Photo of backswimmer, side view

    Backswimmers

    About 32 North American species in the family Notonectidae
    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
    round pigtoe

    Round Pigtoe

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

    Virile Crayfish (Northern Crayfish)

    Faxonius virilis (formerly Oronectes virilis)