Field Guide

Aquatic Invertebrates

Showing 81 - 90 of 92 results
Photo of a deer fly larva, probably in a petri dish, on a gray background.
Horse and Deer Fly Larvae
Tabanus, Chrysops, and related genera
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.
Photo of hellgrammite
Hellgrammite
Corydalus cornutus
Hellgrammites are the aquatic larval form of eastern dobsonflies. They are fiercely predaceous and look a little like centipedes. Anglers often use them as bait.
Photo of a horsehair worm in an aquarium
Horsehair Worms
About 350 species scientifically described.
Adult horsehair worms can be nearly 3 feet long and live in water. They are practically featureless, smooth, aquatic worms that writhe into knots and curls.
Photo of a water scorpion, genus Ranatra, captured in a jar of pond water.
Water Scorpions
Ranatra spp. and Nepa apiculata
Water scorpions remain still, looking like a random bit of plant material. Then they suddenly grab their prey and deliver disabling fluids with a quick jab of their knifelike beak.
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.
Two pairs of Asian clam shells, still hinged together, showing exterior and interior
Asian Clam
Corbicula fluminea
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.
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.
Bluefer
Bleufer (Purpleshell)
Potamilus purpuratus
Like the pink heelsplitter and fragile and pink papershells, the bleufer uses freshwater drum as a host.
pink heelsplitter
Pink Heelsplitter
Potamilus alatus
A large dorsal wing and purple lining make identification of this widespread mussel easy.
pond mussel
Pondmussel
Ligumia subrostrata
This widespread species is one of the few Missouri mussels successful in shallow ponds and lakes.
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.