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

    Alderfly Larvae

    Sialis spp.
    brokenray

    Arkansas Brokenray

    Lampsilis reeveiana
    Photo of a bristly cave crayfish, viewed from the side.

    Bristly Cave Crayfish

    Cambarus setosus
    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 coldwater crayfish.

    Coldwater Crayfish

    Faxonius eupunctus (formerly Orconectes eupunctus)
    exclamation mark

    Endangered

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

    Crayfishes

    About 36 species in Missouri
    deertoe

    Deertoe

    Truncilla truncata
    elephant's ear

    Elephantear

    Elliptio crassidens
    exclamation mark

    Endangered

    elktoe

    Elktoe

    Alasmidonta marginata
    ellipse

    Ellipse and Bleedingtooth

    Venustaconcha ellipsiformis and V. pleasii
    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 several prosobranch pond snails crawling on a rock.

    Gilled Aquatic Snails (Prosobranch Pond Snails)

    Over 20 Missouri species in former subclass Prosobranchia
    Photo of Hubbs' crayfish.

    Hubbs’ Crayfish

    Cambarus hubbsi
    No photo available

    Hydras

    Various species in the genus Hydra
    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
    Photo of a Mammoth Spring crayfish.

    Mammoth Spring Crayfish

    Faxonius marchandi (formerly Orconectes marchandi)
    Meek's Crayfish

    Meek’s Crayfish

    Faxonius meeki (formerly Orconectes meeki)
    Photo of an Ozark crayfish.

    Ozark Crayfish

    Faxonius ozarkae (formerly Orconectes ozarkae)
    pimpleback

    Pimpleback

    Quadrula pustulosa
    pink mucket

    Pink Mucket

    Lampsilis abrupta
    exclamation mark

    Endangered

    plain pocketbook

    Plain Pocketbook

    Lampsilis cardium
    Photograph of Purple Wartyback freshwater mussel shell exterior view
    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)
    round pigtoe

    Round Pigtoe

    Pleurobema sintoxia
    Photo of a saddleback crayfish.

    Saddleback Crayfish

    Faxonius medius (formerly Orconectes medius)
    Photo of amphipod on a rock

    Scuds and Sideswimmers (Amphipods)

    Species in the crustacean order Amphipoda
    Photograph of Sheepnose freshwater mussel shell exterior view

    Sheepnose (Bullhead)

    Plethobasus cyphyus
    exclamation mark

    Endangered

    Photo of a spothanded crayfish viewed through creekwater.

    Spothanded Crayfish

    Faxonius punctimanus (formerly Orconectes punctimanus)
    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 northern, also called virile, crayfish.

    Virile Crayfish (Northern Crayfish)

    Faxonius virilis (formerly Oronectes virilis)
    wabash pigtoe

    Wabash Pigtoe

    Fusconaia flava
    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
    Water springtails congregate in water above soggy dead leaves

    Water Springtail

    Podura aquatica
    Photo of Williams' crayfish.

    Williams’ Crayfish

    Faxonius williamsi (formerly Orconectes williamsi)
    Photo of a woodland crayfish.

    Woodland Crayfish

    Faxonius hylas (formerly Orconectes hylas)