Field Guide

Aquatic Invertebrates

Showing 1 - 10 of 35 results
Media
Photo of backswimmer, side view
Species Types
Scientific Name
About 32 North American species in the family Notonectidae
Description
Sometimes called “water bees” or “water wasps,” backswimmers are predaceous and can deliver a painful bite if mishandled. True to their name, they swim belly-up, and their backs are keeled like a boat, which makes back-swimming easier.
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 Cajun dwarf crayfish.
Species Types
Scientific Name
Cambarellus puer
Description
The Cajun dwarf crayfish is small, reddish brown to gray, with a paired series of dark, wavy stripes or dashes along the dorsal surface. In Missouri, it occurs in our southeastern lowlands.
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
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
ellipse
Species Types
Scientific Name
Venustaconcha ellipsiformis and V. pleasii
Description
These small mussels use darters, a type of fish, as hosts for their young.
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 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.