Pictured Above: The Spiny Softshell can be characterized by its long snout (top right, bottom right), as well as its leathery, flexible shell (bottom left). The Spiny Softshell can also be distinguished from its relative, the Smooth Softshell, by the tiny projections located on its carapace directly behind the head (bottom right).
Description: The Spiny Softshell is one of the larger turtles found in the LaCrosse area, with adult females attaining carapace lengths of 7 to 18 inches and males reaching 5 to 9 inches. They are easily distinguishable from other turtles by their flat, leathery shell, long neck and long pointed snout. The Spiny Softshell is also characterized by the ridge of tiny projections that are found near the anterior edge of the carapace (pictured above). In most cases, the carapace is olive green to tan with dark spots. These spots tend to be darker in males and juveniles than in females. The head and legs of these turtles likewise have numerous dark blotches and lines. Spiny Softshells are members of the family Trionychidae.
Habitat/Ecology: These are primarily a river turtle, but have been reported in large lakes and impoundments as well. They are said to prefer mud or sand bottoms and gravel or sand beaches. Spiny Softshells will periodically bask on fallen trees or along the rivers’ edge but most of their time is spent buried in the sediments of shallow water. In fact, I have never witnessed them "basking" but only coming to the surface for a quick breathe of air before returning to the depths. They are said to use their cryptic coloration to remain concealed among the sediments and ambush their prey. When buried, it is reported that Spiny Softshells can use their long necks and snouts as a “snorkel” with which to breathe. They eat crayfish, insects, mollusks, fish, and carrion. The nest building season is in June and early July and eggs are spherical, not elliptical. This is when adults are most likely to be encountered. Hatchlings generally emerge during late August and mid-September. Like all turtle species, hatchlings are most susceptible to predation, while the only threat to adults are humans.
Remarks: These turtles are quick on land and females will often make a mad dash for the river if disturbed during nest-building. If captured, they will claw and reach out to snap with their extremely long necks. They may also release a musky scent. They can be cantankerous and should not be handled. If left alone, they are no threat whatsoever. These turtles seem to be more tolerant of human-induced habitat degradation than some other aquatic turtles.
The Mississippi river is a perfect habitat for the Spiny Softshell. As a child, I found them along the Yahara River near my parents home in Stoughton, WI (Dane Co.), and they seem to be much more fond of rivers than stagnant water. In La Crosse, I have found them near Green Island and believe they can exist almost anywhere in which the habitat is correct.
Within the state, these turtles can also be found along the Wisconsin and Rock Rivers.