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 a belted crayfish, also called Big River crayfish.

    Belted Crayfish (Big River Crayfish)

    Faxonius harrisonii (formerly Orconectes harrisonii)
    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
    Photograph of Ebonyshell freshwater mussel shell exterior view

    Ebonyshell

    Fusconaia ebena
    exclamation mark

    Endangered

    elephant's ear

    Elephantear

    Elliptio crassidens
    exclamation mark

    Endangered

    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
    lilliput

    Lilliput

    Toxolasma parvus
    Photo of a longpincered crayfish.

    Longpincered Crayfish

    Faxonius longidigitus (formerly Orconectes longidigitus)
    Photo of pulmonate snail crawling on rock

    Lunged Aquatic Snails (Pulmonate Pond Snails)

    Over 30 Missouri species in former subclass Pulmonata
    Photograph of several mosquito larvae resting at water surface

    Mosquito Larvae

    There are about 50 species of mosquitoes in our state.
    pistolgrip

    Pistolgrip (Buckhorn)

    Tritogonia verrucosa
    pond mussel

    Pond Mussel

    Ligumia subrostrata
    Photo of a predaceous diving beetle

    Predaceous Diving Beetles (Water Tigers)

    Species in the beetle family Dytiscidae
    Photo of a ramshorn snail on a wet rock.

    Ramshorn Snails

    Gyraulus, Helisoma, Menetus, Micromenetus, Planorbula spp.
    Photo of a ringed crayfish.

    Ringed Crayfish

    Faxonius neglectus (formerly Orconectes neglectus)
    Photo of a saddleback crayfish.

    Saddleback Crayfish

    Faxonius medius (formerly Orconectes medius)
    Spectaclecase

    Spectaclecase

    Cumberlandia monodonta
    spike

    Spike (Ladyfinger)

    Elliptio dilatata
    Photo of a spothanded crayfish viewed through creekwater.

    Spothanded Crayfish

    Faxonius punctimanus (formerly Orconectes punctimanus)
    Photo of a St. Francis River crayfish.

    St. Francis River Crayfish

    Faxonius quadruncus (formerly Orconectes quadruncus)
    Photo of stonefly naiad on a rock underwater

    Stonefly Larvae

    There are hundreds of species in North America
    threeridge

    Threeridge

    Amblema plicata
    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
    Photo of two water penny beetles clinging to a wet rock.

    Water Penny Beetle Larvae

    Beetles in the family Psephenidae
    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
    Photo of a single water strider

    Water Striders

    Aquarius remigis; also species in the genus Gerris
    Photo of a whirligig beetle viewed from above

    Whirligig Beetles

    Species in the beetle family Gyrinidae
    Photo of a woodland crayfish.

    Woodland Crayfish

    Faxonius hylas (formerly Orconectes hylas)