Trout are species of freshwater fish belonging to the genera Oncorhynchus, Salmo and Salvelinus, all of which are of the subfamily Salmoninae of the family Salmonidae. The word trout is also used as part of the name of some non-salmonid fish such as Cynoscion nebulosus, the spotted seatrout or speckled trout. Trout are closely related to salmon and char (or charr): species termed salmon and char occur in the same genera as do fish called trout (Oncorhynchus – Pacific salmon and trout, Salmo – Atlantic salmon and various trout, Salvelinus – char and trout). Lake trout and most other trout live in freshwater lakes and rivers exclusively, while there are others, such as the steelhead, a form of the coastal rainbow trout, that can spend two or three years at sea before returning to fresh water to spawn (a habit more typical of salmon). Arctic char and brook trout are part of the char genus. Trout are an important food source for humans and wildlife, including brown bears, birds of prey such as eagles, and other animals. They are classified as oily fish. Species The name "trout" is commonly used for many (if not most) species in three of the seven genera in the subfamily Salmoninae: Salmo (Atlantic), Oncorhynchus (Pacific) and Salvelinus (circum-arctic). Fish species referred to as trout include: Genus Salmo, all extant species except Atlantic salmon Adriatic trout, Salmo obtusirostris Brown trout, Salmo trutta River trout, S. t. morpha fario Lake trout/Lacustrine trout, S. t. morpha lacustris Sea trout, S. t. morpha trutta Flathead trout, Salmo platycephalus Marble trout, Soca River trout or Soča trout – Salmo marmoratus Ohrid trout, Salmo letnica, S. balcanicus (extinct), S. lumi, and S. aphelios Sevan trout, Salmo ischchan Genus Oncorhynchus, six of the 12 extant species Apache trout, Oncorhynchus apache Biwa trout, Oncorhynchus masou rhodurus Cutthroat trout, Oncorhynchus clarki Coastal cutthroat trout, O. c. clarki Crescenti trout, O. c. c. f. crescenti Alvord cutthroat trout, O. c. alvordensis (extinct) Bonneville cutthroat trout, O. c. utah Humboldt cutthroat trout, O. c. humboldtensis Lahontan cutthroat trout, O. c. henshawi Whitehorse Basin cutthroat trout Paiute cutthroat trout, O. c. seleniris Snake River fine-spotted cutthroat trout, O. c. behnkei Westslope cutthroat trout, O. c. lewisi Yellowfin cutthroat trout, O. c. macdonaldi (extinct) Yellowstone cutthroat trout, O. c. bouvieri Colorado River cutthroat trout, O. c. pleuriticus Greenback cutthroat trout, O. c. stomias Rio Grande cutthroat trout, O.