In this study, I looked at the effects of sound level, temperature and dehydration/hypernatremia on the brainstem auditory evoked potential (BAEP) of four species of anuran amphibians (Rana pipiens, Rana catesbeiana, Bufo americanus and Bufo terrestris). The BAEP was used because it allowed me to monitor both the peripheral and central aspects of auditory nervous function simultaneously and over a long period of time.

Thesis (M.S.)--Rutgers University, 2009. / "Graduate Program in Ecology, Evolution and Natural Resources." Includes bibliographical references (p. 41-47).

This study resulted from the identification of gaps in the literature pertaining to the morphological descriptions of the tadpoles occurring at high altitudes in the Drakensberg Mountains in South Africa. These tadpoles are exposed to low temperatures, high desiccation risk, elevated ultraviolet radiation, competition, and predation and inhabit the clear, flowing streams and marsh areas of the mountain. Highly varying environmental conditions caused tadpoles to have considerable intraspecific variation. The high degree of plasticity necessitated extensive descriptive studies of tadpole morphology in order to document intraspecific variation and set up reliable keys for species identification. Specified adaptations to the extreme montane conditions are present in tadpoles of certain species. An especially interesting adaptation is the elygium, a hemispherical pigmented area above the eye, which apparently protects the retina from harmful ultraviolet radiation. There are no known studies of elygium plasticity in tadpole eyes in relation to variation in ultraviolet radiation. Particular attention was given to the functionality and cytology of this structure. Detailed measurements of tadpoles of six frog species of the high altitude Drakensberg Mountains were made. Morphological adaptations were described on the basis of these measurements. The cytological origin of the elygium of Amietia vertebralis was revealed through histological and cellular ultrastructure studies. The change in elygium morphology over time was studied as a function of ultraviolet intensity by exposing tadpoles to different levels of ultraviolet radiation. From the detailed morphological descriptions a more reliable binomial key was constructed, which made it possible to distinguish between Amietia umbraculata and A. vertebralis. A new amended definition of the epidermal elygium can now be given as an area of melanophores originating from the pigmented epithelium of the retina, forming a hemispherical shape from the dorsal margin of the iris. It is positioned in such a way as to protect the retina when light enters directly from above. This empirical study of the functional significance of the elygium showed that elygium morphology was considerably plastic, and that there were differences in elygium area and base length in the presence or absence of UVB radiation. In the presence of high UV radiation tadpoles produced an elygium with a broader base rather than longer elygia with a larger area. A wider elygium base shaded the pupil more effectively, thus protecting the retina from harmful UV radiation. The presence of a ventral elygium was also discovered. / Thesis (M.Sc. (Environmental Science))--North-West University, Potchefstroom Campus, 2011.

This study resulted from the identification of gaps in the literature pertaining to the morphological descriptions of the tadpoles occurring at high altitudes in the Drakensberg Mountains in South Africa. These tadpoles are exposed to low temperatures, high desiccation risk, elevated ultraviolet radiation, competition, and predation and inhabit the clear, flowing streams and marsh areas of the mountain. Highly varying environmental conditions caused tadpoles to have considerable intraspecific variation. The high degree of plasticity necessitated extensive descriptive studies of tadpole morphology in order to document intraspecific variation and set up reliable keys for species identification. Specified adaptations to the extreme montane conditions are present in tadpoles of certain species. An especially interesting adaptation is the elygium, a hemispherical pigmented area above the eye, which apparently protects the retina from harmful ultraviolet radiation. There are no known studies of elygium plasticity in tadpole eyes in relation to variation in ultraviolet radiation. Particular attention was given to the functionality and cytology of this structure. Detailed measurements of tadpoles of six frog species of the high altitude Drakensberg Mountains were made. Morphological adaptations were described on the basis of these measurements. The cytological origin of the elygium of Amietia vertebralis was revealed through histological and cellular ultrastructure studies. The change in elygium morphology over time was studied as a function of ultraviolet intensity by exposing tadpoles to different levels of ultraviolet radiation. From the detailed morphological descriptions a more reliable binomial key was constructed, which made it possible to distinguish between Amietia umbraculata and A. vertebralis. A new amended definition of the epidermal elygium can now be given as an area of melanophores originating from the pigmented epithelium of the retina, forming a hemispherical shape from the dorsal margin of the iris. It is positioned in such a way as to protect the retina when light enters directly from above. This empirical study of the functional significance of the elygium showed that elygium morphology was considerably plastic, and that there were differences in elygium area and base length in the presence or absence of UVB radiation. In the presence of high UV radiation tadpoles produced an elygium with a broader base rather than longer elygia with a larger area. A wider elygium base shaded the pupil more effectively, thus protecting the retina from harmful UV radiation. The presence of a ventral elygium was also discovered. / Thesis (M.Sc. (Environmental Science))--North-West University, Potchefstroom Campus, 2011.

Thesis (Ph. D.)--Ohio State University, 2005. / Available online via OhioLINK's ETD Center; full text release delayed at author's request until 2008 Nov 30

Made available in DSpace on 2014-08-13T14:50:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-03-15Bitstream added on 2014-08-13T18:01:14Z : No. of bitstreams: 1 000734591_20160315.pdf: 127535 bytes, checksum: a1782b80512836097cf9680fcc2f00c3 (MD5) Bitstreams deleted on 2016-03-15T12:06:56Z: 000734591_20160315.pdf,. Added 1 bitstream(s) on 2016-03-15T12:07:33Z : No. of bitstreams: 1 000734591.pdf: 12563553 bytes, checksum: 66a404ef9ee14c6279d474e173d6f5e5 (MD5) / Estudos sobre a ecologia de comunidades e identificação de padrões de distribuição de anfíbios são de suma importância para conservação de espécies. Foi realizado o inventário da anurofauna da região de Bauru, caracterizando os padrões de distribuição geográfica em âmbito regional e estadual das espécies registradas, bem como foi analisado a ecologia e a plasticidade na ocupação do hábitat destas espécies. A hipótese deste trabalho é que a composição e a estrutura da comunidade de anfíbios da região apresentam características próprias, associadas às variáveis ambientais e aos aspectos físico-estruturais, diferindo de outras comunidades, inclusive de regiões próximas. O estudo foi desenvolvido entre 2009 e 2012. Foram registradas 37 espécies, as quais representam 15,61 % dos anfíbios do Estado de São Paulo. Dentre as espécies registradas, uma é endêmica do estado, Scinax hiemalis. As espécies com maior abundância no estudo foram Dendropsophus minutus, D. nanus, Hypsiboas albopunctatus, H. caingua, Scinax fuscomarginatus, S. fuscovarius, Physalaemus cuvieri e Leptodactylus podicipinus, que representam 72,2% do total de indivíduos registrados. O pico de atividade de vocalização dos anuros ficou concentrado durante a estação chuvosa. Entre os ambientes ocupados pelos anuros, durante o período reprodutivo, na região, apenas quatro espécies foram exclusivas de corpos d’água no interior de mata: H. lundii, S. hiemalis, C. caramaschii e L. mystaceus. As demais ficaram divididas entre aquelas que utilizaram exclusivamente, corpos d’água em área aberta (44,5%) e espécies que utilizaram corpos d’água tanto no interior de mata como em área aberta (44,5%). Houve um predomínio de espécies que apresentam distribuição na região centro-oeste do estado, com 16 espécies. Doze espécies possuem ocorrência em todo estado, oito apresentam ocorrência na região centro-leste e apenas ... / Studies about the ecology of communities and identification of amphibians distribution patterns are extremely important for species conservation. Was realized an anurofauna inventory in the region of Bauru, characterizing the geographic distribution patterns at the regional and state levels of the recorded species, as well as discussed the ecology and habitat occupation and plasticity on these species. The hypothesis is that the composition and amphibians community structure on that region has specific characteristics, associated with environmental variables and physical-structural aspects, differing from other communities, including nearby regions. The study was conducted between 2009 and 2012. Were recorded 37 species, which represent 15.61% of the amphibians at São Paulo state. Among the species reported, one is state endemic, Scinax hiemalis. The species with the highest abundance in the study were Dendropsophus minutus, D. nanus, Hypsiboas albopunctatus, H. caingua, Scinax fuscomarginatus, S. fuscovarius, and Leptodactylus podicipinus Physalaemus cuvieri, representing 72.2% of all individuals recorded. The peak in of anurans activity calling was concentrated during the rainy season. Between the occupied environments by anurans during the reproductive period in the region, only four species were exclusive of water bodies inside the forest: H. lundii, S. hiemalis, C. caramaschii and L. mystaceus. The others were divided into those who used exclusively water bodies in open area ...

Made available in DSpace on 2016-05-17T16:51:53Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-11-30. Added 1 bitstream(s) on 2016-05-17T16:55:50Z : No. of bitstreams: 1 000863115.pdf: 1460438 bytes, checksum: e83408ca558426e55907a44e2bbcee1b (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Entre os diferentes ambientes da Mata Atlântica as áreas de maior altitude são o hábitat de algumas espécies endêmicas de anfíbios anuros. Tais espécies podem fornecer evidências para testar a hipótese de que os ambientes montanhosos e acidentados propiciam barreiras à dispersão, fazendo com que cada população, passando por processos independentes de evolução, sofra especiação. Ischnocnema holti encontra-se em áreas de altitude da Mata Atlântica e trabalhos anteriores revelaram que há divergência genética entre os espécimes de diferentes localidades, havendo confusão de identificação com Ischnocnema lactea. Os objetivos deste estudo foram caracterizar geograficamente a diversidade genética de I. holti; discutir a existência de possíveis novas espécies neste complexo e inferir os processos históricos envolvidos em sua diversificação. Para inferir as relações filogenéticas, utilizamos dados de sequências de dois genes de DNA mitocondrial e quatro genes nucleares juntamente com Inferência Bayesiana e Máxima Verossimilhança. Estimamos tempos de divergência (TMRCA) e também utilizamos a análise de agrupamento Bayesiano. Finalmente, nós modelamos o complexo sob condições atuais e passadas. Os resultados deste trabalho indicam que as populações de I. holti e I. lactea formam um complexo de espécies distribuídas nos topos das montanhas da Mata Atlântica do Sudeste do Brasil. Nós encontramos seis clados bem suportados pelos marcadores mitocondriais e nucleares (ainda que com pequenas variações) e geneticamente bem divergentes, porém não foi possível resolver a relação entre os mesmos. As modelagens sugerem que as populações deste complexo permaneceram restritas as regiões de altitude pelo menos desde o Último Interglacial (120 mil anos atrás), ainda que possam ter tido uma pequena expansão de habitat no último Máximo Glacial. A datação da... / Among the different environments of the Atlantic forest, the high altitude areas are habitat for some endemic species of amphibians. Such species can provide evidence to test the hypothesis that mountainous environments provide barriers to the dispersion. Thus, each population can evolve independently, suffering speciation. Ischnocnema holti is found in high altitude areas of the Atlantic forest. Previous papers have shown that there is genetic divergence between samples from different locations and that there is misidentification with Ischnocnema lactea. The aims of this study were to characterize geographically the genetic diversity of Ischnocnema holti, to discuss the existence of possible new species in this complex, and to infer the historical processes involved in the diversification of Ischnocnema holti. We infer phylogenetic relationships using DNA sequence data from two mitochondrial and four nuclear genes coupled with Bayesian and Maximum Likelihood reconstructions.We estimated divergence times (tMRCA) and also used Bayesian clustering analysis. Finally, we modelled the location of suitable climate for the complex species under present-day conditions and paleoclimates (SDMs). These results indicate that populations of I. holti and I. lactea form a complex of species distributed in the tops of the mountains of the Atlantic Forest of southeastern Brazil. We found six clades supported by mitochondrial and nuclear markers (even with minor variations) and genetically divergent, however we could not resolve the relationship between them. The modeling suggests that the populations of this complex remained restricted regions of altitude at least since the Last Interglacial (LIG), although they may have had a small habitat expansion in the last Glacial Maximum. The dating of the separation of lineages also suggests an older isolation, and the separation would have occurred between 7 and 11 million years... / FAPESP: 2013/22702-7

Orientador: Célio Fernando Baptista Haddad / Banca: Rogério Pereira Bastos / Banca: Anne Taffin D'Heursell Baldisseri / Banca: Ricardo Jannini Sawaya / Banca: Itamar Alves Martins / Resumo: Até a presente tese, a informação sobre predação e estratégias defensivas em anuros estava fragmentada e desconexa na literatura científica. Na ausência de uma revisão sobre o tema, algumas especulações foram geradas baseadas nas impressões pessoais de diversos pesquisadores. Por exemplo, existem muitos ou poucos relatos de anuros sendo apresados? Um determinado comportamento defensivo já foi descrito em algum lugar, ou é inédito? Qual a relação entre os predadores e os mecanismos de defesa dos anuros? Essas e outras perguntas estavam em aberto. Mesmo em livros texto, os quais geralmente revisam os assuntos abordados de forma abrangente, nota-se o parco conhecimento sobre o tema, sendo estes sempre os menores capítulos dos livros e de conteúdo razoavelmente superficial. Todavia, muita informação já foi gerada e muita ainda está por vir. É nesse sentido que idealizamos e realizamos o presente estudo, visando reunir grande parte do conhecimento atual e gerar novas previsões e hipóteses testáveis. Assim, relacionamos os predadores atuais e naturais dos anfíbios anuros (incluindo as desovas e pós-metamórficos) e revisamos as principais estratégias defensivas dos adultos (pós-metamórficos). Muitos dados apresentados são inéditos e outros compilados da literatura, mas ambos analisados de maneira integrada e sempre dando enfoque evolutivo nas discussões apresentadas. Consideramos este estudo um ponto inicial para compreendermos mais profundamente as estratégias defensivas dos anuros e sua relação com os predadores naturais. / Abstract: Until the present moment, the information about defensive strategies and predation upon anurans was fragmented and disconnected in the scientific literature. In the absence of an overview of the subject, some speculations have been raised based on personal points of view of several scientists. For example, are there many or few reports of predation upon anurans? A specific defensive behavior has already been described or not? How is the relationship between the defensive strategies and predator mechanisms? These and odder questions were hard to answer. Even in text books, where the subjects are treated in a broad way we can notice the poor knowledge of the subject and these are always the shorter and superficial chapters. However, many information is already available and many is about to come. Therefore, we idealized and did the present thesis, aiming to joint a large part of the current knowledge and promoting some previsions and testable hypotheses. So, we related the actual and natural predators of anurans (including eggs and post-metamorphics) and reviewed the main defensive strategies of the adults (post-metamorphics). A great amount of the data presented is novel and other set of data were found in the available literature, but both were analyzed simultaneously with an evolutive approach. We consider this thesis a starting point of a deeper comprehension of the anurans’ defensive strategies and their relationship with natural predators. / Doutor

Amphibians are the most threatened of all vertebrates. Alarming declines of amphibian species is considered to be a direct consequence of extreme vulnerability associated with specific requirements of the micro - environmental conditions. Disruption of these conditions causes irreversible changes in species composition of amphibians, affected area tends to have lower diversity and abundance of native species. The most threatened amphibian species are those with narrow habitat preferences, living in specific areas where any intervention can lead to rapid decrease or complete disappearance of species. Habitat loss, intensive land use, fragmentation, invasive species, diseases, pesticides and climate change are the main causes of dramatic decline in amphibian species richness worldwide. Habitat loss, endangering many species worldwide, is considered the biggest threat to amphibians. Southeast Asia is currently experiencing one of the largest global deforestations. Many factors are involved in forest losses, e.g. Population growth, logging, changes in cultivation practices, infrastructure growth, politics, forest fires and global environmental factors. At least half of the forest loss is associated with human activity. Deforestation due to agriculture or livestock expansion causes degradation and loss of soil, microclimate changes and loss of biodiversity. An extent reduction in space required for preservation and development of biodiversity is the result of devastation of the environment. This process particularly affects the presence and abundance of native amphibian species. It has been proven that even low to moderate levels of anthropogenic disturbance have a measurable and profound impact on tropical species. Examples are conversion of rainforests to oil palm monoculture plantations, destroying the entire ecological niche, disrupting complex food chains and natural migration corridors of animals. Compare to forests or other woody crops plantations, significantly fewer species are found in areas with oil palm. The main aim of the practical part of this thesis is a field research carried out in two different island areas in Indonesia. The research was primarily focused on frog species composition in different habitats. Selected target areas were the islands of Simeulue and Bangkaru that are a part of a chain of islands on the west coast of Sumatra. These research areas were chosen for various types of biomes represented on them. Biotope of the first of the islands was largely affected by human activity hence a significant part of it is used for agriculture. The second island was never affected by human activity and is entirely covered with primary rainforest. On the base of research performed in farm area of the island of Simeulue, following frog species were confirmed to occure: Duttaphrynus melanostictus (Schneider, 1799), Odorrana hosii (Boulenger, 1891), Limnonectes macrodon (Duméril a Bibron, 1841) and Amnirana nicobariensis (Stoliczka, 1870). Presence of two frog species not described on Simeulue yet was proven - Microhyla fissipes Boulenger, 1884 and Rhacophorus margaritifer (Schlegel, 1837). Presence of Hylarana parvacola (Inger, Stuart & Iskandar, 2009) was confirmed on the island of Bangkaru. Furthermore one, on Bangkaru previously undescribed species, Limnonectes macrodon (Duméril a Bibron, 1841) was discovered. Richer frog species diversity was found in economically utilized areas on inhabited island of Simeulue. Frog diversity in the primary forest on Bangkaru, which has never been colonized, was lower. The results may collide with literature, indicating that a greater diversity of species is occurring in less disturbed areas. This proves that the abundance of species can be influenced not only by environment disturbance but also by other factors. In this case, different sizes and levels of isolation of the islands are probably involved. These findings are supported by the theory of island biogeography, which states that large islands have more species than small ones and islands close to the mainland have more species than isolated ones. The objective of this work was only a basic research; its findings should be supported by more detailed studies carried out in the area.

Orientadora: Profª. Drª. Vanessa Kruth Verdade / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Evolução e Diversidade, 2016. / Pertencentes à família Cycloramphidae, Cycloramphus e Zachaenus são gêneros de estreita afinidade. Restritos a Mata Atlântica brasileira estão presentes em áreas de relevo acidentado, ocupando riachos com corredeira, serapilheira em áreas florestadas ou campos rupestres. Com base no tipo de larvas podem ser divididos em dois grupos: um que apresenta larvas exotróficas que se desenvolvem sobre rochas úmidas e inclui 19 espécies, e, outro, com 11 espécies, em que as larvas são endotróficas e desenvolvem-se em ambiente terrestre, sob rochas ou troncos caídos. Externamente os adultos podem ser diagnosticados pela presença de menisco na parte superior da íris e tímpanos não visíveis, mas a interpretação dada por diferentes autores a outras características de sua anatomia faz com que existam questões taxonômicas ainda pendentes no grupo, que só poderão ser respondidas através de hipóteses filogenéticas. Este trabalho testou a relação filogenética das espécies dos gêneros Cycloramphus e Zachaenus baseadas na análise comparativa de caracteres de morfologia externa e condrocrânio de seus girinos, associada a técnicas de pesagem diferencial. O resultado obtido corrobora o monofiletismo de Cycloramphidae e sugere a subdivisão da família em dois clados. Um deles que inclui as espécies de Cycloramphus e Zachaenus cujos girinos são endotróficos. Outro, que inclui as espécies de Cycloramphus com larvas exotróficas e Thoropa. O aninhamento de Zachaenus entre as espécies de Cycloramphus já foi sinalizado por estudos anteriores, mas o agrupamento de Thoropa aos demais Cycloramphus é inédito. A configuração sugere a necessidade de modificações na taxonomia, já que Cycloramphus não seria monofilético. Um dos arranjos possíveis seria a manutenção de Thoropa, restrição de Cycloramphus às espécies de Cycloramphus que apresentam girinos exotróficos, e transferência das espécies atualmente em Cycloramphus que apresentam girinos endotróficos para Zachaenus. Entretanto, em se tratando de caracteres larvais, seria conveniente testar a existência de sinal filogenético com caracteres de outras fontes e amostras maiores, incluindo larvas de outras espécies do gênero Thoropa e de grupos externos considerados mais próximos à Cycloramphidae do que aqueles utilizados. A principal consideração a ser feita diante do arranjo obtido, é se a altíssima especialização das larvas das espécies em Cycloramphidae não estaria introduzindo ruído gerando uma hipótese de relacionamento que reflete mais a ecologia do que a história evolutiva do grupo. / Cycloramphus and Zachaenus (family Cycloramphidae) are considered close related. The species in these genera are stream or ground dwellers frogs endemic to areas of sharp relief at the Atlantic forest Domain. If based on larvae morphotype, the species may be split in two groups: 19 species which tadpoles are exotrophic and semiterrestrial living on humid rocks, and 11 species which tadpoles are endotrophic and terrestrial living under rocks or fallen trunks. The adults are relatively similar, and promptly identified by the presence of an eye meniscus and hidden tympanum. However, the presence of inguinal macrogland in adult males and terrestrial reproduction has led to different interpretation and different taxonomic arrangements involving Cycloramphus, Zachaenus, and a third genus Craspedoglossa, currently under synonym of Cycloramphus. These arrangements can be tested only under phylogenetic hypothesis. We have used comparative anatomy of larvae to set 40 characters from external morphology and chondrocranium and obtain a phylogenetic hypothesis for the groups of species. Our results are congruent to the monophyly of Cycloramphidae family and suggest two clades within it: one including the Cycloramphus and Zachaenus species presenting endotrophic and terrestrial tadpoles; the other including Thoropa and the Cycloramphus presenting exotrophic semiterrestrial tadpoles. Zachaenus nested within Cycloramphus is a combination that has already raised in literature, however Thoropa as the sister group to the Cycloramphus species with exotrophic tadpoles is a novelty. This arrangement makes Cycloramphus a non monophyletic genus and requires taxonomic changes. Cycloramphus should be restricted to the species which tadpoles are exotrophic, and Zachaenus expanded to include also the Cycloramphus which tadpoles are endotrophic. We think these changes premature, though. Considering larval characters, and the very high specialization of Cycloramphidae larvae, it may be possible that the arrangement obtained is more a reflex of ecological similarity than evolution history. The taxonomic changes should be postponed until we could test the phylogenetic signal of these characters by using more than one species of Thoropa; outgroup species closer related to Cycloramphidae, as well as characters from different sources as internal oral anatomy from larvae, morphology of adults, and molecular markers.