Field Guide

Aquatic Invertebrates

Showing 1 - 10 of 14 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 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
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 grassland crayfish, also called prairie crayfish.
Species Types
Scientific Name
Procambarus gracilis
Description
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.
Media
Photo of a leech
Species Types
Scientific Name
Various species in the subclass Hirudinea
Description
Who isn't repulsed by leeches! Yet once you get past the fact that many species are parasitic bloodsuckers, you will discover that they are fascinating creatures.
Media
Red midge fly larva, side view, in a petri dish
Species Types
Scientific Name
Nearly 1,100 species in North America
Description
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.
Media
Photo of a ramshorn snail on a wet rock.
Species Types
Scientific Name
Gyraulus, Helisoma, Menetus, Micromenetus, Planorbula spp.
Description
Ramshorn snails are easy to identify at a glance, because the shell is a flat, disklike coil. Like other pulmonate aquatic snails, they lack the hard horny “trapdoor” possessed by other types of aquatic snails.
Media
round pigtoe
Species Types
Scientific Name
Pleurobema sintoxia
Description
Round pigtoes are more rounded than Wabash pigtoes. Usually, the nacre (the shell lining) is white, but in rare individuals it is bright pink.
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.