Field Guide

Aquatic Invertebrates

Showing 1 - 10 of 35 results
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 an aquatic tubificid worm among rocks in an aquarium.
Tubificid Worms (Tubifex Worms)
Tubifex spp. and other aquatic tubificid annelids
Tubificid worms, as a group, include the tubifex worms that aquarists feed to their pet fish. These segmented worms are related to earthworms and like them are detritus eaters.
Red midge fly larva, side view, in a petri dish
Midge Fly Larvae
Nearly 1,100 species in North America
Midge larvae look something like thin aquatic inchworms. They can be clear, whitish, olive, tan, or bright red. They occur in a variety of aquatic habitats. As adults, they resemble mosquitoes but they never bite.
Water springtails congregate in water above soggy dead leaves
Water Springtail
Podura aquatica
In early spring, clusters of water springtails float on the surface of quiet waters, on muddy banks, and on protruding objects. Adults are bluish gray with reddish appendages.
Photo of a St. Francis River crayfish.
St. Francis River Crayfish
Faxonius quadruncus (formerly Orconectes quadruncus)
The St. Francis River crayfish is rather small and dark brown, with blackish blotches or specks over the upper surfaces of the pincers, carapace, and abdomen. It is limited to the St. Francis River and its tributaries.
Photo of a woodland crayfish.
Woodland Crayfish
Faxonius hylas (formerly Orconectes hylas)
The woodland crayfish is stout, reddish tan to dark brown, with numerous blackish specks and blotches on the pincers, carapace, and abdomen. It occurs only in Missouri, especially in the Black River and its tributaries.
Photo of an Ozark crayfish.
Ozark Crayfish
Faxonius ozarkae (formerly Orconectes ozarkae)
The Ozark crayfish is light brown to reddish brown with numerous black specks on the pincers and often on the abdomen as well. The pincers are broad and powerful. It lives in the White and Black stream systems.
Photo of a painted devil crayfish standing on a sandy substrate
Painted Devil Crayfish
Lacunicambarus ludovicianus (syn. Cambarus ludovicianus)
The painted devil crayfish is a burrowing lowland species. In Missouri, it is known from only a few locations in the Bootheel. Its overall color is olive green to blue, with reddish and cream markings.
Photo of a grassland crayfish, also called prairie crayfish.
Grassland Crayfish (Prairie Crayfish)
Procambarus gracilis
The grassland crayfish is rather uniformly colored either bright red or reddish and has broad, powerful pincers. It inhabits prairies and grasslands from Wisconsin and Indiana to Texas, including grasslands in northern and western Missouri.
Photo of a devil crayfish.
Devil Crayfish
Lacunicambarus aff. diogenes (syn. Cambarus diogenes)
The powerfully built devil crayfish is usually a uniform olive or tan, without obvious blotches or spots. It digs underground burrows, often with mud chimneys, and has a wide distribution.
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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.