Field Guide

Adult White River crawfish are usually a deep burgundy red with a black V-shaped stripe on the abdomen. Juveniles are gray with dark spots scattered over the carapace. In Missouri, this species mostly occurs in the Bootheel and north along the Mississippi River.

The virile crayfish is large, reddish brown or green, and lacks prominent markings. The pincers are green with orange tips and are studded with whitish knobs. Paired dark blotches run along the abdomen. This species is widespread.

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.

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

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.