Field Guide

Round pigtoes are more rounded than Wabash pigtoes. Usually, the nacre (the shell lining) is white, but in rare individuals it is bright pink.

The longpincered crayfish is large and colorful, with very long, slender, blue-green pincers that are studded with prominent yellowish knobs. It is restricted to the White River basin in the Ozarks.

The Mammoth Spring crayfish has a very localized distribution: In our state, it lives only in the Warm Fork of Spring River, in Oregon County. It is reddish brown, and its broad, powerful pincers have numerous blackish specks on their basal parts.

Today found only in the Meramec River, the elephantear has been classified as endangered in Missouri and is a candidate for federal endangered status.

This endangered native mussel lives in flowing waters of large streams among gravel and cobble.

Williams' crayfish is small and rather plain, without bright colors or bold markings. It has a pale, vase-shaped zone along the middle of the dark olive-tan carapace. It is found only in the upper White River drainage of Missouri and Arkansas.

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.

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.