Field Guide

Aquatic Invertebrates

Showing 1 - 10 of 21 results
Photo of an alderfly larva among rocks and gravel in an aquarium.
Alderfly Larvae
Sialis spp.
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.
Photo of a spotted fishing spider perched on the water's surface amid floating duckweed plants
Aquatic Spiders
Dolomedes spp., Tetragnatha spp., and others
A variety of spiders are adapted for live on and around water. Many of these are called fishing spiders. Several have the ability to run across the water’s surface. Some build webs, others do not.
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 caddisfly larva with case made of detritus
Caddisfly Larvae
Various species in the order Trichoptera
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.
Photo of crane fly larva
Crane Fly Larvae
There are over 500 species of crane flies in North America.
Crane fly larvae are tan or gray grubs that live in aquatic habitats or in moist places on the ground. The harmless adults resemble huge mosquitoes.
ellipse
Ellipse and Bleedingtooth
Venustaconcha ellipsiformis and V. pleasii
These small mussels use darters, a type of fish, as hosts for their young.
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.
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 several prosobranch pond snails crawling on a rock.
Gilled Aquatic Snails (Prosobranch Pond Snails)
Over 20 Missouri species in former subclass Prosobranchia
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.
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.
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.