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34 Deertoe, Truncilla truncata Description: This is a smaller mussel, seldom getting much over 80- 90mm. The shell is thick and has a somewhat triangular outline. The anterior end is rounded while the posterior end is pointed with a prominent posterior ridge. When you put both valves together, the posterior slopes form a flattened area. The beaks of the two valves curl around until they meet each other. The beak sculpture, such as it is, is some barely visible double-looped ridges. The nacre is white. The exterior can vary from greens, browns, tans or yellowish with numerous green rays. The rays may have darker zig-zag markings within them. Older individuals often darken to the point that the rays are hard to see. Similar species: Juvenile Deertoe are similar to the Fawnsfoot though adults get much larger. The Fawnsfoot tends to be more elongate and its posterior ridge isn't as sharp. The Fawnsfoot may have visible beak sculpture consisting of several fine looped ridges. Hosts: Freshwater drum, sauger Conservation status: G5, N5, S3. Live or fresh dead specimens have only been found in only two areas (Missouri River and Weeping Water Creek) which means the species could be vulnerable to catastrophic events. Habitats used: Medium to large rivers in mud, sand, or gravel (Cummings and Mayer 1992). Found in a variety of substrates ranging from mud-gravel to large rocks in moderately swift water. (Oesch 1995). Generalized in substrates used, often a composite of fine gravel with sand and mud in medium and large rivers. Can adapt to lakes (Parmalee and Bogan 1998). Rivers and lakes in packed sand and gravel. Rarely found in smaller streams (Watters et.al. 2009). Distribution: Widespread in Mississippi River basin. From Texas north into Minnesota, through the Great Lakes states into Pennsylvania then following the Appalachians through Mississippi to the Gulf. Collection notes: Live or fresh dead Deertoe have been found in the Missouri River downstream of Gavins Point Dam and in Weeping Water Creek in Cass County. There is an archeological record from Sarpy County. Comments: This is a small mussel that prefers large rivers so records may be scant for that reason. Archeological data suggests it has always been uncommon in this state. That it is seldom found in smaller streams may indicate that it's host fish is a big river fish.

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