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

    Alderfly Larvae

    Sialis spp.
    Photo of a spotted fishing spider perched on the water's surface amid floating duckweed plants

    Aquatic Spiders

    Dolomedes spp., Tetragnatha spp., and others
    Photo of backswimmer, side view

    Backswimmers

    About 32 North American species in the family Notonectidae
    Black bullhead side view photo with black background

    Black Bullhead

    Ameiurus melas
    Bluegill male in spawning colors, side view photo with black background

    Bluegill

    Lepomis macrochirus
    Brook silverside side view photo with black background

    Brook Silverside

    Labidesthes sicculus
    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
    Common carp side view photo with black background

    Common Carp

    Cyprinus carpio
    invasive icon

    Invasive

    Photo of crane fly larva

    Crane Fly Larvae

    There are over 500 species of crane flies in North America.
    Cypress minnow side view photo with black background

    Cypress Minnow

    Hybognathus hayi
    exclamation mark

    Endangered

    Photo of a devil crayfish.

    Devil Crayfish

    Lacunicambarus aff. diogenes
    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
    Photo of several prosobranch pond snails crawling on a rock.

    Gilled Aquatic Snails (Prosobranch Pond Snails)

    Over 20 Missouri species in former subclass Prosobranchia
    Golden shiner male, side view photo with black background

    Golden Shiner

    Notemigonus crysoleucas
    Grass pickerel side view photo with black background

    Grass Pickerel

    Esox americanus
    Green sunfish male, side view photo with black background

    Green Sunfish

    Lepomis cyanellus
    Harlequin darter side view photo with black background

    Harlequin Darter

    Etheostoma histrio
    exclamation mark

    Endangered

    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
    Photo of pulmonate snail crawling on rock

    Lunged Aquatic Snails (Pulmonate Pond Snails)

    Over 30 Missouri species in former subclass Pulmonata
    Photo of a mayfly naiad crawling on rock underwater

    Mayfly Larvae

    There are hundreds of species in North America.
    Northern pike side view photo with black background

    Northern Pike

    Esox lucius
    paper pondshell

    Paper Pondshell (Paper Floater)

    Utterbackia imbecillis
    pond mussel

    Pond Mussel

    Ligumia subrostrata
    Photo of a ramshorn snail on a wet rock.

    Ramshorn Snails

    Gyraulus, Helisoma, Menetus, Micromenetus, Planorbula spp.
    River carpsucker side view photo with black background

    River Carpsucker

    Carpiodes carpio
    Photo of amphipod on a rock

    Scuds and Sideswimmers (Amphipods)

    Species in the crustacean order Amphipoda
    Spotted bass side view photo with black background

    Spotted Bass

    Micropterus punctulatus
    Photo of stonefly naiad on a rock underwater

    Stonefly Larvae

    There are hundreds of species in North America
    Taillight shiner male in spawning colors, side view photo with black background

    Taillight Shiner

    Notropis maculatus
    exclamation mark

    Endangered

    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 collared water scavenger beetle showing back.

    Water Scavenger Beetles

    Beetles in the family Hydrophilidae
    yellow sandshell

    Yellow Sandshell

    Lampsilis teres