Field Guide

Aquatic Invertebrates

Showing 11 - 20 of 21 results
yellow sandshell
Yellow Sandshell
Lampsilis teres
The uniform shell thickness and hard, white nacre made this mussel a favorite for button manufacturing, in the days before most buttons were made of plastic.
Bluefer
Bluefer (Purpleshell)
Potamilus purpuratus
Like the pink heelsplitter and fragile and pink papershells, the bluefer uses freshwater drum as a host.
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.
Photo of an Ohio shrimp with small grayish pincers in the foreground.
Ohio Shrimp
Macrobrachium ohione
Of Missouri’s two species of freshwater shrimp, the Ohio River shrimp is certainly the rarest. It was thought to be extirpated from our state but was rediscovered recently in the Mississippi River.
Photo of a leech
Leeches
Various species in the subclass Hirudinea
Most people are repulsed by leeches. But once you get past the fact that many species are parasitic bloodsuckers, you will discover that they are fascinating creatures with an important role in nature.
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 spothanded crayfish viewed from above on white background.
Crayfishes
About 38 species in Missouri
Crayfish are freshwater aquatic invertebrates that look a lot like small lobsters, to which they are related. There are about 38 species of crayfish in Missouri.
Photo of a fishfly larva crawling among rocks in an aquarium.
Fishfly Larvae
Chauliodes, Neohermes, and Nigronia spp. (in eastern US)
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.
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.
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.