Photo of backswimmer, side view

    Backswimmers

    About 32 North American species in the family Notonectidae
    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
    giant floater

    Giant Floater

    Pygandon grandis
    No photo available

    Hydras

    Various species in the genus Hydra
    lilliput

    Lilliput

    Toxolasma parvus
    Southern redbelly dace male in spawning colors, side view photo with black background

    Minnows

    Notropis, Cyprinella, Hybognathus, Luxilus, and others
    pink heelsplitter

    Pink Heelsplitter

    Potamilus alatus
    plain pocketbook

    Plain Pocketbook

    Lampsilis cardium
    Rainbow trout side view photo with black background

    Rainbow Trout

    Oncorhynchus mykiss
    Photo of a ramshorn snail on a wet rock.

    Ramshorn Snails

    Gyraulus, Helisoma, Menetus, Micromenetus, Planorbula spp.
    Photo of an aquatic tubificid worm among rocks in an aquarium.

    Tubificid Worms (Tubifex Worms)

    Tubifex spp. and other aquatic tubificid annelids
    Photo of a pink planarian on a rock.

    Turbellarians (Planarians; Free-Living Flatworms)

    Species in genera Dugesia, Planaria, etc.
    Water springtails congregate in water above soggy dead leaves

    Water Springtail

    Podura aquatica