(Gray, 1831b)
Spotted pond turtle
Recognition
Geoclemys hamiltonii is a relatively large (to 39 cm) freshwater turtle with an elongated oval, three-keeled, domed carapace. It is posteriorly serrated, more strongly in juveniles than adults. The keels are interrupted into a series of elevated protuberances, one on each vertebral and pleural. In adults, vertebral 1 is nearly as broad as long, 2-4 are nearly as long as broad, and the 5th is broader than long. Neurals are short sided anteriorly. Ground color of the carapace is black, and there is a series of dorsally pointing orange, yellow, cream, or white wedge-shaped marks at the base of each pleural and spots or radiations of the same color on the vertebrals, giving this turtle a very striking appearance. These light markings fade with age and old adults may be mostly black. The hingeless plastron is yellow with numerous dark radiations. The bridge is extensive with moderate buttresses; axillary buttresses are attached to the 1st costals and inguinal buttresses attach to the sutures between the 5th and 6th costals. The entoplastron lies just anterior to the humero-pectoral seam. The plastron formula is: abd > fem > pect > gul > an > hum, and the anal scutes are deeply notched. In the skull, the frontal bone is excluded from the orbit, and the postorbital is separated from the squamosal by the jugal. The canal of the carotid artery is enclosed within the pterygoid. The upper jaw is broadly notched medially and its triturating surfaces are broad and nearly flat, but McDowell (1964) points out that traces of a cusp-and-ridge pattern, much like that of Morenia, occur clearly on the rhamphotheca and also on the bony surfaces. No medial ridge occurs on the lower triturating surface. Posteriorly, the large black head is covered with small scales, and it has large white or yellow spots on the top, sides, snout, and jaws. The snout barely projects. Neck and limbs are dark brown or black with large yellow spots. The toes are fully webbed; the tail is short.
Males are smaller than females, and have concave plastra and thicker tails. Females have flattened plastra and smaller tails.
Distribution
Geoclemys hamiltonii is a rare species restricted to the Indus and Ganges river drainages of Pakistan, northern India, Nepal, and Bangladesh.
Habitat
Little is known of the ecological requirements of this species, but adults apparently enter large rivers and forest ponds. Pritchard (1979) reported it from oxbow lakes and sloughs in quiet, shallow, rather clear waters with considerable aquatic vegetation.
Natural History
Das (1991, 1995) reported nestings occur from May to October. Two clutches consisting of 26-36 elongated to oval (41-45 x 25-37 mm) eggs are laid each year, typically during the monsoon season (Das, 1991). In captivity, a female laid clutches of 11, 22 and 9 eggs (on 1 May, 1 June and 25 July); six young emerged from the first nest after 74 days (Rotmans and Rotmans-Zwaal, 1994). Hatchlings are three-keeled and more brightly patterned (with numerous white spots) than are adults; they are about 35-37 mm long.
Geoclemys is almost entirely carnivorous, feeding on snails and other invertebrates, and probably also fishes and amphibian larvae, but it also consumes algae.
IUCN Red List Status (1996)
Lower risk: near threatened.