Chinese Bullfrog

Description: A very large frog, second in size only to Rana spinosa, up to 12.5 cm or more in length. Olive-brown in colour, with scattered, black spots. Dorsum with many elongated wrinkles. Lips ornamented with broad, black bars. Is like an enlarged version of R. limnocharis, but can easily be distinguished from the latter by the much larger size, stocky body build, strongly tapering snout and the large eyes, which are set very close together dorsally. Flanks spotted, resembling leopard skin. A skin fold extends from behind each eye to the shoulder. Underside white. Throat with dark mottling.

Habits and habitat: Its habitat is almost identical with that of R. limnocharis, but this large species requires deeper water, and is much less common for several reasons: (1) habitat destruction (this species may be more dependent on rice paddies than R. limnocharis); (2) is relished as a food delicacy locally; (3) the widespread use of insecticide in modern farming methods. Primarily a lowland species, but has been seen in paddy areas at higher elevations, up to about 450 m.

Diet: Feeds mostly on large insects, but also on small rodents and small frogs. The gut contents of some specimens were found to contain partially digested mice.

Reproduction: Breeding season commences in early spring. Tadpoles brownish and large, 5 cm or more in total length. Young frogs about 2.5 cm at metamorphosis.

Distribution: Present, but uncommon, throughout the New Territories and the larger islands. Widespread in central and southern China including Taiwan, Burma and Thailand. It is uncertain where in Asia the range of this species meets that of the similar Rana tigerina - an Indian species. R. rugulosa is the common edible frog sold at local markets, but the animals are imported from China and Thailand.

Diagnostic features: Skin wrinkled; with large, irregularly scattered black spots; tapering snout; lips with broad, black bars; checkered spotting on the flanks.