Field Guide

Aquatic Invertebrates

Showing 1 - 10 of 38 results
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.
Media
Photo of a papershell crayfish, also called calico crayfish.
Species Types
Scientific Name
Faxonius immunis (formerly Orconectes immunis)
Description
The calico crayfish is rather plain: gray-green with a pale central zone along the middle of the carapace and abdomen. The pincers are orange-tipped, and in mature males are tinged with purple. It is usually only found in the northern half of the state.
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
elktoe
Species Types
Scientific Name
Alasmidonta marginata
Description
The elktoe is one of many Missouri mussels with a declining population.
Media
fatmucket
Species Types
Scientific Name
Lampsilis siliquoidea
Description
The fatmucket was a favorite species harvested for the button industry in the early 1900s.
Media
Photo of a fishfly larva crawling among rocks in an aquarium.
Species Types
Scientific Name
Chauliodes, Neohermes, and Nigronia spp. (in eastern US)
Description
Fishfly larvae look a lot like their cousins the hellgrammites, but they lack cottony or hairy gill tufts along the abdomen, and they have 2 short, fleshy tails at the hind tip.
Media
fragile papershell
Species Types
Scientific Name
Leptodea fragilis
Description
A widespread mussel that relies on freshwater drum as host fish for the developing 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.
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.