Field Guide

Aquatic Invertebrates

Showing 1 - 10 of 81 results
Media
Photo of an alderfly larva among rocks and gravel in an aquarium.
Species Types
Scientific Name
Sialis spp.
Description
Alderfly larvae look a lot like their cousins the fishflies, but instead of having pairs of fleshy tails, they have only a single tail pointing straight back.
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 spotted fishing spider perched on the water's surface amid floating duckweed plants
Species Types
Scientific Name
Dolomedes spp., Tetragnatha spp., and others
Description
A variety of spiders are adapted for live on and around water. Many of these are called fishing spiders. Several have the ability to run across the water’s surface. Some build webs, others do not.
Media
brokenray
Species Types
Scientific Name
Lampsilis reeveiana
Description
The Arkansas brokenray only occurs in streams that flow south off of the Salem and Springfield plateaus, so it is found only in about the southern quarter of Missouri.
Media
Two pairs of Asian clam shells, still hinged together, showing exterior and interior
Species Types
Scientific Name
Corbicula fluminea
Description
The Asian clam is a nonnative, invasive species that lives in a variety of aquatic habitats. It has thick shells with distinctly ridged, concentric rings and a yellowish-brown to dark brown shell covering.
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 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
Gray, speckled, translucent gelatinous blob cut in half to show structure
Species Types
Scientific Name
Freshwater species in the phylum Bryozoa
Description
Bryozoans are tiny, filter-feeding invertebrates. They create colonies that can be mossy, branching, or round and jellylike.
Media
butterfly
Species Types
Scientific Name
Ellipsaria lineolata
Description
The butterfly is one of the most beautiful of Missouri’s mussels.
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.