Field Guide

Aquatic Invertebrates

Showing 1 - 10 of 22 results
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 a collared water scavenger beetle showing back.
Species Types
Scientific Name
Beetles in the family Hydrophilidae
Description
Water scavenger beetles are a mostly aquatic family. They are similar to predaceous diving beetles, but unlike them many have a distinctive spine running down the center of their bellies.
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 deer fly larva, probably in a petri dish, on a gray background.
Species Types
Scientific Name
Tabanus, Chrysops, and related genera
Description
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.
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
Photo of a water scorpion, genus Ranatra, captured in a jar of pond water.
Species Types
Scientific Name
Ranatra spp. and Nepa apiculata
Description
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.
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 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.
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.