Field Guide

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

Zebra mussels are named for their shells, which have alternating light and dark bands. They are a highly invasive nonnative species. Learn how to prevent their spread.

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.

The Chinese mysterysnail is a nonnative invasive species quickly taking over urban waters throughout the state. Never release aquarium species or aquarium water into natural aquatic habitats. Learn about and practice clean boating techniques so that you do not accidentally spread invasive aquatic species.

Of Missouri’s two species of freshwater shrimp, the Mississippi grass shrimp is by far the most common and widespread.

Of Missouri’s two species of freshwater shrimp, the Ohio River shrimp is certainly the rarest. It was thought to be extirpated from our state but was rediscovered recently in the Mississippi River.

At one time the most valuable shell to the commercial button industry, the ebonyshell is now classified as endangered in Missouri and is a candidate for federal endangered status.