The eastern spiny softshell, A. s. spinifera , has larger spots on the shell. The two subspecies are weakly defined and the size of the spots vary among individuals. The spiny softshell is found in suitable habitat throughout Minnesota. The only areas lacking records at this time are much of northern Minnesota. Habitat Spiny softshells are found in rivers, streams, and large lakes with sandy or muddy bottoms.
Sandbars are important for basking and egg laying sites.
These turtles are active from late April and early May to late September and October. They bury themselves in mud or sand at the bottoms of rivers or lakes. They are diurnal and sleep at night underwater buried in sand or mud in the shallows or among submerged trees. They are one of Minnesota's most aquatic turtle species. They bask on sand or mud bars or on large logs and rocks, but always at the waters edge.