Orientador: Cynthia Peralta de Almeida Prado / Banca: Cinthia Aguirre Brasileiro / Banca: Denise de Cerqueira R. Feres / Resumo: O gênero Physalaemus inclui 42 espécies distribuídas do norte da Argentina às Guianas. Uma característica interessante do gênero é a capacidade de ocupar uma ampla variedade de ambientes, desde a serrapilheira de florestas úmidas até ambientes sazonais tais como os encontrados no Cerrado, Chaco e Caatinga. Esta dissertação é apresentada em dois capítulos. No primeiro capítulo, dados sobre a biologia reprodutiva de Physalaemus crombiei, uma espécie endêmica da Mata Atlântica, são apresentados, juntamente com as relações tamanho-fecundidade, investimento reprodutivo da espécie, modos reprodutivos e uma comparação com dados obtidos na literatura para mais 12 espécies do gênero. No segundo capítulo foi verificado se fêmeas de diferentes espécies vivendo em ambientes contrastantes investem diferentemente em reprodução. Estas comparações foram feitas entre fêmeas de quatro espécies de Physalaemus associados a áreas florestadas e quatro espécies de área aberta. Neste contexto, as correlações entre os componentes de história de vida destas espécies foram investigadas, bem como a existência de variação no tamanho dos ovos dentro das desovas. Physalaemus crombiei se reproduz ao longo do ano, com seu pico de reprodução nos meses mais chuvosos. Exibe o modo de reprodução típico para o gênero (modo 11), mas pode exibir modos reprodutivos alternativos (modos 14 e 28), assim como outras espécies do grupo de P. signifer. As espécies do grupo de P. signifer depositam desovas com ovos maiores e em menor número do que as outras espécies do gênero. Esta diferença pode ser explicada não apenas pelo menor tamanho destas espécies, mas também por depositarem desovas terrestres. Na comparação entre espécies de mata e área aberta, o tamanho do corpo da fêmea foi correlacionado com o número de ovócitos em apenas duas dentre as sete espécies analisadas / Abstract: The genus Physalaemus includes 42 species distributed from northern Argentina to the Guyanas. An interesting attribute of the genus is the ability to occupy a wide variety of environments, from the leaf litter of rainforests to seasonal environments, such as those found in the Cerrado, Chaco and Caatinga. This work presents two chapters. In the first chapter, data on the reproductive biology of Physalaemus crombiei, an endemic species of the Atlantic Forest, are presented along with the size-fecundity relationships, reproductive modes, and species reproductive investment (RI). A comparison with data from the literature for other 12 Physalaemus species was also made. In the second chapter, we verified if females of different species living in contrasting environments invested differently in reproduction. These comparisons were made between females of four species of Physalaemus associated with forested areas and four species from open areas. In this context, correlations between species' life history components were investigated, as well as intra-clutch variation in egg size. Physalaemus crombiei reproduces throughout the year with a peak in the rainy months, exhibits the typical mode of reproduction for the genus (mode 11), but also presents alternative reproductive modes (modes 14 and 28), such as other species in the P. signifer group. Females in the P. signifer species group produce larger eggs but fewer in number than other species in the genus. This difference can be explained by the smaller size of these species, but also by the ability to place terrestrial clutches. In the comparison between forest and open area species, female body size correlated with the number of oocytes in only two out of seven species analyzed / Mestre

Temporal features in the vocalizations of animals and insects play an important role in a diverse range of species-specific activities such as mate selection, territoriality, and hunting. The neural mechanisms underlying the response to such stimuli remain largely unknown. Two species of anuran amphibian provide a starting point for the investigation of the neurological response to species-specific advertisement calls. Neurons in the anuran midbrain of Rana pipiens and Hyla regilla exhibit an atypical response when presented with a fixed number of advertisement calls. The general response to these calls is mostly inhibitory; only when the correct number of calls is presented at the correct repetition rate will this inhibition be overcome and the neurons reach a spiking threshold. In addition to rate-dependent call-counting, these neurons are sensitive to missed calls: a pause of sufficient duration—the equivalent of two missed calls—effectively resets a neuron to its initial condition. These neurons thus provide a model system for investigating the neural mechanisms underlying call-counting and interval specificity in audition. We present a minimal computational model in which competition between finely-tuned excitatory and inhibitory synaptic currents, combined with a small propagation delay between the two, broadly explains the three key features observed: rate dependence, call counting, and resetting. While limitations in the available data prevent the determination of a single set of parameters, a detailed analysis indicates that these parameters should fall within a certain range of values. Furthermore, while network effects are counter-indicated by the data, the model suggests that recruitment of neurons plays a necessary role in facilitating the excitatory response of counting neurons—although this hypothesis remains untested. Despite these limitations, the model sheds light on the mechanisms underlying the biophysics of counting, and thus provides insight into the neuroethology of amphibians in general.

No description available.

Predation, density and disease affect behavior, morphology and growth. There is a lack of information on how these changes relate to efficiency of energy transfer in anuran larvae, although previous studies suggest that predation should decrease and competition should increase efficiency. Using a 2 x 2 factorial design, we manipulated predation presence and larval density to test how predation risk and density affect energy efficiency. During the experiment, approximately half of the tadpoles were infected by an unknown disease. Neither predation risk nor density affected assimilation or growth efficiency, despite changes in growth and development. Disease, however, decreased gut length and growth efficiency. This study builds on past work on the effects of predation and density on a larval amphibian, but also introduces disease as another factor. Our study suggests that disease may be at least as important if not more important than predation or density in regards to growth efficiency.

A estivação é caracterizada como um conjunto de alterações fisiológicas e comportamentais relacionadas com a redução do metabolismo e a permanência em micro-habitats específicos durante a fase de estiagem. Na caatinga brasileira foram observadas ao menos três espécies que estivam, sendo duas da família Leiuperidae, Pleurodema diplolistris e Physalaemus albifrons e uma da família Cycloramphidae, Proceratophrys cristiceps. Ainda que encontradas no mesmo micro-habitat durante a estivação, estas três espécies exibiram padrões distintos de alteração do desempenho locomotor entre as duas estações marcantes do ano (seca e chuvosa). Enquanto P. diplolistris reduziu em cerca de 47% a velocidade de seu desempenho locomotor durante a fase de estiagem, as outras duas espécies, P. cristiceps e P. albifrons, reduziram cerca de 87 e 83%, respectivamente. Mais ainda, apenas P. diplolistris exibiu mudança de profundidade ao longo da estiagem. A redução da taxa metabólica aeróbia foi de aproximadamente 50% para as três espécies. A comparação entre as estações marcantes do ano ainda revelou que as três espécies estudadas apresentam diferentes padrões de alteração na concentração de substrato energéticos e na atividade de enzimas representativas do metabolismo energético no fígado e musculatura dos membros posteriores. A manutenção hídrica também foi diferente entre as três espécies, o que indica a ocorrência de estratégias diversas de regulação hídrica / Estivation is defined as a set of physiological and behavioral changes associated to decreased metabolism and permanence in specific microhabitats during the dry season. In the Brazilian Caatinga was observed at least three estivating species: Pleurodema diplolistris and Physalaemus albifrons (Leiuperidae) and Proceratophrys cristiceps (Cycloramphidae). Although found in the same micro-habitat during aestivation, these three species differ in the variation patterns of locomotor performance when compared between the two seasons (dry and rainy season). During the dry phase, speed in P. diplolistris is reduced by about 47% whereas in P. cristiceps and P. albifrons values decrease by 87% and 83%, respectively. Moreover, only P. diplolistris exhibited changes of depth along the drought. The reduction of aerobic metabolic rate was of approximately 50% for the three species. The comparison between seasons also revealed that the three species differ in relation to the variation patterns of the concentration of substrate energy and activity of representative enzymes of energy metabolism in the liver and muscles of the hindlimb. The water maintenance was also different among the three species, indicating the occurrence of several strategies of hidric regulation

As Caatingas formam um domínio morfoclimático exclusivo do Brasil, caracterizado por índices pluviométricos baixos e imprevisíveis, além de temperaturas elevadas. Em certos grupos de anuros, a sobrevivência durante o período de estiagem está associada ao comportamento de estivação, um conjunto de alterações observadas que permitem a sobrevivência em condições áridas. Os sapos Pleurodema diplolistris (Leiuperidae/Anura) são encontrados enterrados na Caatinga na fase de seca e evidências indicam que esses indivíduos apresentam menor atividade durante essa fase, apesar de exibirem certa migração vertical no substrato acompanhando a diminuição da umidade deste. O padrão de alterações nas concentrações de lipídeos e glicogênio em diferentes amostras de tecido corrobora a hipótese de diminuição do metabolismo durante o período de estiagem. No músculo dos membros posteriores, a manutenção dos níveis protéicos próximos aos valores observados em animais ativos coletados durante a fase de chuvas, sugere a preservação da capacidade funcional do tecido mesmo nos meses mais adversos. A capacidade aeróbia esteve reduzida durante a fase seca em comparação a fase de atividade e a capacidade glicolítica anaeróbia manteve-se preservada. Verificou-se também um gradiente de umidade vertical no abrigo, evidenciando uma diminuição da umidade a partir da superfície, ao longo da fase de estiagem, o que poderia corroborar a migração vertical. / Caatinga is a Brazilian semi-arid bioma that is characterized by the dryness and the unpredictable seasonality of rains. In some anurans the survive is associate with aestivation, a set of strategies for survival in arid conditions. Pleurodema diplolistris frogs (Leiuperidae/Anura) are found buried in the Caatinga during the dry time. Evidences indicate that individuals of this group have lower activity during this phase, although some exhibit vertical migration in the substrate following the decrease in the moisture of it. The pattern of changes in concentrations of lipids and glycogen in different samples of tissue supports the hypothesis of a reduction of metabolism during the drought. In the muscle of the hindquarters, the maintenance of protein levels close to those values observed in active animals collected during the rainy season, suggests the preservation of functional capacity of the tissue even in most adverse months. The aerobic capacity was reduced during the drought compared to the period of anaerobic glycolytic activity and the capacity has remained preserved. It was also found a gradient of moisture under the vertical, showing a decrease in moisture from the surface, during the drought, which could corroborate the vertical migration.

Orientador: Célio Fernando Baptista Haddad / Banca: Denise de Cerqueira Rossa Feres / Banca: Cynthia Peralta de Almeida Prado / Banca: José Perez Pombal Junior / Banca: Paulo Christiano de Anchieta Garcia / Resumo: A Mata Atlântica é um dos biomas mais biodiversos e, ao mesmo tempo, mais ameaçados do planeta. Estudos com anuros têm corroborado este padrão de diversidade, demonstrando que há grande variação na composição de espécies, mesmo entre localidades próximas neste bioma. Sob estas condições estudos de comunidades com anuros são de alta relevância e oportunos para investigar os fatores que estruturam as comunidades. Deste modo, foram caracterizadas as espécies de anuros de uma área de Mata Atlântica, detalhando a estrutura da comunidade. Investigou-se a organização sazonal das espécies, o padrão de uso do ambiente e a partilha dos recursos e a similaridade com outras taxocenoses do Sul e Sudeste. Para tanto, foram feitas 25 amostragens no Núcleo Santa Virgínia do Parque Estadual da Serra do Mar. As espécies em atividade vocal e demais evidências de reprodução foram registradas e as vocalizações gravadas. Nas excursões, durando de quatro a oito dias, eram amostrados e registrados os ambientes usados pelos anuros. Foram registradas 50 espécies de anuros sendo a ampla maioria tipicamente associada à Mata Atlântica. Na atividade sazonal ocorreu uma gradação entre espécies restritas aos meses do verão, passando por espécies com período mais amplo de atividade, até espécies restritas ao inverno. O padrão de uso do ambiente em geral refletiu a filogenia e a maior sobreposição nesta dimensão do nicho ocorreu entre espécies aparentadas, apesar de também ocorrerem convergências entre espécies pouco aparentadas. Restrições herdadas são mais razoáveis para explicar os padrões gerais de uso do ambiente do que competição interespecífica ou predação ocorrendo no presente. A taxocenose de anuros deste estudo se assemelhou àquelas situadas em áreas serranas da Mata Atlântica. A similaridade na composição de espécies entre as localidades está fortemente relacionada às distâncias geográficas entre elas. / Abstract: The Atlantic forest is one the world's most diverse biomes and at the same time on of the most threatened. Studies on frogs are confirming this pattern, showing great variance in species composition, even among close localities in this biome. From this perspective, studies on frog communities are of extreme importance to elucidate the factors structuring these communities. Thus, herein we characterize the frog species from a locality in the Atlantic Forest, providing details on community structure. Seasonal activity of species, pattern of habitat use, resource partitioning, and species composition similarity between regions in the South and Southeast Brazil were investigated. Twenty-five samples were carried out at Núcleo Santa Virgínia, at the Serra do Mar State Park, São Paulo state, southeast Brazil. Calling activity of species, other reproductive evidences, and vocalizations were registered. During the surveys, which lasted from four to eight days, habitats used by the species were sampled and characterized. A total of 50 anuran species was registered; the great majority typical of the Atlantic Forest. Regarding seasonality, we detected a continuum from species with activity during the summer, to species exhibiting a more prolonged season, up to species restricted to the winter. Habitat use, in general, reflected the phylogeny and the greater overlap occurred among close related species, although convergence among distant species was also observed. Restrictions related to phylogeny are more plausible to explain the general pattern of habitat use observed here, than are present interspecific competition or predation. Community composition at the study site was more similar to those from montane areas located in the Atlantic Forest and species composition similarity was strongly related to the geographic distances among them. Localities under the influence of the Atlantic Forest are less similar among them than are those ... / Doutor

In species where males do not provide immediate benefits to females in the form of resources or parental care to offspring, adaptive mate choice may be maintained by selection because preferred males sire offspring that are genetically superior. I test the hypothesis that female mating preferences result in enhanced performance of their larvae, owing to genetic variation among sires in two species of red-eyed treefrogs. This variation in males may be manifested as body size or in advertisement call parameters. I examined natural pairing patterns and found that both species display a size-based mating pattern with substantial seasonal effects. In lean years, females mate with males that are larger on average, yet females also seem to favor a constant size ratio of the male relative to her body size. I documented significant call trait variation both within and among males and have evidence to support size-related call traits as indicators of mating success for some properties. Finally, I provide evidence for a pronounced effect of sire size on offspring traits, most notably upon hatching that may have significant post-metamorphic fitness benefits. My study provides data on the basis of female choice and may provide a link between female preference for male traits and enhanced offspring performance by larvae sired by preferred males in the evolution of anuran mating systems.

Two Australian frogs were introduced to New Zealand over 100 years ago. Since their introduction they have become widespread and well established with Litoria ewingii being more prevalent in alpine and cooler areas of New Zealand, while Litoria raniformis is found in more temperate coastal areas. Very little physiological data exists for these frogs and aside from their distribution not much is known about them in New Zealand. Thus the effects of thermal acclimation and temperature change on respiration and locomotion were examined in these two exotic frogs. The more terrestrial and alpine dwelling L. ewingii was found to be able to thermally acclimate its respiration performance, where respiration was highest when acclimation temperature matched test temperature. It was also able to thermally acclimate its locomotory performance, jumping significantly further at lower temperatures, however, acclimation to high temperatures impacted its jump performance at cold temperatures. The frog L. raniformis was found to only be able to thermally acclimate its respiration and locomotion to high temperatures, as performance at low temperatures was often poor. The data shows that L. ewingii is a cold temperate frog rather than a warm habitat frog, while L. raniformis is an animal adapted to warm temperatures. From this we can begin to see the effect that temperature has on the physiology of these two exotic frogs and the major role that temperature may be playing in driving the differences seen in the distribution of these two species in New Zealand.

Globally, anurans have experienced significant declines and reliable monitoring protocols are required to track population trends. This thesis compares the effectiveness of manual call surveys (MCS) and automated recording systems (ARS) and describes the calling profiles of seven anuran species in southern Ontario. Using detailed audio recordings, we identify the seasonal and hourly calling patterns of seven anuran species at Warwick and Silver Creek Conservation Areas in the Credit River watershed. We employ descriptive and graphical methods to establish calling profiles. Given the low detection rate of American toads, grey treefrogs and northern leopard frogs, a survey protocol comprised of 9 weekly site visits are recommended in May and June. The optimal time of day for detecting the greatest abundance and species richness is 23h30 whereas optimal survey duration varies with hour and season given the target species. Climatic variables may induce or inhibit call activity and until the extent of these variables can be established, protocol guidelines should implement longer and more frequent site visits. The urgency of this revision is exacerbated for commercial surveys used to make contentious land management decisions.