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 spothanded crayfish viewed from above on white background.

    Crayfishes

    About 36 species in Missouri
    Photo of a damselfly nymph on rocks in an aquarium.

    Damselfly Larvae

    Species in the suborder Zygoptera
    deertoe

    Deertoe

    Truncilla truncata
    Photo of a dragonfly larva resting on a stone.

    Dragonfly Larvae

    Species in the suborder Anisoptera
    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
    giant floater

    Giant Floater

    Pygandon grandis
    Photo of a giant water bug

    Giant Water Bugs

    Species in the genera Abedus, Belostoma, and Lethocerus
    Venomous Icon

    Venomous

    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 hellgrammite

    Hellgrammite

    Corydalus cornutus
    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
    lilliput

    Lilliput

    Toxolasma parvus
    maple leaf

    Mapleleaf

    Quadrula quadrula
    Photo of a mayfly naiad crawling on rock underwater

    Mayfly Larvae

    There are hundreds of species in North America.
    Photo of a gravid Mississippi grass shrimp in an aquarium.

    Mississippi Grass Shrimp

    Palaemonetes kadiakensis
    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
    Photo of a predaceous diving beetle

    Predaceous Diving Beetles (Water Tigers)

    Species in the beetle family Dytiscidae
    Photo of stonefly naiad on a rock underwater

    Stonefly Larvae

    There are hundreds of species in North America
    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.
    wabash pigtoe

    Wabash Pigtoe

    Fusconaia flava
    wartyback

    Wartyback

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

    Water Scavenger Beetles

    Beetles in the family Hydrophilidae
    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
    yellow sandshell

    Yellow Sandshell

    Lampsilis teres