Creaser's mud turtle
Kinosternon creaseri is poorly known. Its oval, dark-brown carapace is of medium size (to 12.1 cm) and highest behind the center. The posterior carapacial profile is nearly vertical. A weak median keel is present in adults, and a pair of low dorsolateral keels is also present on juveniles. The 1st vertebral is about as broad as or slightly broader than long, vertebrals 2-4 are broader than long, and the 5th is small and almost as long as broad. Marginals 10-11 are elevated above the preceding nine. The double-hinged plastron is long, wide, and practically capable of closing completely. It is unnotched posteriorly. The anterior plastral lobe is longer than the abdominal scute, but slightly shorter than the posterior lobe, and the gular scute is more than half the length of the anterior plastral lobe. The plastral formula is: an > abd > gul > hum > fem >< pect. Axillary and inguinal scutes barely touch across the bridge. Plastron and bridge are yellowish brown with dark seams. The head is large with a slightly projecting snout and a strongly hooked upper jaw. Both head and neck are dark brown to black above with very fine light speckles; the sides and ventral surfaces are lighter. The jaws contain dark streaking, and the limbs are grayish to brown. Vinculae are absent.
Males have longer, thicker tails with a terminal horny spine, and grow slightly larger than females.
Kinosternon creaseri is restricted to the northern and central portions of the Yucatán Peninsula in the states of Yucatán, Quintana Roo, and Campeche, Mexico.
Females from Yucatán have a wider plastral hindlobe than those from Quintana Roo and Campeche, whereas males have longer plastra and longer interabdominal seams (Iverson, 1988). Furthermore, Creaser's mud turtles from Quinatana Roo are generally darker, with pale yellow on the neck and sides of the head, while turtles from central Yucatán are lighter and have bright yellow markings on the neck, sides of the head, and the anterior surface of the forelegs (Iverson, 1988). Duellman (1965) collected two specimens from a solution cave which had pale tan carapaces, pale cream-colored plastra, and pale grayish brown limbs and heads; perhaps this was an adaptation to their dimly lighted habitat.
This turtle lives in the drier part of the Yucatán Peninsula, a region where no surface streams exist, and occurs in temporary pools in undisturbed forest. During rainstorms it may travel about on land. Most of the year seems to be spent aestivated in the humus layer of the forest floor (Iverson, 1988).
A female dissected by Iverson (1988) contained a single egg (38.2 x 19.1 mm; 8.9 g) and two enlarged follicles, suggesting two to three clutches of a single egg may be laid annually.
This species is mainly carnivorous, feeding on insects and snails, but also palm fruits are occasionally taken (Iverson, 1988).
As Kinosternon creaseri behaves very aggressively toward conspecifics, Iverson (1988) suggested this species may be territorial.
IUCN Red List Status (1996)
Lower risk: near threatened.