Portal de Periódicos da CAPES

Artigo Acesso aberto Produção Nacional

BIBTEX RIS

Estrutura populacional, tamanho e razão sexual de Podocnemis unifilis (Testudines, Podocnemididae) no rio Guaporé (RO), norte do Brasil

2004; UNIVERSIDADE DE SÃO PAULO; Volume: 3; Issue: 1 Linguagem: Inglês

10.11606/issn.2316-9079.v3i1p29-42

2316-9079

Augusto Fachín Terán, Richard C. Vogt,

Fish Biology and Ecology Studies

Population structure and sex ratio of Podocnemis unifilis was studied from June to November 1989 and from March to June 1990 in the Guaporé river and its tributaries São Domingos and São Miguel, in the municipality of Costa Marques, Rondônia, Brazil. The margins of these rivers are not altered much by human activities and the water is not polluted in any way. Turtles were captured using 12 fyke nets. Around 1 % of the captured turtles died using this method. The majority of the turtles was captured in the bays and oxbows (55.8%) and when the water level of the river was declining (N=785). The proportion of adults (73.4 %) in the sample was about three times higher than that of juveniles (26.6 %). The distribution of carapace length in males formed a normal curve, while that of females showed no well-defined pattern. The sex ratio of adults in this population was 9.8 males per female.