Photo of backswimmer, side view

    Backswimmers

    About 32 North American species in the family Notonectidae
    Image of a creek chub

    Creek Chub

    Semotilus atromaculatus
    ellipse

    Ellipse and Bleedingtooth

    Venustaconcha ellipsiformis and V. pleasii
    Monkey Face Mussel

    Freshwater Mussels

    Bivalve molluscs in order Unionoida
    Photo of a midge fly larva crawling on a rock in an aquarium

    Midge Fly Larvae

    Nearly 1,100 species in North America
    Illustration of an orangethroat darter

    Orangethroat Darter

    Etheostoma spectabile
    round pigtoe

    Round Pigtoe

    Pleurobema sintoxia
    Photo of a northern, also called virile, crayfish.

    Virile Crayfish (Northern Crayfish)

    Faxonius virilis (formerly Oronectes virilis)