Giant Spiny Frog

Description: A very large frog, the giant among Hong Kong frogs, up to 14 cm or more in length from snout to vent. Dark brown in colour, interspersed with dense, yellowish mottling. Skin weakly wrinkled dorsally. A distinct fold of skin extends from the eyes to the fore limbs. Differs from the sympatric Rana exilispinosa in its much larger size, fully webbed hind feet - the webbing extends to the tips of the toes - and hidden tympanum. Underside white.

Habits and habitat: The adults were first recorded in Hong Kong in 1978. Seems to be restricted to higher altitudes. Occurs in strams on Tai Mo shan at 600 m or above. Strictly nocturnal and predominantly aquatic. The streams which it inhabits are boulder-strewn and precipitous. Occurs both in swiftly flowing torrents and quiet pools. May be found sitting on rocky ledges below waterfalls and on rocks within the pools.

Diet: Feeding habits not specifically known, but remains of fresh water crabs and large beetles were found among the stomach contents.

Reproduction: Breeding habits not well known. Males develop black horny spines on the chest and fingers during the breeding season in spring and summer. Eggs, as reported by C. H. Pope, are laid under stone in streams. Tadpoles dark brown or greyish, very large, 6-7 cm in total length, and usually with bands on the tail. Young froglets about 3 cm long at metamorphosis.

Distribution: In Hong Kong is only found on Tai Mo Shan. Widely distributed in central and southern China, also in Vietnam.

Diagnostic features: Very large size at maturity; skin mottled yellow; tympanum not visible externally; fully webbed hind feet.