Gray, speckled, translucent gelatinous blob cut in half to show structure

    Bryozoans (Moss Animals)

    Freshwater species in the phylum Bryozoa
    Orangethroat darter male in spawning colors, side view photo with black background

    Darters

    Etheostoma, Percina, Ammocrypta, and Crystallaria spp.
    Monkey Face Mussel

    Freshwater Mussels

    Bivalve molluscs in order Unionoida
    Greenside darter female, side view photo with black background

    Greenside Darter

    Etheostoma blennioides
    No photo available

    Hydras

    Various species in the genus Hydra
    Southern redbelly dace male in spawning colors, side view photo with black background

    Minnows

    Notropis, Cyprinella, Hybognathus, Luxilus, and others
    Niangua darter female, side view photo with black background

    Niangua Darter

    Etheostoma nianguae
    exclamation mark

    Endangered

    Photo of a ringed crayfish.

    Ringed Crayfish

    Faxonius neglectus (formerly Orconectes neglectus)
    Photo of a pink planarian on a rock.

    Turbellarians (Planarians; Free-Living Flatworms)

    Species in genera Dugesia, Planaria, etc.
    Photo of a northern, also called virile, crayfish.

    Virile Crayfish (Northern Crayfish)

    Faxonius virilis (formerly Oronectes virilis)