Chelydra rossignonii

(Bocourt, 1868)
Mexican snapping turtle

Recognition
This large freshwater turtle reaches a carapace length of 38.9 cm. Its somewhat rounded carapace is heavily serrated posteriorly, and has three longitudinal keels that become lower with age. The anterior width of the 3rd vertebral is more than 25% of the maximum carapace width. The carapace is brown to olive or olive-black; some light radiations or small spots may occur on each scute, particularly in younger individuals, or the carapace may be unicolored. The plastron is cream to yellow, tan or gray. The bridge is 6-8% of the carapace length; the gular scute is subdivided into two in most individuals, and 3-4 inframarginals may be present. The abdominal scute is usually less than twice as broad as long, and the length of the plastral forelobe is usually more than 40% of the carapace width. The large head has a narrow, pointed snout, and 4-6 barbels are present on the chin. Neck tubercles are long and pointed. Skin color is gray to black.
Males are larger than females, have longer preanal tail lengths, and the vent usually behind the posterior carapacial rim.

Distribution
The Mexican snapping turtle occurs in the Atlantic lowland drainages of Mexico from central Veracruz southward across the base of the Yucat√°n Peninsula and southern Campeche to western Belize, Guatemala, and west-central Honduras.

Geographic Variation
Unknown.

Habitat
It prefers slow moving waters with soft bottoms and abundant hiding places (patches of aquatic vegetation, submerged logs, etc.): marshes, swamps, ponds, lakes, and large streams and rivers.

Natural History
A clutch of 20-30 eggs is laid each year between April and June. Hatchlings are dark gray to black with white spots on the marginals; the plastron is grayish with white mottling.
Like other snapping turtles, C. rossignonii is omnivorous, feeding mostly on fish, frogs and other small aquatic animals, but also taking some plant materials.

IUCN Red List Status (1996)
Not listed.

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