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.

The powerfully built devil crayfish is usually a uniform olive or tan, without obvious blotches or spots. It digs underground burrows, often with mud chimneys, and has a wide distribution.

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.

Adult vernal crayfish are rusty red with a blackish wedge-shaped central stripe along the length of the abdomen. In Missouri, this species occurs only in our southeastern swamps and is usually only seen in February and March.

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.

The Cajun 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.

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.