Pacifastacus leniusculus (Columbia River Signal Crayfish) is a species of decapods in the family freshwater crayfishes. It is associated with freshwater habitat. It is native to United States and Canada.
Definition: An aquatic biome that comprises systems of open-ocean and unprotected coastal habitats, characterized by exposure to wave action, tidal fluctuation, and ocean currents as well as systems that largely resemble these. Water in the marine biome is generally within the salinity range of seawater: 30 to 38 ppt.