The sharpnose sevengill shark (Heptranchias perlo), also known as one-finned shark, perlon shark, sevengill cow shark, sharpsnouted sevengill or slender sevengill, is a species of shark in the family Hexanchidae, and the only living species in the genus Heptranchias. Found almost circumglobally in deep water, it is one of the few species of sharks with seven pairs of gill slits as opposed to the usual five. The other shark species with seven gill slits is the broadnose sevengill shark. Though small, this shark is an active, voracious predator of invertebrates and fish. When caught, this species is notably defensive and will attempt to bite. It is of minor commercial importance. Taxonomy The genus name Heptranchias is from the Greek heptra meaning "seven arms", and agchein meaning "throttle", referring to this shark's seven pairs of gill slits. Other common names for this species include one-finned shark, perlon shark, sevengill cow shark, sevengilled Mediterranean shark, sevengilled shark, sharpnose seven-gill shark, snouted sevengill shark and slender sevengill shark. Some authors believe this species is distinct enough to merit its own family, Heptranchiidae. Distribution and habitat The sharpnose sevengill shark is uncommon, but widely distributed in the tropical and temperate regions of all oceans except for the northeastern Pacific Ocean. It is found from North Carolina to Cuba, including the northern Gulf of Mexico, and from Venezuela to Argentina in the western Atlantic. In the eastern Atlantic, it occurs from Morocco to Namibia, including the Mediterranean Sea. It is reported from the Indian Ocean off southwestern India, Aldabra Island, southern Mozambique, and South Africa. In the Pacific Ocean, it is known from Japan to China, Indonesia, Australia, New Zealand, and northern Chile. This is a demersal to semipelagic species usually captured at a depth of , but is occasionally found close to the surface (though these reports may represent misidentifications) or down to . It is mainly found on the outer continental shelf and upper continental slope, and may aggregate around seamounts. Description Usually measuring long, sharpnose sevengill sharks attain a maximum length of . This species has a slender, fusiform body with a narrow, pointed head. The eyes are very large and fluoresce green in live specimens. The mouth is narrow and strongly curved, containing 9-11 teeth on either side of the upper jaw and five teeth on either side of the lower. The upper teeth are narrow and hook-shaped with small lateral