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

    Bryozoans (Moss Animals)

    Freshwater species in the phylum Bryozoa
    butterfly

    Butterfly

    Ellipsaria lineolata
    deertoe

    Deertoe

    Truncilla truncata
    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 several prosobranch pond snails crawling on a rock.

    Gilled Aquatic Snails (Prosobranch Pond Snails)

    Over 20 Missouri species in former subclass Prosobranchia
    Photo of a deer fly larva, probably in a petri dish, on a gray background.

    Horse and Deer Fly Larvae

    Tabanus, Chrysops, and related genera
    Photo of a horsehair worm in an aquarium

    Horsehair Worms

    About 350 species scientifically described.
    No photo available

    Hydras

    Various species in the genus Hydra
    maple leaf

    Mapleleaf

    Quadrula quadrula
    Photo of a mayfly naiad crawling on rock underwater

    Mayfly Larvae

    There are hundreds of species in North America.
    mucket

    Mucket

    Actinonaias ligamentina
    pimpleback

    Pimpleback

    Quadrula pustulosa
    pink mucket

    Pink Mucket

    Lampsilis abrupta
    exclamation mark

    Endangered

    plain pocketbook

    Plain Pocketbook

    Lampsilis cardium
    Photo of stonefly naiad on a rock underwater

    Stonefly Larvae

    There are hundreds of species in North America
    threeridge

    Threeridge

    Amblema plicata
    Photo of a pink planarian on a rock.

    Turbellarians (Planarians; Free-Living Flatworms)

    Species in genera Dugesia, Planaria, etc.
    wartyback

    Wartyback

    Quadrula nodulata
    Photo of a collared water scavenger beetle showing back.

    Water Scavenger Beetles

    Beetles in the family Hydrophilidae
    yellow sandshell

    Yellow Sandshell

    Lampsilis teres