Callistoctopus rapanuiCallistoctopus rapanui, or the rapanui octopus, is the only endemic octopus species in Rapa Nui. It was first described by Gilbert L. Voss in 1979 as Octopus rapanui.DescriptionCallistoctopus rapanui is large and muscular, with a mantle length of up to and a total length of up to. It has scattered rough tubercles across the body. The arms are 3.5 to 4.5 times the length of the mantle, and have two rows of suckers each. C. rapanui is cream-gray with a darker purple hue on its dorsal surfaces. Its most distinctive feature is a "straight, out-turned" rostrum.DistributionCallistoctopus rapanui is subtropical and only known in Rapa Nui. It is benthic, and found at depths of.Use by humansCallistoctopus rapanui are fished for food in Rapa Nui, and make up 0.6% of subsistence fishing catch.