Field Guide

Aquatic Invertebrates

Showing 1 - 10 of 23 results
Media
Photo of an alderfly larva among rocks and gravel in an aquarium.
Species Types
Scientific Name
Sialis spp.
Description
Alderfly larvae look a lot like their cousins the fishflies, but instead of having pairs of fleshy tails, they have only a single tail pointing straight back.
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 caddisfly larva with case made of detritus
Species Types
Scientific Name
Various species in the order Trichoptera
Description
The aquatic larvae of caddisflies are famous for building portable, protective cases out of local materials, including grains of sand, bits of leaves and twigs, and other debris. The adults are mothlike.
Media
Clam shrimp on a white fabric surface
Species Types
Scientific Name
Cyclestherida, Laevicaudata, and Spinicaudata (orders or suborders)
Description
Clam shrimp have their carapace shaped like a pair of clam shells and they can close it tightly when disturbed. But they are not clams: they have tiny, jointed shrimplike legs and bristly, feathery antennae.
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.
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.