Auto-ecologia de Hypsiboas albopunctatus Spix 1824 (Anura: Hylidae)em ambiente de cerrado no sudeste do brasil

Abstract

The Hypsiboas albopunctatus group was recently defíned based on molecular data and derivations are not recognized supporting its monofiletic nature. In the present study we described qualitative and quantitatively aspects of the autecology of H albopunctatus. The observations were taken in Uberlândia - Brazil. The visits to the field were weekly among January from 2002 to March of 2005. Behavioral events were accompanied focally. We described the sexual dimorphism, number of eggs for spawning, spawning place and coloration of the tadpoles. We also sought for eventual differences in the abundance of tadpoles in lakes (potentially predatory Teleostei present) and puddle (these predators absent). To describe the variation in depth, amount of vegetable substratum and number of arthropods between the two habitats and its relationship with the abundance of tadpoles, we used an Principal Component Analysis. We tested the palatability of eggs and tadpoles for two species of Teleostei. We determined the pattem of activity, of use of micro-habitats and the spatial distribution of the tadpoles. The males vocalized in all of the months of the year (except July), they were smaller than the females, possessed spines in the prepolexes and a distended vocal sac. The amplex was alternated between the timpanic and cephalic types. The eggs (mean 769) were laid flotating only single layer amidst vegetation. The tadpoles coloration change from black to tan. The eggs were not consumed by the two tested species of Teleostei, however the tadpoles were. The tadpoles were active during the night and were clumped distributed at puddles and lakes. The puddles presented larger number and mass of tadpoles and number of arthropods. In the global sample, the density of tadpoles was correlated with that of arthropods, but not with vegetable substratum and nor with the depth. The almost continuous reproductive activity among H. albopunctatus is a rare event among frogs of southeast of Brazil. We didn't observe physical combats among males in spite of they present a spines in the prepolexes. As in most of the frogs, the females were larger than the males. The tympanic amplexus can avoid that the male hurts the female during the preparation of the place for the ovoposition. The eggs seem to be impalatable for the Teleostei tested. The tadpoles were more abundant in the puddles, where the pressure of predators may be smaller.