Aquatic Invertebrates
Media
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
Species Types
Scientific Name
Toxolasma parvus
Description
These diminutive mollusks are the smallest of Missouri’s freshwater mussels.
Media
Species Types
Scientific Name
Potamilus ohiensis
Description
This species enjoys the same geographic distribution in our state as the pink heelsplitter, and it generally resembles that species, too. But as the name suggests, the pink papershell usually has a thinner shell and is smaller. Also, it prefers rather shallow water with a good current.
Media
Species Types
Scientific Name
Epioblasma triquetra
Description
The snuffbox has been classified as endangered in Missouri and is a candidate for federal endangered status. Perhaps it should also be a candidate for a new common name, since the popularity of snuff-taking is long past.
Media
Species Types
Scientific Name
Faxonius longidigitus (formerly Orconectes longidigitus)
Description
The longpincered crayfish is large and colorful, with very long, slender, blue-green pincers that are studded with prominent yellowish knobs. It is restricted to the White River basin in the Ozarks.
Media
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
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
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
Species Types
Scientific Name
Faxonius macrus (formerly Orconectes macrus)
Description
The Neosho midget crayfish is a subdued mottled brown, with a prominent black band crossing the carapace near its junction with the abdomen. The pincers are broad and powerful. This small, stout crayfish is found in the Neosho stream drainage of southwestern Missouri and northwestern Arkansas.
Media
Species Types
Scientific Name
Faxonius williamsi (formerly Orconectes williamsi)
Description
Williams' crayfish is small and rather plain, without bright colors or bold markings. It has a pale, vase-shaped zone along the middle of the dark olive-tan carapace. It is found only in the upper White River drainage of Missouri and Arkansas.
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.