Field Guide

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

Sometimes called the blue-point, this mussel species is widely distributed in Missouri rivers and is occasionally found along reservoir margins.

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.

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.

Bryozoans are tiny, filter-feeding invertebrates. They create colonies that can be mossy, branching, or round and jellylike.

Water scavenger beetles are a mostly aquatic family. They are similar to predaceous diving beetles, but unlike them many have a distinctive spine running down the center of their bellies.

Giant water bugs are huge aquatic insects that frequently fly around electric lights at night. They are infamous for the painful bite they can deliver, but fish, birds — and some people — find them tasty!