Field Guide

Round pigtoes are more rounded than Wabash pigtoes. Usually, the nacre (the shell lining) is white, but in rare individuals it is bright pink.

Nacre color varies from purple to pink to white. In smaller rivers, the shell is much thinner.

Among all the mussels of Missouri, this is perhaps the easiest to recognize: As the shell grows, large knobs are produced, first on one shell and then on the other, in an alternating pattern.

Sometimes called the blue-point, this mussel species is widely distributed in Missouri rivers and is occasionally found along reservoir margins.

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

The shell of this mollusk is large and impressive in overall size. Although fairly flat, it can be more than 8 inches long. A large wing on the heelsplitter can be painful if you step on it.

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 Chinese mysterysnail is a nonnative invasive species quickly taking over urban waters throughout the state. Never release aquarium species or aquarium water into natural aquatic habitats. Learn about and practice clean boating techniques so that you do not accidentally spread invasive aquatic species.

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.