Uku is commonly known as the Hawaii blue-green snapper. This fish shares many of the same qualities that have given opakapaka and onaga their reputations as outstanding table fish. Like other Hawaii snappers, uku has clear, translucent pink flesh that is delicately flavored, moist, and firm. Uku is blue-green in color on the upper third of its body, fading to grey-white on the lower two-thirds. Uku have long slender bodies with a deeply forked tail. They have a heavy bony head with a distinct horizontal groove in front of the eye and large canine looking teeth. They are one of the most popular deep-sea bottomfish harvested in Hawaii by landed weight. Uku reach sexual maturity at about 16 to18 inches in length, or four years old. Like many other bottomfish, Uku reach peak spawning in the summer months, but spawn a little earlier, beginning in May and peaking in June. By November, most Uku have completed spawning. Their pelagic eggs are released into the water column. The pelagic larvae float in the ocean for about 25 days until they move to deeper water before settling down on the ocean floor where they will spend the remainder of their adult life. Adult Uku inhabit open waters of deep lagoons, channels or seaward reefs. They are primarily solitary except when spawning in groups. They feed mainly on fishes, but also shrimps, crabs, cephalopods and planktonic organisms.