Vietnamese leaf turtle
The uniformly dark-gray to black carapace (to 21 cm; Ron de Bruin, pers. comm.) is low arched, or depressed, and contains three longitudinal keels. The medial vertebral keel is best developed and prominent in adults; the two dorsolateral keels, which run along the dorsal portions of the pleurals, are low and almost non-existent in older individuals, but strongly developed in juveniles. Vertebral 1 is wider anteriorly than posteriorly, but the 5th is the opposite. Vertebrals 2-4 are about as broad as long. Posterior marginals are not serrated; those anterior and lateral are slightly upturned. The plastron is well-developed, but does not completely cover the shell opening. Its anterior lobe is truncate, and the posterior lobe contains a deep anal notch. The plastral formula is: abd < pect > fem > an > hum >< gul; however, the seams between the pectorals, abdominals, and femorals are often nearly equal in length. The plastron is sutured to the carapace, and the bridge is well-developed (its length is 40-50% that of the plastron). Axillary and inguinal scutes are present and their bony buttresses are very strongly developed, almost touching the neural bones; the axillary buttress touches the 1st rib. Such extensive buttressing is usually associated with freshwater turtles that inhabit deep waters (Boulenger, 1889), such as Callagur, Batagur, Hardella, Kachuga and Orlitia, and forms two extensive lateral chambers housing the lungs. The plastron is yellow to orange with a large black blotch on each scute and on the underside of each marginal. A longitudinal black bar crosses the bridge. The head is somewhat pointed, as the snout is projected forward. The upper jaw is medially notched, and the triturating surfaces of the jaws are narrow and lack ridges. The head is dark brown to black with several pairs of yellow stripes. One pair begins dorsal to the nostrils and passes backward on each side above the orbits to the neck. A second wider pair starts at the nostrils and runs backward on each side through the orbit and tympanum to the neck (often broadening on the tympanum). Still a third pair begins on the upper jaw below the nostrils and runs backward along each jaw margin to the side of the neck. The lower jaw is yellow, but the chin varies from yellowish to dark brown. The neck is dark dorsally, but lighter ventrally. Limbs are dark gray or black, and the toes are fully webbed. The tail is not overly elongated, but is thicker at the base in the males.
Mauremys annamensis is known only from central Vietnam.
Lowland marshes and slow-moving streams are inhabited.
Hatchlings have 35 mm carapaces and weigh 6 g (Ron de Bruin, pers. comm.). Its behavior in the wild is unknown, but captives accept both vegetable (lettuce and fruits) and animal (fish) foods.
The taxonomic position of Mauremys annamensis has been confused for some time, but Iverson and McCord (1994) shed light on the problem when they presented data to support its inclusion as a full species in the genus Mauremys.
IUCN Red List Status (1996)