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 Ozark crayfish is light brown to reddish brown with numerous black specks on the pincers and often on the abdomen as well. The pincers are broad and powerful. It lives in the White and Black stream systems.

The ringed crayfish is olive green to reddish tan and usually has black or brown rings around the pincer tips. In Missouri it is found in clear, rocky Ozark streams in the southwestern quarter.

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.

Hubbs' crayfish is powerfully built, olive tan or reddish brown, with a narrow blackish band where the carapace and abdomen join. It has a limited range within the Ozarks of southern Missouri and northern Arkansas.

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

The Arkansas brokenray only occurs in streams that flow south off of the Salem and Springfield plateaus, so it is found only in about the southern quarter of Missouri.

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