Lepidochelys olivacea (Eschscholtz, 1829)

Pacific Ridley Turtle

Pacific Ridley Turtle
Adult, Photo: P. Ross/WWF. Inset: hatchling, Photo: P.C.H. Pritchard/WWF.

Description: A smaller sea turtle than most, growing to about 75 cm in carapace length. Carapace heart-shaped, rather flat, dark grey in colour. Five to nine costal shields. Head rather small and narrow. All limbs modified as flippers, each with only one claw. Carapace of juveniles with a single median keel and the margin at posterior end slightly dentate.

Habits and habitat: Very little is known about the habits of this turtle as it is not a nesting species in Hong Kong, but is occasionally sighted in local waters.

Diet: Its feeding habits are little known, but remains of crab parts have been found in its faeces.

Reproduction: Does not breed in Asia, but in Costa Rica, where it arrives in huge numbers to lay egg on sandy beaches. The eggs take 2 months or more to hatch.

Distribution: Has been recorded with certainty only four times in Hong Kong: a dead specimen was found on the beach of Stonecutters Island in 1973; a live specimen was reported in the sea off Sau Kei Wan in 1978; a shell belonging to this species was found washed ashore on a south-western beach on Lamma Island, and a freshly dead adult was found at Shek O in 1996. Its range along the Chinese coast stretches from the South China Sea to the East China Sea. Elsewhere is found in the Pacific, Indian and South Atlantic Oceans.

Diagnostic features: Carapace heart-shaped, flat, dark-grey; up to nine costal shields; four enlarged inframarginals each with a pore at posterior edge; paddle-like flippers; one claw on each limb. 1