Field Guide

Aquatic Invertebrates

Showing 1 - 10 of 14 results
Media
Photo of a woodland crayfish.
Species Types
Scientific Name
Faxonius hylas (formerly Orconectes hylas)
Description
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.
Media
Photo of a saddleback crayfish.
Species Types
Scientific Name
Faxonius medius (formerly Orconectes medius)
Description
The saddleback crayfish has a bold blackish band across the hind margin of the carapace and lacks dark blotches or specks. The pincers are broad and powerful. It occurs in the Big and Meramec river drainages.
Media
Photo of a ringed crayfish.
Species Types
Scientific Name
Faxonius neglectus (formerly Orconectes neglectus)
Description
The ringed crayfish is olive green to reddish tan and usually has black or brown rings around the pincer tips. In Missouri it is found in clear, rocky Ozark streams in the southwestern quarter.
Media
Photo of a vernal crayfish.
Species Types
Scientific Name
Procambarus viaeviridus
Description
Adult vernal crayfish are rusty red with a blackish wedge-shaped central stripe along the length of the abdomen. In Missouri, this species occurs only in our southeastern swamps and is usually only seen in February and March.
Media
Photo of a spothanded crayfish viewed through creekwater.
Species Types
Scientific Name
Faxonius punctimanus (formerly Orconectes punctimanus)
Description
The spothanded crayfish is moderately large and usually has a noticeable black spot on each pincer near the base of the movable finger. In Missouri, it is found mostly in Ozark waterways in the southeastern quarter of the state, from Callaway, Montgomery, and Warren counties south.
Media
giant floater
Species Types
Scientific Name
Pygandon grandis
Description
When a floater dies, this large mussel with a thick shell will actually rise to the water surface and float as it decays.
Media
Photo of a longpincered crayfish.
Species Types
Scientific Name
Faxonius longidigitus (formerly Orconectes longidigitus)
Description
The longpincered crayfish is large and colorful, with very long, slender, blue-green pincers that are studded with prominent yellowish knobs. It is restricted to the White River basin in the Ozarks.
Media
elephantear mussel half-buried in a gravel substrate
Species Types
Scientific Name
Elliptio crassidens
Description
Today found only in the Meramec River, the elephantear has been classified as endangered in Missouri and is a candidate for federal endangered status.
Media
pond mussel
Species Types
Scientific Name
Bivalve molluscs in order Unionoida
Description
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.
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.
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.