Spiny Softshell

Photo Credit: Wisconsin DNR, Robert Hay

Family: Trionychidae (Softshell turtles)
Status: Common
Size: carapace: fem. 7 - 18 in., m. 5 - 9.5 in.

The spiny softshell can be distinguished from the smooth softshell by the presence of two yellow, black-bordered lines along each side of the head, a row of spines along the front edge of the carapace, and a raised nasal septum, giving the nostrils a "C" shape.

Species range (darker) in Wisconsin

Young and males have olive-gray carapaces with small black markings often appearing like thin donuts. Adult females have dark olive or tan carapaces with brown and gray mottling. Spiny softshells can be found in large rivers, lakes and reservoirs, especially those with muddy or sandy bottoms. Unlike smooth softshells, spiny softshells are often aggressive when seized, and can inflict painful bites. Both softshell species, especially juveniles and sub-adults, spend significant amounts of time buried in the substrate in shallow water, especially at night, to remain concealed while inactive. Spiny softshells feed on a variety of animals, including fish, invertebrates, mollusks and carrion.