Field Guide

Aquatic Invertebrates

Showing 1 - 10 of 52 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
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
Photo of caddisfly larva with case made of detritus
Species Types
Scientific Name
Various species in the order Trichoptera
Description
The aquatic larvae of caddisflies are famous for building portable, protective cases out of local materials, including grains of sand, bits of leaves and twigs, and other debris. The adults are mothlike.
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 Caney Mountain cave crayfish out of water on a wet, red-coated cave rock.
Species Types
Scientific Name
Orconectes stygocaneyi
Description
One of three species of cave crayfish in Missouri, the Caney Mountain cave crayfish is known from only one location. Like many other cave invertebrates, this species is whitish and is blind.
Media
Two Chinese mysterysnails, out of water, resting on a white surface, with a ruler nearby for scale
Species Types
Scientific Name
Cipangopaludina chinensis malleata (syn. Bellamya chinensis)
Description
The Chinese mysterysnail is a nonnative invasive species quickly taking over urban waters throughout the state. Never release aquarium species or aquarium water into natural aquatic habitats. Learn about and practice clean boating techniques so that you do not accidentally spread invasive aquatic species.
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.
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.