Aquatic Invertebrates
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Scientific Name
Pygandon grandis
Description
When a floater dies, this large mussel with a thick shell will actually rise to the water surface and float as it decays.
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Toxolasma parvus
Description
These diminutive mollusks are the smallest of Missouri’s freshwater mussels.
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Elliptio dilatata
Description
Nacre color varies from purple to pink to white. In smaller rivers, the shell is much thinner.
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Scientific Name
Potamilus purpuratus
Description
Like the pink heelsplitter and fragile and pink papershells, the bluefer uses freshwater drum as a host.
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Scientific Name
Elliptio crassidens
Description
Today found only in the Meramec River, the elephantear has been classified as endangered in Missouri and is a candidate for federal endangered status.
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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.
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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.
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Scientific Name
Various species in the genus Hydra
Description
We’ve all seen aquariums and pictures of tropical saltwater invertebrates such as corals, jellyfish and anemones—but did you know that there are similar creatures living in the freshwater habitats of Missouri?
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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.
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Tubifex spp. and other aquatic tubificid annelids
Description
Tubificid worms, as a group, include the tubifex worms that aquarists feed to their pet fish. These segmented worms are related to earthworms and like them are detritus eaters.
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.