Cutbow

The cutbow (Oncorhynchus sp. × mykiss) is an interspecific fertile hybrid between rainbow trout (Oncorhynchus mykiss) and cutthroat trout (Oncorhynchus sp.). Based on currently accepted taxonomy, four species-specific hybrid names are recognized for cutbow:

• Coastal cutthroat trout × rainbow trout (Oncorhynchus clarkii × mykiss), or coastal cutbow
• Westslope cutthroat trout × rainbow trout (Oncorhynchus lewisi × mykiss), or westlope cutbow
• Lahontan cutthroat trout × rainbow trout (Oncorhynchus henshawii × mykiss), or Lahontan cutbow
• Rocky Mountain cutthroat trout × rainbow trout (Oncorhynchus virginalis × mykiss), or Rocky Mountain cutbow

Of these four species-specific hybrids, only coastal and westslope cutbow have natural range overlap; Lahontan and Rocky Mountain cutbow are the result of rainbow trout stocking and invasion. Due to these introductions, many populations of cutthroat trout are at risk of genetic pollution. Significant management intervention at state and federal levels has occurred to preserve native populations of cutthroat trout.