Field Guide

Most people are repulsed by leeches. But once you get past the fact that many species are parasitic bloodsuckers, you will discover that they are fascinating creatures with an important role in nature.

Often overlooked by people, but eagerly sought by fish, Missouri’s amphipods resemble shrimplike sowbugs. Scuds live in various aquatic habitats, and several species inhabit caves.

Everyone knows about terrestrial sowbugs and pillbugs, but many isopod species are aquatic. Missouri has several isopods that live in streams, ponds, rivers, and caves.

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

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

The mapleleaf spawns in the summer, using catfish as a host.

Unlike most other freshwater mussels, this species is hermaphrodic: An individual mussel can be both male and female.

A large dorsal wing and purple lining make identification of this widespread mussel easy.

This species enjoys the same geographic distribution in our state as the pink heelsplitter, and it generally resembles that species, too. But as the name suggests, the pink papershell usually has a thinner shell and is smaller. Also, it prefers rather shallow water with a good current.

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