Field Guide

Aquatic Invertebrates

Showing 1 - 8 of 8 results
Photo of a water nymph crayfish, side view of specimen carefully arranged against black background
Water Nymph Crayfish
Faxonius nais (formerly Orconectes nais)
The water nymph crayfish is normally found in streams but can also be found in a variety of other aquatic habitats. It is greenish brown or brown with no prominent markings. Its known distribution in Missouri is spotty.
ellipse
Ellipse and Bleedingtooth
Venustaconcha ellipsiformis and V. pleasii
These small mussels use darters, a type of fish, as hosts for their young.
lilliput
Lilliput
Toxolasma parvus
These diminutive mollusks are the smallest of Missouri’s freshwater mussels.
pond mussel
Freshwater Mussels
Bivalve molluscs in order Unionoida
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.
Two Chinese mysterysnails, out of water, resting on a white surface, with a ruler nearby for scale
Chinese Mysterysnail
Cipangopaludina chinensis malleata (syn. Bellamya chinensis)
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.
Hydras
Various species in the genus Hydra
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?
Gray, speckled, translucent gelatinous blob cut in half to show structure
Bryozoans (Moss Animals)
Freshwater species in the phylum Bryozoa
Bryozoans are tiny, filter-feeding invertebrates. They create colonies that can be mossy, branching, or round and jellylike.
Photo of a pink planarian on a rock.
Turbellarians (Planarians; Free-Living Flatworms)
Dugesia, Planaria, and other genera
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.
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.