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
    No photo available

    Hydras

    Various species in the genus Hydra
    Photo of a midge fly larva crawling on a rock in an aquarium

    Midge Fly Larvae

    Nearly 1,100 species in North America
    Photo of a ramshorn snail on a wet rock.

    Ramshorn Snails

    Gyraulus, Helisoma, Menetus, Micromenetus, Planorbula spp.
    Photo of a pink planarian on a rock.

    Turbellarians (Planarians; Free-Living Flatworms)

    Species in genera Dugesia, Planaria, etc.