Uperoleia crassa

Conservation Status

Calling Period

Description

A small species of frog reaching up to 3 cm in body length. It has a red-brown, dark-brown, or light grey-brown back. There are darker brown patches, and a thin, orange longitudinal line along the middle of the back if the back is light grey-brown. The lower half of the sides of the body and head are often grey, and the arms and legs sometimes have horizontal bars. There is sometimes a small, pale pink, pale brown-yellow, or white stripe from the edge of the mouth to the arm. The belly is pale pink with white specks or grey-white. The male has a grey throat. The groin and the backs of the thighs are bright red. The pupil is horizontal, and the iris is gold or silver-gold. Fingers are unwebbed without discs, and toes are either unwebbed or half-webbed, also without discs. The parotoid glands are large and red-brown, orange, pale orange-brown, or pale yellow-brown. Due to variation in advertisement calls, Uperoleia crassa was previously considered to be two species: Uperoleia crassa restricted to the Kimberleys, and Uperoleia inundata from the Top End, and the western part of the Kimberleys. However, recent research led by Australian Museum Research Associate Dr Renee Catullo has revealed these to be a single species: Uperoleia crassa. The differences between the advertisement calls are thought to have arisen where the distribution of Uperoleia crassa overlaps with the related Uperoleia borealis.

Breeding Biology

Eggs are laid singly and attached to vegetation under the surface of the water in temporary ponds, drainage lines, swamps, and creek pools. Tadpoles can reach a total length of up to 4 cm, and are brown to gold-brown in colour. They often remain at the bottom of water bodies, and take around two months to develop into frogs. Breeds during summer in the wet season.

Similar Species

Looks very similar in its distribution to: Uperoleia lithmoda, which has smaller glands and a different call; to Uperoleia borealis, which is also smaller with a different call; and to Uperoleia arenicola, Uperoleia minima, and Uperoleia micra, all of which again have different calls. The best way to differentiate it from Uperoleia daviesae is by call or DNA.