Field Guide

Aquatic Invertebrates

Showing 1 - 5 of 5 results
Media
Photo of a Caney Mountain cave crayfish out of water on a wet, red-coated cave rock.
Species Types
Scientific Name
Orconectes stygocaneyi
Description
One of three species of cave crayfish in Missouri, the Caney Mountain cave crayfish is known from only one location. Like many other cave invertebrates, this species is whitish and is blind.
Media
Photo of several prosobranch pond snails crawling on a rock.
Species Types
Scientific Name
Over 20 Missouri species in former subclass Prosobranchia
Description
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.
Media
Photo of Williams' crayfish.
Species Types
Scientific Name
Faxonius williamsi (formerly Orconectes williamsi)
Description
Williams' crayfish is small and rather plain, without bright colors or bold markings. It has a pale, vase-shaped zone along the middle of the dark olive-tan carapace. It is found only in the upper White River drainage of Missouri and Arkansas.
Media
Photo of a spothanded crayfish viewed from above on white background.
Species Types
Scientific Name
About 38 species in Missouri
Description
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.
Media
Photo of a pink planarian on a rock.
Species Types
Scientific Name
Dugesia, Planaria, and other genera
Description
Unlike their parasitic cousins in the flatworm group, turbellarians, or planarians, are tiny carnivores or detritus-eaters that glide smoothly across submerged leaves and other objects.
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.