Field Guide

A widespread mussel that releases its larvae in tiny red packages to attract fish hosts.

This favored habitat of this vulnerable species is large streams or rivers in firm sand and mud. The bumps on the shell may help to anchor it in the river bottom.

The uniform shell thickness and hard, white nacre made this mussel a favorite for button manufacturing, in the days before most buttons were made of plastic.

The longpincered crayfish is large and colorful, with very long, slender, blue-green pincers that are studded with prominent yellowish knobs. It is restricted to the White River basin in the Ozarks.

This endangered native mussel lives in flowing waters of large streams among gravel and cobble.

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.

Pulmonate, or lunged snails breathe via a lunglike pulmonary cavity, and they lack the hard trapdoor-like operculum found in gilled snails. Except for in the Ozarks, pulmonate snails predominate in most of the aquatic regions in our state.

Ramshorn snails are easy to identify at a glance, because the shell is a flat, disklike coil. Like other pulmonate aquatic snails, they lack the hard horny “trapdoor” possessed by other types of aquatic snails.

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.