A new intertidal octopus species, Octopus incella (Cephalopoda: Octopodidae), from Okinawa, southern Japan

Abstract

A new Octopus species, Octopus incella sp. nov., was found on a shallow coral beach on Okinawa Island, in the tropical waters of Japan. This species possesses the following characteristics: small size (28.2–31.0 mm mantle length [ML]), robust body with medium and approximately equivalent length (3.4–4.6 × ML) arms, relatively large normal suckers without abruptly enlarged suckers, shallow arm webs, lack of primary papillae on dorsal surface and above eyes, absence of white dorsal spots, low number of gill lamellae (5–6 per demibranch), V shaped terminal organ with well-developed diverticulum. This octopus lives in small holes in boulders or dead corals on the beach, where it is completely exposed during low tide. The generic status of this species is discussed.