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

    Photo of a spothanded crayfish viewed from above on white background.

    Crayfishes

    About 36 species in Missouri
    Photo of a dragonfly larva resting on a stone.

    Dragonfly Larvae

    Species in the suborder Anisoptera
    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)
    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 horsehair worm in an aquarium

    Horsehair Worms

    About 350 species scientifically described.
    No photo available

    Hydras

    Various species in the genus Hydra
    Photo of a leech

    Leeches

    Various species in the subclass Hirudinea
    lilliput

    Lilliput

    Toxolasma parvus
    maple leaf

    Mapleleaf

    Quadrula quadrula
    Photo of a gravid Mississippi grass shrimp in an aquarium.

    Mississippi Grass Shrimp

    Palaemonetes kadiakensis
    paper pondshell

    Paper Pondshell (Paper Floater)

    Utterbackia imbecillis
    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
    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)
    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