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 spothanded crayfish viewed from above on white background.

    Crayfishes

    About 36 species in Missouri
    Photo of a gravid Mississippi grass shrimp in an aquarium.

    Mississippi Grass Shrimp

    Palaemonetes kadiakensis
    Photo of an Ohio shrimp with small grayish pincers in the foreground.

    Ohio Shrimp

    Macrobrachium ohione
    Photo of amphipod on a rock

    Scuds and Sideswimmers (Amphipods)

    Species in the crustacean order Amphipoda