Field Guide

Aquatic Invertebrates

Showing 1 - 10 of 25 results
Media
Photo of an aquatic isopod in an aquarium, crawling on a rock.
Species Types
Scientific Name
Freshwater members of the crustacean order Isopoda
Description
Everyone knows about terrestrial sowbugs and pillbugs, but many isopod species are aquatic. Missouri has several isopods that live in streams, ponds, rivers, and caves.
Media
Photo of a belted crayfish, also called Big River crayfish.
Species Types
Scientific Name
Faxonius harrisonii (formerly Orconectes harrisonii)
Description
The belted crayfish is medium-small, tan, with a distinctive pattern of alternating olive-green and reddish-brown bands on the abdominal segments. It is found only in the Big River and its tributaries.
Media
Photo of a Big Creek crayfish.
Species Types
Scientific Name
Faxonius peruncus (formerly Orconectes peruncus)
Description
The Big Creek crayfish is moderately small and brown. It has a very localized distribution centered in Big Creek and its tributaries, in the St. Francis River basin. It lacks bright colors, but blackish specks and blotches occur over the top surfaces of the body and pincers.
Media
Photo of a bristly cave crayfish, viewed from the side.
Species Types
Scientific Name
Cambarus setosus
Description
The bristly cave crayfish is a whitish crayfish with small, unpigmented eyes and long, slender pincers with noticeable setae (bristles). It lives in caves in the Springfield Plateau region of the Ozarks.
Media
Clam shrimp on a white fabric surface
Species Types
Scientific Name
Cyclestherida, Laevicaudata, and Spinicaudata (orders or suborders)
Description
Clam shrimp have their carapace shaped like a pair of clam shells and they can close it tightly when disturbed. But they are not clams: they have tiny, jointed shrimplike legs and bristly, feathery antennae.
Media
Photo of a coldwater crayfish.
Species Types
Scientific Name
Faxonius eupunctus (formerly Orconectes eupunctus)
Description
The coldwater crayfish has a very localized distribution in the Eleven Point River system. It is stout, with a blue-green head and pincers and dark, rust-brown carapace. It is an imperiled species.
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 devil crayfish.
Species Types
Scientific Name
Lacunicambarus aff. diogenes (syn. Cambarus diogenes)
Description
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.
Media
Photo of a freckled crayfish.
Species Types
Scientific Name
Cambarus maculatus
Description
The freckled crayfish is powerfully built, yellowish tan, with numerous conspicuous black spots on its pincers, carapace, and abdomen. It is largely restricted to the Courtois Hills section of the Meramec River basin.
Media
Photo of a golden crayfish viewed through the surface of creek water.
Species Types
Scientific Name
Faxonius luteus (formerly Orconectes luteus)
Description
The golden crayfish varies in color from olive green to golden yellow. Many body parts are trimmed with red. A dark band crosses the head just in front of the cervical groove, and another crosses the carapace at its junction with the abdomen. It's a wide-ranging species.
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.