GRAY UNICORNFISH
Naso caesius Randall & Bell, 1992
     The same size, shape and color as the more common Sleek Unicornfish with which it may school, this fish varies from dark brown to bluish gray. Occasionally it "turns on" a pattern of vertically elongated spots—the only easy means of identifying it underwater. The species was not described and named until 1992, unusual for a fish of its size and wide distribution. Genetic studies confirm that it is reproductively isolated from N. hexacanthus. To about 2 ft. Islands of the Pacific. Photo: Molokini Islet, Maui. 10 ft. (The somewhat similar Spotted Unicornfish, Naso maculatus, has many small dark brown spots. In the main Hawaiian Islands it occurs only below sport diving depths; in the northwestern chain it enters shallower water and can be seen by divers.)