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spiny softshell turtle

spiny softshell turtle
Apalone spinifera

Image of eastern spiny softshell turtleDescription

This medium to large turtle is unmistakable, with its flat, smooth shell and long pig-like nose. The rounded tan, brown, or olive carapace is marked with black dots or circles in juveniles and males, and dark blotches in adult females. The plastron is white, with gray patches over the plastral bones. Both carapace and plastron lack scutes and are quite soft and flexible. The name "spiny" comes from the small spines at the front of the carapace. The neck is very long, and a yellowish, black-bordered stripe is usually visible on the sides of the head. Females are larger and darker and have shorter tails than males.

Adult Male Carapace Length:

5 to 9 inches ( 12.7 to 23 cm).

Adult Female Carapace Length:

7 to 19 inches (18 to 48 cm).

Habitat and Habits

These turtles occur in rivers, large lakes, and impoundments; sandy or muddy bottoms are favored. They will bask on logs or sloping banks but spend much time buried in sand or mud in shallow water where they can use their snorkel-like noses and long necks to get air. Softshells can breathe underwater by absorbing oxygen through throat and cloacal linings. This may explain their sensitivity to pollutants that also kill fish. Crayfish are reported to be the favorite food of this species, though they will also eat aquatic insects, snails, tadpoles, and fish.

Spiny softshells are sometimes called "leatherbacks" or "pancake turtles." They are very fast swimmers and are surprisingly agile on land, though they rarely venture from the water except for nesting. Their main defenses are concealment and fast escape. When handled they can deliver a painful bite with their sharp jaws.

Image of eastern spiny softshell turtleReproduction

Most nesting occurs in June, with females seeking open, sunny sites near the water and depositing from 4 to 38 spherical, brittle-shelled eggs in each nest. Most hatchlings emerge in August or September, though some overwinter in the nest and emerge in spring.

Range and Status

Softshells are locally common in the southern three-quarters of the Lower Peninsula. Populations in some areas have been reduced or eliminated by water pollution and exploitation by humans. The Department of Natural Resources regulates the taking of spiny softshells with closed seasons, minimum size and possession limits, and special licensing and trapping regulations. Check with the DNR for current rules before capturing these turtles.

Image of eastern spiny softshell turtleAcknowledgement

James Harding
MSU Museum
Michigan State University
East Lansing, MI 48824
(517) 353-7978