Field Guide

Aquatic Invertebrates

Showing 1 - 10 of 14 results
Media
Gray, speckled, translucent gelatinous blob cut in half to show structure
Species Types
Scientific Name
Freshwater species in the phylum Bryozoa
Description
Bryozoans are tiny, filter-feeding invertebrates. They create colonies that can be mossy, branching, or round and jellylike.
Media
Photo of a spothanded crayfish viewed from above on white background.
Species Types
Scientific Name
About 36 species in Missouri
Description
Crayfish are freshwater aquatic invertebrates that look a lot like small lobsters, to which they are related. There are about 36 species of crayfish in Missouri.
Media
deertoe
Species Types
Scientific Name
Truncilla truncata
Description
A common mussel in some areas, deertoe have decorative green markings.
Media
elktoe
Species Types
Scientific Name
Alasmidonta marginata
Description
The elktoe is one of many Missouri mussels with a declining population.
Media
Photo of a fishfly larva crawling among rocks in an aquarium.
Species Types
Scientific Name
Chauliodes, Neohermes, and Nigronia spp. (in eastern US)
Description
Fishfly larvae look a lot like their cousins the hellgrammites, but they lack cottony or hairy gill tufts along the abdomen, and they have 2 short, fleshy tails at the hind tip.
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
giant floater
Species Types
Scientific Name
Pygandon grandis
Description
When a floater dies, this large mussel with a thick shell will actually rise to the water surface and float as it decays.
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.
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
pimpleback
Species Types
Scientific Name
Quadrula pustulosa
Description
While the pimpleback is usually bumpy, some individuals are perfectly smooth.
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.