Field Guide

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 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 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.

The bristly cave crayfish is a whitish crayfish with small, unpigmented eyes and long, slender pincers with noticeable setae (bristles). It lives in caves in the Springfield Plateau region of the Ozarks.

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 Salem cave crayfish lives in caves in the Missouri Ozarks. Its localized distribution makes its populations vulnerable to catastrophes that might pollute or damage their cave environment.