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

    Alderfly Larvae

    Sialis spp.
    Closeup of alligator gar held in a person's hands prior to being released into water

    Alligator Gar

    Atractosteus spatula (formerly Lepisosteus spatula)
    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
    Photo of backswimmer, side view

    Backswimmers

    About 32 North American species in the family Notonectidae
    Image of a blackspotted topminnow

    Blackspotted Topminnow

    Fundulus olivaceus
    Image of a blackstripe topminnow

    Blackstripe Topminnow

    Fundulus notatus
    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
    Color illustration of Central Mudminnow

    Central Mudminnow

    Umbra limi
    exclamation mark

    Endangered

    channel catfish

    Channel Catfish

    Ictalurus punctatus
    Image of a chestnut lamprey

    Chestnut Lamprey

    Ichthyomyzon castaneus
    Illustration of common carp

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

    Crayfishes

    About 36 species in Missouri
    Color illustration of Crystal Darter

    Crystal Darter

    Crystallaria asprella
    exclamation mark

    Endangered

    Photo of a damselfly nymph on rocks in an aquarium.

    Damselfly Larvae

    Species in the suborder Zygoptera
    deertoe

    Deertoe

    Truncilla truncata
    Photo of a devil crayfish.

    Devil Crayfish

    Lacunicambarus aff. diogenes
    Photo of a dragonfly larva resting on a stone.

    Dragonfly Larvae

    Species in the suborder Anisoptera
    Photograph of Ebonyshell freshwater mussel shell exterior view

    Ebonyshell

    Fusconaia ebena
    exclamation mark

    Endangered

    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)
    Illustration of an adult flathead catfish

    Flathead Catfish

    Pylodictis olivaris
    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 a gray-speckled crayfish.

    Gray-Speckled Crayfish

    Faxonius palmeri (formerly Orconectes palmeri)
    Color illustration of Harlequin Darter-Male

    Harlequin Darter

    Etheostoma histrio
    exclamation mark

    Endangered

    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
    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
    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 midge fly larva crawling on a rock in an aquarium

    Midge Fly Larvae

    Nearly 1,100 species in North America
    Photo of a gravid Mississippi grass shrimp in an aquarium.

    Mississippi Grass Shrimp

    Palaemonetes kadiakensis
    Photograph of several mosquito larvae resting at water surface

    Mosquito Larvae

    There are about 50 species of mosquitoes in our state.
    Color illustration of Mountain Madtom

    Mountain Madtom

    Noturus eleutherus
    exclamation mark

    Endangered

    mucket

    Mucket

    Actinonaias ligamentina
    Photo of an Ohio shrimp with small grayish pincers in the foreground.

    Ohio Shrimp

    Macrobrachium ohione
    Photo of a paintedhand mudbug carefully arranged against a black background

    Paintedhand Mudbug

    Lacunicambarus polychromatus
    pimpleback

    Pimpleback

    Quadrula pustulosa
    pink mucket

    Pink Mucket

    Lampsilis abrupta
    exclamation mark

    Endangered

    pink papershell

    Pink Papershell

    Potamilus ohiensis
    plain pocketbook

    Plain Pocketbook

    Lampsilis cardium

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