Blue rockfish are a very deep bodied fish with large pectoral fins. They have blue-black or grey-blue body color with heavy mottling of dark grey or black. Two stripes run down and back from the eye, with vague striping on the forehead. They are lighter ventrally. Blue rockfish resemble black rockfish after capture and when viewed underwater. They are distinguished by having a more oval body shape than black rockfish, a smaller mouth, and being mottled, particularly over the head.