Photo of a spotted fishing spider perched on the water's surface amid floating duckweed plants

    Aquatic Spiders

    Dolomedes spp., Tetragnatha spp., and others
    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
    Photo of two Chinese mystery snails, on a white background, with a ruler nearby for scale.

    Chinese Mystery Snail

    Cipangopaludina chinensis malleata (syn. Bellamya chinensis)
    invasive icon

    Invasive

    Photo of crane fly larva

    Crane Fly Larvae

    There are over 500 species of crane flies in North America.
    Photo of a spothanded crayfish viewed from above on white background.

    Crayfishes

    About 36 species in Missouri
    Photo of a devil crayfish.

    Devil Crayfish

    Lacunicambarus aff. diogenes
    Monkey Face Mussel

    Freshwater Mussels

    Bivalve molluscs in order Unionoida
    No photo available

    Hydras

    Various species in the genus Hydra
    Photo of a leech

    Leeches

    Various species in the subclass Hirudinea
    Photo of a midge fly larva crawling on a rock in an aquarium

    Midge Fly Larvae

    Nearly 1,100 species in North America
    pink papershell

    Pink Papershell

    Potamilus ohiensis
    Photo of a predaceous diving beetle

    Predaceous Diving Beetles (Water Tigers)

    Species in the beetle family Dytiscidae
    Photo of a ramshorn snail on a wet rock.

    Ramshorn Snails

    Gyraulus, Helisoma, Menetus, Micromenetus, Planorbula spp.
    Photo of stonefly naiad on a rock underwater

    Stonefly Larvae

    There are hundreds of species in North America
    Photo of a pink planarian on a rock.

    Turbellarians (Planarians; Free-Living Flatworms)

    Species in genera Dugesia, Planaria, etc.