Photo of backswimmer, side view

    Backswimmers

    About 32 North American species in the family Notonectidae
    Photo of a spothanded crayfish viewed from above on white background.

    Crayfishes

    About 36 species in Missouri
    Monkey Face Mussel

    Freshwater Mussels

    Bivalve molluscs in order Unionoida
    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
    Photo of a ramshorn snail on a wet rock.

    Ramshorn Snails

    Gyraulus, Helisoma, Menetus, Micromenetus, Planorbula spp.
    Redfin darter side view photo with black background

    Redfin Darter

    Etheostoma whipplei
    exclamation mark

    Endangered

    Southern redbelly dace side view photo with black background

    Southern Redbelly Dace

    Phoxinus erythrogaster
    Photo of a northern, also called virile, crayfish.

    Virile Crayfish (Northern Crayfish)

    Faxonius virilis (formerly Oronectes virilis)