Identification
The Alligator Snapping Turtle is the largest freshwater turtle in North America.
Larger than the Common snapper, it possesses many similar characteristics, such
as a large head, a long tail, and a small cross-shaped grayish brown plastron.
In its mouth, the Alligator snapper possesses a “lure,” a wormlike
projection that is moved to attract prey into the turtle’s mouth. As well
as having an extra row of scutes on each side, the carapace also features prominent
dorsal keels that are raised and curved posteriorly. The carapace is generally
brown or blackish in color, is very rough and often has algae growing on it.
The turtle’s skin is dark brownish to grey on top, and lighter on the
bottom.
Distribution and Status
Sticking mostly to river systems that drain into the Gulf of Mexico, the Alligator
Snapping Turtle can be found in the north from Kansas, Illinois, and Indiana,
to the Gulf; including Florida and eastern Texas (US
distribution map; Midwest
distribution map).
Ecology
Alligator Snapping Turtles are massive and have been documented as weighing
in at well over 200 pounds, with a shell length of 79cm (31 in) and heads as
large as 24 cm (9.5 in)! They are highly aquatic and prefer large slow-flowing
streams or tributaries with large holes and mud at the bottom. They can also
be found in canals, lakes, oxbows, swamps, ponds and bayous.
Threats and Management Issues
Alligator snappers are threatened by overharvesting for food in many areas.
In the Midwest, the Alligator Snapping Turtle is State Endangered in Indiana
and Illinois. The species is also found in Iowa, and is considered imperiled
in Missouri.
Resources
Ernst. C. H., J. E. Lovich and R. W. Barbour. 1994. Turtles of the United States and Canada. Smithsonian Institution Press, USA.
General reference guides and websites.
Links to more information on the Alligator Snapping Turtle outside the Herp Center
University of Michigan Museum of Zoology - A detailed site with a few photos under the 'media' section.
Bruce Kingsbury, Director
Center for Reptile and Amphibian Conservation and Management
Science Building
Indiana-Purdue University
2101 East Coliseum Blvd.
Fort Wayne, IN 46805-1499