Field Guide

The spothanded crayfish is moderately large and usually has a noticeable black spot on each pincer near the base of the movable finger. In Missouri, it is found mostly in Ozark waterways in the southeastern quarter of the state, from Callaway, Montgomery, and Warren counties south.

The calico crayfish is rather plain: gray-green with a pale central zone along the middle of the carapace and abdomen. The pincers are orange-tipped, and in mature males are tinged with purple. It is usually only found in the northern half of the state.

The coldwater crayfish has a very localized distribution in the Eleven Point River system. It is stout, with a blue-green head and pincers and dark, rust-brown carapace. It is an imperiled species.

These small mussels use darters, a type of fish, as hosts for their young.

The fatmucket was a favorite species harvested for the button industry in the early 1900s.

The Arkansas brokenray only occurs in streams that flow south off of the Salem and Springfield plateaus, so it is found only in about the southern quarter of Missouri.

A common mussel in some areas, deertoe have decorative green markings.

When a floater dies, this large mussel with a thick shell will actually rise to the water surface and float as it decays.

While the pimpleback is usually bumpy, some individuals are perfectly smooth.