Answer

Sexual Dimorphism in Frogs: Presence of Copulatory Pads in Males

Male frogs can be identified by a specific anatomical feature known as the copulatory pad, or nuptial pad. This pad is located on the first digit (thumb) of the forelimbs.

Function of the Copulatory Pad

The copulatory pad aids the male frog during mating. When the male mounts the female in a position called amplexus, the pad helps him firmly grip the female to maintain position and alignment for external fertilization. This is especially important in aquatic environments where the frogs’ skin may be slippery.

Hormonal Regulation

The development of copulatory pads is influenced by male sex hormones (androgens) and becomes prominent during the breeding season. Outside this period, the pads may reduce in size or prominence.

Significance

This feature is a useful indicator of sexual dimorphism in frogs and helps in distinguishing males from females, especially in field research and biological studies.