Field Guide

Gilled snails are one of two main groups of aquatic snails in Missouri (the other group is the "lunged" snails). Gilled snails, or prosobranchs, breathe with gills and possess a hard trapdoor-like operculum. They are most common in the Ozarks.

The Neosho midget crayfish is a subdued mottled brown, with a prominent black band crossing the carapace near its junction with the abdomen. The pincers are broad and powerful. This small, stout crayfish is found in the Neosho stream drainage of southwestern Missouri and northwestern Arkansas.

Williams' crayfish is small and rather plain, without bright colors or bold markings. It has a pale, vase-shaped zone along the middle of the dark olive-tan carapace. It is found only in the upper White River drainage of Missouri and Arkansas.

The pincers of Meek's crayfish are sprinkled with many blackish spots. There is a dark spot near the tubercle at the base of the moveable finger. In Missouri, this rare crayfish occurs in only a few tributaries of Table Rock Lake in Stone County.

At one time the most valuable shell to the commercial button industry, the ebonyshell is now classified as endangered in Missouri and is a candidate for federal endangered status.

Before buttons were made of plastic, they were made of shell. Because only white buttons were in demand, the coppery-purple shell of this species made it worthless for the button industry.

The sheepnose has been classified as endangered in Missouri and is a candidate for federal endangered status.

The elktoe is one of many Missouri mussels with a declining population.