This medium-sized fish, up to 18 inches, gets it’s name by the shape of it’s tail. It is bluish-purple in color and can be found near reefs and kelp beds from the shallows to a depth of 130 feet. We have seen them numerous times swimming under floating kelp paddies. It ranges from Vancouver Island to the Gulf of California, but is most abundant in Southern California and Baja California waters. Halfmoons will eat small invertebrates as well as algae. In turn, Halfmoons are preyed upon by seals, sea lions and numerous birds.