Field Guide

Crayfish are freshwater aquatic invertebrates that look a lot like small lobsters, to which they are related. There are about 38 species of crayfish in Missouri.

Unlike their parasitic cousins in the flatworm group, turbellarians, or planarians, are tiny carnivores or detritus-eaters that glide smoothly across submerged leaves and other objects.

The St. Francis River crayfish is rather small and dark brown, with blackish blotches or specks over the upper surfaces of the pincers, carapace, and abdomen. It is limited to the St. Francis River and its tributaries.

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.

Shufeldt’s dwarf crayfish is small, reddish brown to gray, with a paired series of dark, wavy stripes or dashes along the dorsal surface. In Missouri, it occurs in our southeastern lowlands and north along the Mississippi River floodplain.

The shrimp crayfish is medium-small, light reddish brown to gray, and thickly dusted with darker specks. Its noselike rostrum is unusually long, with the tip longer than the base, and the pincers are narrow and weak. It is found in the Bootheel.