Gray, speckled, translucent gelatinous blob cut in half to show structure

    Bryozoans (Moss Animals)

    Freshwater species in the phylum Bryozoa
    butterfly

    Butterfly

    Ellipsaria lineolata
    elktoe

    Elktoe

    Alasmidonta marginata
    Photo of a fishfly larva crawling among rocks in an aquarium.

    Fishfly Larvae

    Chauliodes, Neohermes, and Nigronia spp. (in eastern US)
    fragile papershell

    Fragile Papershell

    Leptodea fragilis
    Monkey Face Mussel

    Freshwater Mussels

    Bivalve molluscs in order Unionoida
    Photo of a horsehair worm in an aquarium

    Horsehair Worms

    About 350 species scientifically described.
    maple leaf

    Mapleleaf

    Quadrula quadrula
    mucket

    Mucket

    Actinonaias ligamentina
    paper pondshell

    Paper Pondshell (Paper Floater)

    Utterbackia imbecillis
    pimpleback

    Pimpleback

    Quadrula pustulosa
    pink mucket

    Pink Mucket

    Lampsilis abrupta
    exclamation mark

    Endangered

    plain pocketbook

    Plain Pocketbook

    Lampsilis cardium
    threeridge

    Threeridge

    Amblema plicata
    Photo of a pink planarian on a rock.

    Turbellarians (Planarians; Free-Living Flatworms)

    Species in genera Dugesia, Planaria, etc.
    wabash pigtoe

    Wabash Pigtoe

    Fusconaia flava
    wartyback

    Wartyback

    Quadrula nodulata
    yellow sandshell

    Yellow Sandshell

    Lampsilis teres