(Geoffroy St.-Hilaire, 1809)
Malayan softshell turtle
Recognition
The oval, very flat carapace (to 26 cm) is black to olive or dark brown with a black medial stripe and two or three pairs of black-centered, slightly yellow-bordered ocelli. This pattern fades with age. There are several longitudinal rows of small tubercles on the carapace; the anterior rim lacks tubercles. A single neural occurs between the 1st pair of costals. The 8th pair of costals is well-developed but, like the preceding seven pairs, separated by a neural bone. Costals and neurals are roughened with granulated rugosities and small pits. Pritchard (1993) reported that in adult Dogania the carapacial suture contacts widen into gaps, with loss of sutural intercontact and proliferation of fibrous tissue, resulting in loss of bone contact and a generalized carapacial flexibility that accommodates retraction of the neck and enlarged head. The plastron is whitish to cream or gray, and bears four weakly developed (hyo-hypoplastral, xiphiplastral) callosities. Often only the xiphiplastral callosities are distinguishable. Epiplastral arms are long and slender and nearly meet anterior to the entoplastron. The entoplastron has long arms which lie at obtuse or right angles to the plastral midline. The skull is large with a bony snout at least as long as the diameter of the orbit and a mandibular symphysis narrower than the diameter of the orbit; it lacks a median ridge. Triturating surfaces of the maxilla also lack longitudinal ridges. The head is brown to olive, black, or gray with black lines. A black medial stripe may pass along the top of the snout and between the orbits, another may pass on each side from the snout through the orbit, and a small black stripe may pass diagonally backward from the orbit. In the young, a reddish blotch occurs behind the eye and over the tympanum on each side of the head; this fades in adults. The chin has black vermiculations, and the neck and outer surface of the limbs are olive to blackish with some small yellow spots.
There are 66 chromosomes; 16 metacentric and submetacentric, 12 subtelocentric, and 38 acrocentric and telocentric (Stock, 1972).
Males have long, thick tails; the female tail is short.
Distribution
Dogania subplana ranges from southern Myanmar and Thailand southward through Malaysia to Sumatra, Java, and Borneo; a Philippines record (De Rooij, 1915) is questionable according to Taylor (1920).
Habitat
This softshell lives in clean, rocky, shallow, fast-running upland streams (Smith, 1931; Pritchard, 1993). It often hides beneath irregular rocks and large stones in the stream bed, its flexible, flattened shell allowing it to do so. Judging from locality data of museum specimens, Indonesian and Malayan Dogania do not always live in hill streams (Balázs L. Farkas, pers. comm.).
Natural History
Rudloff (1990) reported that a captive female in the period January to June laid three to four clutches of 3-7 round (22 to 31 mm), hard-shelled eggs. The eggs hatched after approximately 72 days (incubated at 28°C). The hatchlings are very intensely marked and have a pattern of ocelli on the carapace.
Remark
The genera Pelodiscus, Palea, and Dogania are closely related (Meylan, 1987).
IUCN Red List Status (1996)
Not listed.