Field Guide

The shield crayfish is small and tan, with a pattern of paired blackish dashes along the surface of the carapace and abdomen. The pincers are narrow, with short, abruptly tapering fingers. In Missouri it occurs only in our southeast counties.

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.

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

These diminutive mollusks are the smallest of Missouri’s freshwater mussels.

Shaped like a checkered gunstock, with its unique, turned-down edge, pistolgrips are easy to identify.

This widespread species is one of the few Missouri mussels successful in shallow ponds and lakes.

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

Missouri may have the largest number of spectaclecase mussels left in the world. These elongated shellfish can live for 60 years or more.

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

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.