Trout is a generic common name for numerous species of carnivorous freshwater ray-finned fishes belonging to the genera oncorhynchus, salmo and salvelinus, all of which are members of the subfamily salmoninae in the family salmonidae. the word trout is also used for some similar-shaped but non-salmonid fish, such as the spotted seatrout/speckled trout (cynoscion nebulosus, which is actually a croaker). trout are closely related to salmon and have similar migratory life cycles. most trout are strictly potamodromous, spending their entire lives exclusively in freshwater lakes, rivers and wetlands and migrating upstream to spawn in the shallow gravel beds of smaller headwater creeks. the hat...

Source: Wikipedia