Photo of an alderfly larva among rocks and gravel in an aquarium.

    Alderfly Larvae

    Sialis spp.
    Photo of an aquatic isopod in an aquarium, crawling on a rock.

    Aquatic Pillbugs and Sowbugs (Aquatic Isopods)

    Freshwater members of the crustacean order Isopoda
    Photo of a spotted fishing spider perched on the water's surface amid floating duckweed plants

    Aquatic Spiders

    Dolomedes spp., Tetragnatha spp., and others
    Image of a bigmouth buffalo

    Bigmouth Buffalo

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

    Bryozoans (Moss Animals)

    Freshwater species in the phylum Bryozoa
    Photo of caddisfly larva with case made of detritus

    Caddisfly Larvae

    Various species in the order Trichoptera
    Photo of a papershell crayfish, also called calico crayfish.

    Calico Crayfish (Papershell Crayfish)

    Faxonius immunis (formerly Orconectes immunis)
    channel catfish

    Channel Catfish

    Ictalurus punctatus
    Photo of crane fly larva

    Crane Fly Larvae

    There are over 500 species of crane flies in North America.
    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
    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)
    Image of a freshwater drum fish

    Freshwater Drum

    Aplodinotus grunniens
    Photo of a freshwater jellyfish

    Freshwater Jellyfish

    Craspedacusta sowerbii (syn. C. sowerbyi)
    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
    Image of a golden redhorse fish

    Golden Redhorse

    Moxostoma erythrurum
    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
    Photo of pulmonate snail crawling on rock

    Lunged Aquatic Snails (Pulmonate Pond Snails)

    Over 30 Missouri species in former subclass Pulmonata
    Photo of a midge fly larva crawling on a rock in an aquarium

    Midge Fly Larvae

    Nearly 1,100 species in North America
    Photograph of several mosquito larvae resting at water surface

    Mosquito Larvae

    There are about 50 species of mosquitoes in our state.
    Illustration of a northern pike

    Northern Pike

    Esox lucius
    Photo of a ramshorn snail on a wet rock.

    Ramshorn Snails

    Gyraulus, Helisoma, Menetus, Micromenetus, Planorbula spp.
    Image of a river carpsucker

    River Carpsucker

    Carpiodes carpio
    Image of a silver carp

    Silver Carp

    Hypophthalmichthys molitrix
    invasive icon

    Invasive

    Illustration of northern snakehead, viewed from side

    Snakeheads

    Channa spp. and Parachanna spp., including C. argus
    invasive icon

    Invasive

    Photo of stonefly naiad on a rock underwater

    Stonefly Larvae

    There are hundreds of species in North America
    Photo of an aquatic tubificid worm among rocks in an aquarium.

    Tubificid Worms (Tubifex Worms)

    Tubifex spp. and other aquatic tubificid annelids
    Photo of a pink planarian on a rock.

    Turbellarians (Planarians; Free-Living Flatworms)

    Species in genera Dugesia, Planaria, etc.
    Photo of a water boatman

    Water Boatmen

    About 125 species in North America in the family Corixidae
    Water springtails congregate in water above soggy dead leaves

    Water Springtail

    Podura aquatica
    Image of a mosquitofish

    Western Mosquitofish

    Gambusia affinis
    Photo of a whirligig beetle viewed from above

    Whirligig Beetles

    Species in the beetle family Gyrinidae
    Image of white bass

    White Bass

    Morone chrysops
    Photo of a White River crawfish.

    White River Crawfish

    Procambarus acutus