(Schmidt, 1928)
Central Antillean slider
Recognition
The oval, slightly domed carapace (to 24 cm) is widest at the midpoint or posterior to the midpoint, serrated posteriorly, and has a low, blunt medial keel. Each scute may contain longitudinal rugosities. Vertebrals are broader than long. The color in adults is gray, brown, olive, or black. In juveniles, yellow streaks occur on the pleurals, vertebrals, and marginals. Melanism develops in older males. The plastron is well-developed, and has a slight posterior notch. The plastral formula is: abd > an >< pect >< gul >< fem > hum. The yellow plastron may be immaculate or there may be a black seam-following pattern. Faded olive ocelli may be present on the undersides of the marginals. The head is short and the snout blunt or pointed. The upper jaw is medially notched. The head is gray to olive with cream to yellow stripes; its supratemporal stripe is reddish brown. Neck, limbs, and tail are gray to olive with cream to yellow stripes.
The diploid chromosome total is 50; 26 macrochromosomes (16 metacentric or submetacentric, 10 telocentric or subtelocentric) and 24 microchromosomes (Bickham and Baker, 1976b).
Males have longer, thicker tails with the vent beyond the carapace margin. Females are larger and have shorter tails with the vent under the carapace.
Distribution
Trachemys stejnegeri occurs on Hispaniola, Puerto Rico, and Great Inagua, Bahamas; it has been introduced on Paradise Island, Marie-Galante Island, and Culebra and Viesques Islands (Seidel, 1988).
Geographic Variation
Three subspecies are known (Seidel, 1988). Trachemys stejnegeri stejnegeri (Schmidt, 1928), the Puerto Rican slider, has an elongated, moderately domed carapace, brown to brownish olive skin, a pointed, somewhat elongated snout, and a plastral pattern which spreads out away from the seams and onto the broad surface of the scutes, especially the gulars. Posteriorly the plastral pattern is less distinct. It is found on Puerto Rico and has been introduced on Marie-Galante, French West Indies. The Dominican slider, T. s. vicina (Barbour and Carr, 1940), occurs only on Hispaniola. It has an elongated, moderately domed carapace, grayish olive skin, a somewhat pointed, elongated snout, and a seam-following plastral pattern which sometimes has additional ocelli on each scute. T. s. malonei (Barbour and Carr, 1938), the Inagua slider, has an elliptical to oval, high-domed carapace, gray to olive skin, a blunt to rounded snout, and a plastron which is either immaculate yellow or has a dark seam-following pattern or a few dark marks restricted to the upper and lower surfaces of the gulars. It occurs on Great Inagua Island, Bahamas. As can be seen from the descriptions, these subspecies are rather poorly differentiated.
Habitat
Trachemys stejnegeri is restricted to freshwater ponds, swamps, streams, and rivers with soft bottoms and abundant aquatic plants.
Natural History
The male strokes the sides of the female's face with his elongated foreclaws during courtship. The nesting season begins in April and probably extends into July. The white eggs are elongated (38-48 x 22-31 mm) and have pliable shells. Three to 14 eggs may be laid in each clutch, and one to three clutches are deposited each season (Hodsdon and Pearson, 1943; Inchaustegui Miranda, 1973). In the Dominican Republic, the incubation period is 57-79 days (Inchaustegui Miranda, 1973). Hatchlings (31-35 mm) are more brightly colored than adults and their medial keel is more pronounced.
In the Bahamas, the females dig saucer-shaped, symmetrical nests about 6-7.5 cm deep and several centimeters in diameter. There, Hodsdon and Pearson (1943) observed a female scratch away the soil from the top of a nest in August, and two days later young turtles emerged from it. To the best of our knowledge this is the only report of a female turtle aiding its young to escape from the nest, and it is probably erroneous. This type of behavior is common in crocodilians but unknown in other reptiles.
Adults are predominantly herbivorous, but aquatic insects are also taken.
IUCN Red List Status (1996)
Lower risk: near threatened.