The brown is a native of Europe; several strains of brown trout have become established here in the United States and they are our most common salmonid. The Brown Trout is the Carp of the coldwater streams, having dominated almost every ecosystem they have invaded. These exotic fish have thrived in many streams rendered inhospitable to native brook trout by siltation, pollution, and damming. The typical brown trout is about a foot long and half a pound, although stream browns up to 31 inches long have been caught, and some migratory strains exceed even this. They are highly voracious predators, especially once they reach adult size. Browns are buttery-yellow or yellowish-brown in color, and covered in black and red spots of varying sizes.