Ocadia sinensis

(Gray, 1834a)
Chinese stripe-necked turtle

The elliptical, slightly depressed carapace (to 24 cm) is slightly serrated posteriorly. Normally all three carapacial keels are lost with age. Vertebral 1 is wider anteriorly than posteriorly; 2-4 are broader than long, or as long as broad. Vertebral 5 is always wider than long. The carapace is reddish brown to black with yellow seams (especially in juveniles), and occasionally some yellow or orange on the projections of the keels. The plastral formula is: abd > pect > fem > gul > an > hum. Plastron, bridge, and undersides of the marginals are cream to yellow with a large dark-brown to black blotch on each scute. The upper jaw lacks a medial notch, and its triturating surface has a well-developed, denticulated medial ridge. The head and neck are olive dorsally and yellow ventrally, and both contain at least eight narrow, dark-bordered, pale-green to yellow stripes. The jaws and chin are cream colored. Limbs are olive with numerous yellow stripes.
The karyotype is 2n = 52; 28 macrochromosomes (18 metacentric or submetacentric, 10 telocentric or subtelocentric) and 24 microchromosomes (Nakamura, 1949; Killebrew, 1977a; Carr and Bickham, 1986). Stock (1972) erroneously reported the karyotype as 2n = 50 (26 macrochromosomes, 24 microchromosomes).
Males have slightly concave plastra and the vent lies beyond the carapacial margin; females have flat to slightly convex plastra with the vent beneath the carapace.

Ocadia sinensis is found in Taiwan, southern China, and westward to at least the Red River watershed of Vietnam.

Geographic Variation
No subspecies are currently recognized, but the newly described O. glyphistoma and O. philippeni may prove to be subspecies of this taxon.

Ocadia sinensis inhabits slow-moving lowland waters with soft bottoms, such as marshes, swamps, ponds, and canals.

Natural History
Smith (1923) reported a captive female laid three eggs in April. The oval, calcareous eggs measured 40 x 25 mm. Hatchling have tricarinate carapaces of about 35 mm, vertebrals wider than long, and long tails.
Ocadia sinensis is herbivorous and will feed on a variety of aquatic plants, as well as lettuce and fruits, in captivity. It is fond of basking and may spend much time in this pursuit.

IUCN Red List Status (1996)
Lower risk: near threatened.