Testes asymmetry of <em>Bufo gargarizans</em> in relation to body condition and age

Abstract

Testes asymmetry theory predicts that males in good condition or mature age may be able to develop larger degrees of directional asymmetry than males in poor condition or younger age. In this study, we tested the testes asymmetry theory in the Bufo gargarizans. We found that B. gargarizans has a significant directional asymmetry in testes mass, with left testis being significantly larger than right testis. Male body condition was correlated with relative testes mass and absolute testes asymmetry, but not correlated with relative testes asymmetry. Therefore, we suggested that males in good body condition have the higher ability of sperm competition than males in poor body condition. Additionally, male age was correlated with absolute testes asymmetry, but not correlated with relative testes mass and testes asymmetry, thus not supporting the hypothesis that males with a higher degree of directional asymmetry survive better.