Octopodidae章魚科:Body muscilar. Mantle round, globular. Mantle opening moderate to wide. Fins absent. Arms moderate to long with well developed webs. Arm suckers usually in 2 rows and occasionally in a single row. Right Arm Ⅲ of males hectocotylized (rarely left Arm Ⅲ) with a spermatophore groove along dorsal side of the arm and the distal portion modified into copulatory organ.