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Smooth Softshell Turtle

Smooth Softshell Turtle
Apalone mutica
(Order Testudines, Family Trionychidae)

Diagnosis: The Smooth Softshell Turtle gets its name from the lack of scutes on its body, resulting in a smooth covering. The “shell” is leathery and flexible. It is a medium to large aquatic species ranging in size from 17-35 cm in females and 11-18 cm in males. The smooth shell is olive to dark brown with a pattern of darker irregular blotches. The plastron is reduced leaving the limbs and body exposed. The limbs are olive to light brown with no pattern and the feet are shaped like paddles.

Habitat: Apalone mutica is found in large rivers and streams with moderate to fast current. Males prefer shallow water with emergent sandbars, while females prefer deeper more open water except when they are nesting.

Reproduction: Females reach sexual maturity at 17-22 cm in length. This usually coincides with their seventh year of life. Males mature at a smaller size. Males are fairly territorial, and smaller males will seek out larger females. Males will chase and bite other males and it’s not uncommon to see turtles with “battle wounds” in the spring.  After mating, the female digs a nest with her back feet 6 to 9 inches deep. The nests are usually dug in sand bars, sand banks, and islands in full sunlight from May to July. Average clutch size is 10.4 and the range is from 3 to 26. Hatchlings emerge from August through September and hatchling plastron length ranges from 20-29 mm.

Diet: Smooth Softshells are carnivorous but some vegetation has been found in their stomach, probably ingested by accident. They feed in shallow moving water. They have been reported to feed on fish, frogs, tadpoles, aquatic insects, mudpuppies, crayfish, snails and worms.

Predators and Defense Mechanisms: Nests may be dug up by skunks, raccoons and crows. After hatching, juveniles are susceptible to being preyed upon by fish, snakes, other turtles, wading birds, and various mammals. They are camouflaged rather well and this, along with burrowing habits, probably helps them avoid detection by predators. Humans may affect populations of this turtle during fishing and also by pollution of their habitat. Because of the smooth softshell turtle's long maturation period, population recovery may take many years.

Distribution: The smooth softshell turtle occurs from the Florida Panhandle to eastern Texas, North to South Dakota, and east to western Pennsylvania. It is probably found throughout Kansas, but it is more abundant in the eastern half of the state

Similar Species: Western Spiny Softshell

How to Observe:  Along rivers densities are fairly high. During the day they can be seen basking on sandbars in or near the water. At night they can be seen foraging and swimming since they are primarily nocturnal.


Caldwell, J. and J.T. Collins. 1981.  Turtles in Kansas. 

Carr, Archie.  1995.  Handbook of Turtles: The Turtles of the United States, Canada, and Baja California.  

Photo Credits:


Submitted by:  Jesse Busenbarrick, July 2013.


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