(Krefft, 1876)
Red-bellied short-necked turtle
Recognition
The brown oblong carapace (to 25.5 cm) is broader posteriorly than anteriorly. It is somewhat domed but lacks a vertebral keel in adults; small juveniles are keeled. The cervical scute is well-developed, and the vertebrals are broader than long. Posteriorly, the marginal rim is smooth and somewhat flared; undersides of the marginals are red. The narrow plastron is notched posteriorly and lacks a hinge. It is yellow with a broad lateral border of red pigment. The intergular scute is longer than broad, longer than the length of the interhumeral seam. The plastral formula is: pect > fem > abd > an >< intergul < gul > hum. The bridge is composed of parts of the pectoral and abdominal scutes with no axillary and only small inguinal scutes present. It is yellow with some reddish markings. On the olive head, a yellow stripe runs from the tip of the snout through the orbit to and above the tympanum, and another yellow stripe may be present along the upper jaw. A broken red stripe runs along the lower jaw to the neck, often extending to the plastron. Two yellow barbels are present on the chin, and the light-colored maxillary and mandibular sheaths are prominent. The neck is dark gray dorsally, but ventrally lighter gray with red streaks. Limbs and tail are gray anteriorly and white posteriorly with red streaks. A series of enlarged narrow horizontal scales occurs on the anterior surface and lateral margin of the forelegs and on the outer margins of the hindlegs. The red pigment is more prominent in juveniles, but fades to a pinkish salmon with age.
Males have long, thick tails and narrow posterior plastral notches, while females have short tails and wide posterior plastral notches.
Distribution
Emydura subglobosa ranges mainly in Irian Jaya and Papua New Guinea, but it has also been found in the Jardine River at the northern tip of the Cape York Peninsula, Queensland, Australia.
Geographic Variation
Emydura albertisii Boulenger, 1888b is considered a synonym of E. subglobosa.
Habitat
Basically a riverine dweller, Emydura subglobosa also occurs in lakes and lagoons.
Natural History
According to Norris (1996), during courtship the male closely trails the female with neck and head extended and directed towards her rear. He brings his nose close to or touches the female's cloacal region, which often causes her to twitch her tail. The male then moves around the side of the female's carapace until he faces her in front in an off-center position. If she continues to swim on, he increases his efforts, but if she stops swimming he performs a series of rapid strokes toward her face with his forefeet (palms toward her). His claws do not always brush her cheeks during this behavior, and the stroking is often alternated from one side of her face to the other. The male follows this with rapid head bobbing and repetitive blinking of his eyes. The female usually surfaces at this time, and the male follows, surfacing in front of her, touches his nose to hers, and expels water through his nostrils. These last behaviors may be repeated several times.
The females lay an average clutch of 10 eggs in September (Cann, 1978). A 21 cm female kept by Ernst laid 5 eggs between 17 and 21 November 1980. These had white, brittle shells and were elongated. Their measurements ranged from 31 x 19 mm to 44 x 20 mm (all but one was over 40 mm in length).
In the wild, red-bellied short-necked turtles are probably carnivores, feeding primarily on mollusks, crustaceans, and aquatic insects, but in captivity they thrive on a fish diet. Captives kept by us were shy and remained hidden most of the time; they seldom basked. Cann (1978) reported that large numbers occur in some New Guinea rivers.
Remark
Georges and Adams (1996) consider the Australian yellow-faced Emydura australis in part synonymous with E. subglobosa. Wells and Wellington (1985) named the Jardine River population Tropicochelymys goodei, but without proper diagnosis.
IUCN Red List Status (1996)
Not listed.