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

    Bryozoans (Moss Animals)

    Freshwater species in the phylum Bryozoa
    butterfly

    Butterfly

    Ellipsaria lineolata
    Photo of a papershell crayfish, also called calico crayfish.

    Calico Crayfish (Papershell Crayfish)

    Faxonius immunis (formerly Orconectes immunis)
    Photo of a spothanded crayfish viewed from above on white background.

    Crayfishes

    About 36 species in Missouri
    Photo of a devil crayfish.

    Devil Crayfish

    Lacunicambarus aff. diogenes
    elktoe

    Elktoe

    Alasmidonta marginata
    fatmucket

    Fatmucket

    Lampsilis siliquoidea
    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
    giant floater

    Giant Floater

    Pygandon grandis
    Photo of hellgrammite

    Hellgrammite

    Corydalus cornutus
    Photo of a horsehair worm in an aquarium

    Horsehair Worms

    About 350 species scientifically described.
    Photo of a leech

    Leeches

    Various species in the subclass Hirudinea
    maple leaf

    Mapleleaf

    Quadrula quadrula
    mucket

    Mucket

    Actinonaias ligamentina
    paper pondshell

    Paper Pondshell (Paper Floater)

    Utterbackia imbecillis
    pimpleback

    Pimpleback

    Quadrula pustulosa
    pink heelsplitter

    Pink Heelsplitter

    Potamilus alatus
    pink papershell

    Pink Papershell

    Potamilus ohiensis
    pistolgrip

    Pistolgrip (Buckhorn)

    Tritogonia verrucosa
    plain pocketbook

    Plain Pocketbook

    Lampsilis cardium
    pond mussel

    Pond Mussel

    Ligumia subrostrata
    Photograph of Purple Wartyback freshwater mussel shell exterior view
    round pigtoe

    Round Pigtoe

    Pleurobema sintoxia
    Spectaclecase

    Spectaclecase

    Cumberlandia monodonta
    spike

    Spike (Ladyfinger)

    Elliptio dilatata
    threehorn wartyback

    Threehorn Wartyback

    Obliquaria reflexa
    threeridge

    Threeridge

    Amblema plicata
    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)
    wabash pigtoe

    Wabash Pigtoe

    Fusconaia flava
    wartyback

    Wartyback

    Quadrula nodulata
    Photo of a water nymph crayfish, side view of specimen carefully arranged against black background

    Water Nymph Crayfish

    Faxonius nais (formerly Orconectes nais)
    Photo of a water scorpion, genus Ranatra, captured in a jar of pond water.

    Water Scorpions

    Ranatra spp. and Nepa apiculata
    white heelsplitter

    White Heelsplitter

    Lasmigona complanata
    Photo of a White River crawfish.

    White River Crawfish

    Procambarus acutus
    yellow sandshell

    Yellow Sandshell

    Lampsilis teres