Field Guide

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.

Gilled snails are one of two main groups of aquatic snails in Missouri (the other group is the "lunged" snails). Gilled snails, or prosobranchs, breathe with gills and possess a hard trapdoor-like operculum. They are most common in the Ozarks.

Pulmonate, or lunged snails breathe via a lunglike pulmonary cavity, and they lack the hard trapdoor-like operculum found in gilled snails. Except for in the Ozarks, pulmonate snails predominate in most of the aquatic regions in our state.

Ramshorn snails are easy to identify at a glance, because the shell is a flat, disklike coil. Like other pulmonate aquatic snails, they lack the hard horny “trapdoor” possessed by other types of aquatic snails.

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.

The pincers of Meek's crayfish are sprinkled with many blackish spots. There is a dark spot near the tubercle at the base of the moveable finger. In Missouri, this rare crayfish occurs in only a few tributaries of Table Rock Lake in Stone County.

Before buttons were made of plastic, they were made of shell. Because only white buttons were in demand, the coppery-purple shell of this species made it worthless for the button industry.