The following list of known freshwater fish species, subspecies, and hybrids occurring in Washington state is taken from Wydoski and Whitney(2003). Some scientific names have been updated or corrected. Trout nomenclature follows Behnke et al.(2002). Asterisks denote introduced fishes. The list includes several anadromous species, and two normally marine species (starry flounder and shiner perch) that are occasionally found in freshwater. Only one species (Olympic mudminnow) is a Washington endemic, however three others (Nooksack dace, Salish sucker, and margined sculpin) have very limited distributions outside the state. Sixty-seven fish species, subspecies, or hybrids are listed, 37 native, and 30 introduced.

Petromyzontiformes

Family Petromyzontidae

Acipenseriformes

Family Acipenseridae

Clupeiformes

Family Clupeidae

Cypriniformes

Family Catostomidae

Family Cobitidae

Family Cyprinidae

Cyprinodontiformes

Family Fundulidae

Family Poeciliidae

Esociformes

Family Esocidae

Perciformes

Family Centrarchidae

Family Embiotocidae

Family Percidae

Family Moronidae

Percopsiformes

Family Percopsidae

Gadiformes

Family Gadidae

Gasterosteiformes

Family Gasterosteidae

Osmeriformes

Family Osmeridae

Pleuronectiformes

Family Pleuronectidae

Salmoniformes

Family Salmonidae

Scorpaeniformes

Family Cottidae

Siluriformes

Family Ictaluridae