It is characterized by smaller dark spots on the shell. 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 Iowa. 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 April and 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 Iowas most aquatic turtle species. They bask on sand or mud bars or on large logs and rocks, but always at the waters edge.