Dimorfismo sexual em Amazophrynella manaos (Anura: Bufonidae)

Abstract

Sexual Dimorphism (DS) is any difference between sexes of a species, other than those of the organs that are directly involved in reproduction. This dimorphism is related to Darwin's theory of sexual selection, where evolutionary factors influence separately on the sexes of the species. The study of sexual dimorphism in anurans is interesting because there are several types of sexual dimorphism, females being larger than the male in body size in most anurans. In order to identify morphometric differences between males and females of the Amazophrynella manaos species, 16 morphometric measurements were performed in 269 specimens from three locations in the city of Manaus - AM. Sex determination was performed by observing secondary sexual characters, gonads in females and vocal sacs in males. For the statistical analyzes, basic descriptive measures (amplitude of variation, mean and standard deviation), analysis of variance (ANOVA) and linear regression were used. After the statistical analyzes of the morphometric data, all means indicated that there is a clear distinction between males and females of A. manaos and that in all measurements females grow more than males.