mystacalis and not to P. falcipes, which has 2n = 22 chromosomes. Hence, our data suggest that P. ameghini is not a P. mystacalis synonymy and emphasize the importance of a taxonomic review of the genus Pseudopaludicola.
Mestrado
Biologia Celular
Mestre em Biologia Celular e Estrutural
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Pełny tekst źródłaPahkala, Maarit. "Evolutionary ecology of ultraviolet-B radiation stress tolerance in amphibians". Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2001. http://publications.uu.se/theses/91-554-5081-4/.
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