Northern Prairie Wildlife Research Center
Description: This turtle has an olive to light brown soft upper shell with a sandpapery texture. Bumps or spines are found on the front edge of its shell. The legs and long, snake-like head have dark spots or streaks. Each nostril has a ridge on its inner edge. Females range from 7-17 inches (180-432 mm); males are smaller (5-8 inches, 125-200 mm).
Habitat and Habits: This species is found on mud flats, sandbars and soft sandy or muddy bottoms with some aquatic vegetation in lakes, reservoirs, fast-flowing rivers, ponds along rivers and intermittent streams. The spiny softshell usually feeds early in the morning and late in the evening on crayfish, aquatic insects, mollusks, fishes, amphibians and some vegetation. It may be observed basking on logs or along the shoreline, resting in shallow water with sand or mud covering its shell or floating near the surface in deep water. This turtle is active from April or May through October.
Breeding occurs during late spring. The female lays 4-32 round, white eggs in a nest she locates on land in an open area of sand, gravel or soft soil near water. Eggs hatch during the early fall months. Hatchlings overwinter in the nest and emerge the following spring. The adult spiny softshell overwinters by burying itself beneath several inches of sand or mud in a river or lake bottom. This turtle is very quick on land and in the water, and is aggressive and able to inflict wounds with its sharp claws and bites.
Distribution: This turtle is distributed from Montana to southem Quebec, south to northem Mexico and the Florida panhandle. It has been found in the South Dakota counties of Buffalo, Clay, Davison, Fall River, Gregory, Lyman, Minnehaha, Pennington, Tripp and Yankton.
Conservation Measures: The spiny softshell may be threatened by loss of natural river habitat. Further inventories are needed to more accurately describe its South Dakota range.