Biologia reprodutiva e alimentar de Bothrops atrox (serpentes, viperidae) nas regiões central e sudoeste da Amazônia

Abstract

The pit viper Bothrops atrox is a widely distributed and locally abundant snake in Amazonia. Given that the reproductive and feeding biology of snakes varies geographically, we aimed to characterize the natural history of individuals from the central and southwestern portions of the biome. For this, we analyzed museum-preserved specimens collected in the region between the metropolitan areas of the Brazilian cities of Manaus and Porto Velho. We took morphometric measurements and performed the analysis of gonads and digestive tracts of 109 individuals. Females attain sexual maturity with larger body sizes. Adults of the species show a pronounced sexual dimorphism in body size being females, on average, larger. The reproductive cycle seems to be synchronized with regional rainfall, which differs from that found in other portions of the biome. The species has a generalist diet with the consumption of a wide range of prey such as centipedes, frogs, lizards, snakes and mammals. This study first recorded the predation of the snake Imantodes cenchoa (Dipsadidae) by B. atrox. There is an ontogenetic shift in the diet: smaller individuals feed mainly on ectothermic prey (centipedes, frogs, lizards and snakes), and adults tend to incorporate endothermic items (mammals) to their food repertoire.