Are steelhead (rainbow trout) trout or salmon?
Until 1988, steelhead (the anadromous form of rainbow trout) was classified in the genus Salmo along with Atlantic salmon, brown trout, and several western trout species. With additional osteology and biochemistry data, biologists have now reclassified steelhead as members of the genus Oncorhynchus. The reason for this is that new information suggested that steelhead are more closely related to Pacific salmon than to brown trout and Atlantic salmon. As such, the American Fisheries Society - American Society of Ichthyologists Committee on Names of Fishes voted unanimously to accept Oncorhynchus as the proper generic name. As such, the scientific name of steelhead was changed from Salmo gairdneri to Oncorhynchus mykiss. The generic names of the golden, Mexican golden, Gila, and Apache trouts were also changed to Oncorhynchus. Since all of these western trouts including steelhead are biologically capable of repeat spawning and do not die after spawning, it has been suggested this group be called the Pacific trout.