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

    Bryozoans (Moss Animals)

    Freshwater species in the phylum Bryozoa
    Photo of two Chinese mystery snails, on a white background, with a ruler nearby for scale.

    Chinese Mystery Snail

    Cipangopaludina chinensis malleata (syn. Bellamya chinensis)
    invasive icon

    Invasive

    Monkey Face Mussel

    Freshwater Mussels

    Bivalve molluscs in order Unionoida
    No photo available

    Hydras

    Various species in the genus Hydra
    lilliput

    Lilliput

    Toxolasma parvus
    pink papershell

    Pink Papershell

    Potamilus ohiensis
    Photo of a pink planarian on a rock.

    Turbellarians (Planarians; Free-Living Flatworms)

    Species in genera Dugesia, Planaria, etc.
    Photo of a northern, also called virile, crayfish.

    Virile Crayfish (Northern Crayfish)

    Faxonius virilis (formerly Oronectes virilis)
    Photo of a water nymph crayfish, side view of specimen carefully arranged against black background

    Water Nymph Crayfish

    Faxonius nais (formerly Orconectes nais)