Males are distinguishable from females due to hard swellings (called nuptial pads) on their first finger.

At breeding time, the male gets nuptial pads on the first three fingers.

There is little sexual dimorphism, but the male in breeding season bears a dark, swollen nuptial pad on each thumb.

Males of this species develop nuptial pads on their thumb bases during the breeding season.

Explosive breeders also show a further adaptation to male competition - the development of enlarged nuptial pads on their hands.

When a female joins the male in the water, the male grips onto the female's back, using his nuptial pads, that appear during breeding season.

It contains the tarsal fold and has white velvety nuptial pads on the first fingers.

They have acute hearing but no vocal sac, and also lack nuptial pads.

Roughened nuptial pads on the male's hands aid in retaining grip.

Breeding males have dark nuptial pads on their thumbs.