Cyclemys tcheponensis

(Bourret, 1939)
Northern stripe-necked leaf turtle

Recognition
The carapace is elongated (to 22 cm) in adults, but rounder in juveniles. A single low medial keel is present on adults, and the posterior carapacial border is serrated. Carapacial scutes in juveniles bear some rugosities. The carapace may range from mahogany to olive in juveniles or gray brown to olive brown in adults. The plastron is notched posteriorly, and its formula is quite variable: abd >< pect > gul >< an > fem >< hum. The plastron varies from pinkish or red in juveniles to yellow or light brown in adults; merged dark radiations often give the impression of an all-dark plastron in larger individuals (Fritz et al., 1997). Hatchlings are characterized by a central dark plastral marking (Fritz et al., 1997). Head morphology is like that of C. dentata; the head is dark olive dorsally with numerous dark mottlings, and four yellow, orange, or pink stripes extend from the neck forward over the side of the head. The most dorsal of these passes above the orbit and onto the snout; a second broad stripe stops at the orbit; below this a third, narrower stripe passes below the orbit and along the upper jaw; and a fourth passes along the lower jaws. The throat is mottled with small dark spots. Skin of the limbs is grayish brown to olive.
The full chromosome compliment consists of 52 chromosomes (Bickham, 1981).
Males have longer, thicker tails.

Distribution
Cyclemys tcheponensis has been taken from northern Thailand, northern Vietnam, and the border region between central Vietnam and Laos (Fritz et al., 1997).

Habitat
Nutphand (1979) reported it lives in streams and brooks in mountainous areas, but spends much time on land.

Natural History
All we know about the life history of this turtle comes from Nutphand (1979), who reported it is agile, lively, and becomes tame in captivity. It is omnivorous, and 10-15 eggs are laid per clutch (although this is doubtful, since the eggs seem too large for such a clutch size; John B. Iverson, pers. comm.).

Remark
Controversy has surrounded this species ever since it was described by Bourret (1939), who reported it to be intermediate between Heosemys grandis and H. spinosa. Unfortunately, the holotype is a juvenile, the adult being unknown at that time, and it was unclear whether or not a plastral hinge developed. Consequently it has been assigned and reassigned to several batagurine genera. McDowell (1964) thought the holotype to be merely a variation of Cyclemys dentata with the entoplastron abnormally far forward. However, McMorris (1976) studied fifteen specimens from Indochina which matched the description by Bourret (1939), and redescribed and compared it to C. dentata. Nutphand (1979), Pritchard (1979), Ernst and Barbour (1989), Iverson (1992) and Fritz et al. (1997) all thought C. tcheponensis valid, but a discriminate functions analysis performed by Iverson (in Iverson and McCord, 1997) did not support the distinctiveness of this species.

IUCN Red List Status (1996)
Not listed.

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