Field Guide

Aquatic Invertebrates

Showing 1 - 10 of 16 results
Media
Photo of an aquatic isopod in an aquarium, crawling on a rock.
Species Types
Scientific Name
Freshwater members of the crustacean order Isopoda
Description
Everyone knows about terrestrial sowbugs and pillbugs, but many isopod species are aquatic. Missouri has several isopods that live in streams, ponds, rivers, and caves.
Media
Two pairs of Asian clam shells, still hinged together, showing exterior and interior
Species Types
Scientific Name
Corbicula fluminea
Description
The Asian clam is a nonnative, invasive species that lives in a variety of aquatic habitats. It has thick shells with distinctly ridged, concentric rings and a yellowish-brown to dark brown shell covering.
Media
Fingernail clam in a person’s hand
Species Types
Scientific Name
Pisidium, Sphaerium, and Musculium spp.
Description
Fingernail clams, also called pill clams or pea clams, are members of a family of small to tiny freshwater clams that are common but rarely noticed. They occur in a variety of aquatic habitats.
Media
Photo of a freshwater jellyfish
Species Types
Scientific Name
Craspedacusta sowerbii (syn. C. sowerbyi)
Description
You may have heard about stinging jellyfish in the ocean, but did you know that there are similar creatures living in the freshwater of Missouri? Fortunately, they’re harmless!
Media
pond mussel
Species Types
Scientific Name
Bivalve molluscs in order Unionoida
Description
Secretive and seldom seen, freshwater mussels are extraordinarily diverse in Missouri. We have nearly 70 species within our borders. Many are declining, and several are endangered.
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 a deer fly larva, probably in a petri dish, on a gray background.
Species Types
Scientific Name
Tabanus, Chrysops, and related genera
Description
The larvae of horse and deer flies are fairly straight, segmented, wormlike maggots that are tan, whitish, or brownish. They are aquatic or live in mud, and most are predaceous.
Species Types
Scientific Name
Various species in the genus Hydra
Description
We’ve all seen aquariums and pictures of tropical saltwater invertebrates such as corals, jellyfish and anemones—but did you know that there are similar creatures living in the freshwater habitats of Missouri?
Media
lilliput
Species Types
Scientific Name
Toxolasma parvus
Description
These diminutive mollusks are the smallest of Missouri’s freshwater mussels.
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.
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.