Field Guide

Aquatic Invertebrates

Showing 1 - 10 of 28 results
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
Photo of a whirligig beetle viewed from above
Species Types
Scientific Name
Species in the beetle family Gyrinidae
Description
Groups of whirligig beetles swim on the water surface in quick, random patterns, searching for food. They have two pairs of eyes — one pair above water, one pair below — to help them quickly and accurately capture their prey.
Media
Photo of crane fly larva
Species Types
Scientific Name
There are over 500 species of crane flies in North America.
Description
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.
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
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
Photograph of several mosquito larvae resting at water surface
Species Types
Scientific Name
There are about 50 species of mosquitoes in our state.
Description
The larvae of mosquitoes, often called “wrigglers,” have a large head and thorax and a narrow, wormlike abdomen; they typically hang just below the water surface. When disturbed, they wriggle downward.
Media
Photo of a leech
Species Types
Scientific Name
Various species in the subclass Hirudinea
Description
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.
Media
Photo of caddisfly larva with case made of detritus
Species Types
Scientific Name
About 1,500 species in North America north of Mexico
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
Photo of a spotted fishing spider perched on the water's surface amid floating duckweed plants
Species Types
Scientific Name
Dolomedes spp., Tetragnatha spp., and others
Description
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.
Media
Water boatman viewed from above
Species Types
Scientific Name
About 125 species in North America in the family Corixidae
Description
Water boatmen are one of the few aquatic true bugs that are not predatory and do not bite people. Instead, they suck juices from algae and detritus. Only a few types eat other small aquatic creatures.
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.