The oval to elliptical carapace (to 32 cm) is only slightly domed and is wider posteriorly than anteriorly. The medial keel is prominent, and the posterior marginals flared and serrated. Longitudinal rows of shallow rugosities give each vertebral and pleural a wrinkled appearance. Vertebrals 1 and 5 are broader than long, but 2-4 are about equal in width and length. The carapace varies from grayish brown to yellowish olive or dark gray. In young individuals, a yellow bar may occur on each pleural and marginal, but these fade with age. The plastron is widest at the hindlobe, which bears a shallow posterior notch. Its scute formula is: abd > an > pect >< gul > fem > hum. There are usually no markings on the cream to yellow plastron, although faint blotches may occur on the gulars and humerals or along the seams. The head is of moderate size and its snout is short and bluntly rounded. The upper jaw is only slightly notched medially, and the ridge on its triturating surface is low. The head is gray to olive, and any light stripes present are faded and hardly discernible. Several faded cream to white stripes occur on the chin, and a whitish "mustache" may lie below the nostrils on the upper jaw. Neck, limbs, and tail are also gray to olive, and the forelimbs and neck may contain faded light stripes.
Like other Trachemys, T. terrapen has 50 chromosomes; 26 macrochromosomes (16 metacentric or submetacentric, 10 telocentric or subtelocentric), and 24 microchromosomes (Bickham and Baker, 1976b; Bickham and Carr, 1983).
Males have elongated foreclaws and longer, thicker tails than females; however, females grow larger than males. Occasionally, large, white males are found in some of the southern rivers.
Trachemys terrapen occurs on Jamaica; it has been introduced on Cat Island, Eleuthera, and south Andros in the Bahamas. Pseudemys felis Barbour, 1935 is synonymous with T. terrapen (Seidel and Adkins, 1987).
Shallow ponds with mud bottoms and abundant aquatic vegetation seem to be the normal habitat.
While courting, the male swims backward in front of the female and strokes the sides of her face with the elongated claws of his outstretched forefeet. Copulation occurs under water. Clutch size is unknown, but Lynn and Grant (1940) dissected a female in April that contained four shelled eggs 39 x 24 mm and four additional large yolks.
Nesting probably occurs from May into June. Hatchlings have dark-bordered yellow stripes on the head, neck, limbs, and tail; Williams (1956) showed a photograph of a juvenile T. terrapen with an extensive dark blotch on the center of its plastron.
Adult T. terrapen are apparently omnivorous. They consume large quantities of aquatic plants, but are still attracted to animal baits.
This species is fond of basking in both the wild and captivity.
IUCN Red List Status (1996)