pdf 03. Sexually dimorphic growth and maturity in captive mountain chicken frogs Leptodactylus fallax

ABSTRACT - Sexual dimorphism is commonly encountered in amphibians. Its presence and its ontogeny in a given species has implications for ecology, conservation and captive husbandry. We monitored changes in length and mass of captive mountain chicken frogs Leptodactylus fallax. Initially, sexes were no different in snout-vent length or mass, but by about 17 months after metamorphosis females became significantly larger and heavier than males. Diverging growth trajectories between male and female frogs appeared to coincide with the development of secondary sexual characters in males, indicating sexual maturity, while female frogs did not produce nests until the following breeding season, suggesting later reproductive maturity. The absence of similar dimorphism in other large leptodactylids suggests that its presence in L. fallax may be linked to its unique and energy-intense reproductive strategy, which involves extended maternal provisioning of their young.