Dinâmica dos girinos e caracterização da larva do anuro endêmico Hylodes fredi (ANURA: HYLODIDAE) na Mata Atlântica da Ilha Grande, Rio de Janeiro

• Ano de defesa: 2010
• Autor(a) principal: Laia, Rafael Camilo
• Orientador(a): Rocha, Carlos Frederico Duarte da
• Banca de defesa: Sluys, Monique Van, Tavares, Henrique Wogel
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade do Estado do Rio de Janeiro
• Programa de Pós-Graduação: Programa de Pós-Graduação em Ecologia e Evolução
• Departamento: Centro Biomédico::Instituto de Biologia Roberto Alcantara Gomes
• País: BR
• Palavras-chave em Português: Girino; Anuro; Anfíbio; Ilha Grande
• Palavras-chave em Inglês: Amphibia; Anura; Density; Energetic condition; Environmental factors; Hylodes fredi; Ilha Grande; Morphological description; Population ecology; Tadpoles
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::ECOLOGIA
• Link de acesso: http://www.bdtd.uerj.br/handle/1/5788

Hylodes fredi is an endemic frog from Ilha Grande, an Atlantic Forest island, located in Rio de Janeiro state, southeast Brazil. The tadpoles of this species are found in clear stream backwaters in the forest, rocky substrate, in shallow waters where calling male frogs can be found. In order to improve the population dynamic knowledge of H. fredi larval stage, we compared their occurrence, density and energetic condition in four streams from the south portion of Ilha Grande in twelve months, relating them to the physicochemical parameters of the water. Energetic condition was calculated as residual of the relationship between the natural logarithm of mass and the natural logarithm of body length of all the H. fredi tadpoles sampled. Density and condition of the H. fredi larvaes varied between the streams. All variables of water measured (dissolved oxygen, conductivity, temperature and depth), except for pH, influenced the discrimination between the streams. The occurrence of tadpoles with different sizes and masses in all the months, without a clear seasonal variation, suggests that H. fredi has an extensive reproductive period along the year. Both environmental factors of the water and H. fredi tadpoles densities were different between the same streams. However, the energetic condition of the larvaes and the abiotic factors did not differentiated between the same streams. The differences found in density and energetic condition of H. fredi tadpoles between dry and wet seasons indicate that environmental conditions are more appropriate in the wet season, with greater availability of resources. Hylodes fredi larvaes living in streams with higher densities of Hylodidae tadpoles (H. fredi and Crossodactylus gaudichaudii) have smaller energetic condition values. This result seems to be probably due to the sharing of the limited resources, once these would be scarcer for each individual. Density of H. fredi tadpoles was more influenced by the physicochemical factors of the environment, while energetic condition of these tadpoles was more influenced by the biological factors of the environment. Then, density and energetic condition of H. fredi tadpoles vary in result of a balance between the abiotic and biotic parameters of the streams in which the larvaes occur. In this study, we also describe the tadpole of H. fredi.