Field Guide

Aquatic Invertebrates

Showing 1 - 7 of 7 results
Media
Photo of a spothanded crayfish viewed through creekwater.
Species Types
Scientific Name
Faxonius punctimanus (formerly Orconectes punctimanus)
Description
The spothanded crayfish is moderately large and usually has a noticeable black spot on each pincer near the base of the movable finger. In Missouri, it is found mostly in Ozark waterways in the southeastern quarter of the state, from Callaway, Montgomery, and Warren counties south.
Media
Photo of several prosobranch pond snails crawling on a rock.
Species Types
Scientific Name
Over 20 Missouri species in former subclass Prosobranchia
Description
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.
Media
Photo of pulmonate snail crawling on rock
Species Types
Scientific Name
Over 30 Missouri species in former subclass Pulmonata
Description
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.
Media
Photo of a stonefly naiad clinging to a rock underwater
Species Types
Scientific Name
There are hundreds of species in North America
Description
Stonefly larvae are aquatic and somewhat resemble the larvae of mayflies and damselflies. Their presence usually indicates good water quality.
Media
Photograph of several mosquito larvae resting at water surface
Species Types
Scientific Name
There are about 50 species of mosquitoes in our state.
Description
The larvae of mosquitoes, often called “wrigglers,” have a large head and thorax and a narrow, wormlike abdomen; they typically hang just below the water surface. When disturbed, they wriggle downward.
Media
Photo of a pink planarian on a rock.
Species Types
Scientific Name
Dugesia, Planaria, and other genera
Description
Unlike their parasitic cousins in the flatworm group, turbellarians, or planarians, are tiny carnivores or detritus-eaters that glide smoothly across submerged leaves and other objects.
Media
Water springtails congregate in water above soggy dead leaves
Species Types
Scientific Name
Podura aquatica
Description
In early spring, clusters of water springtails float on the surface of quiet waters, on muddy banks, and on protruding objects. Adults are bluish gray with reddish appendages.
See Also

About Aquatic Invertebrates in Missouri

Missouri's streams, lakes, and other aquatic habitats hold thousands of kinds of invertebrates — worms, freshwater mussels, snails, crayfish, insects, and other animals without backbones. These creatures are vital links in the aquatic food chain, and their presence and numbers tell us a lot about water quality.