Field Guide

The coldwater crayfish has a very localized distribution in the Eleven Point River system. It is stout, with a blue-green head and pincers and dark, rust-brown carapace. It is an imperiled species.

These small mussels use darters, a type of fish, as hosts for their young.

These diminutive mollusks are the smallest of Missouri’s freshwater mussels.

The snuffbox has been classified as endangered in Missouri and is a candidate for federal endangered status. Perhaps it should also be a candidate for a new common name, since the popularity of snuff-taking is long past.

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.

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.