OCTOPODIDAE

＊Nearly 40 species of octopods have been reported from Japanese waters among which only 4 species are included in this key.
No species identification is possible useing this key. A more compere hensive key may be offered with additional reference collections in the future.

　　Rostral tip flat; wing shoulder strongly projected; lateral wall 3 times hood length
---Octopus vulgalis
　

　Rostral tip uneven; wing shoulder weakly projected; lateral wall 2.5 times hood length
---Bathypolypus selebrosus
　

　Rostral tip roundly pointed; wing shoulder projected anterioly; lateral wall 2.5 times of hood length
---Benthoctopus profundorum
　

　Rostral tip roundly pointed; wing shoulder weakly projected anteriorly; lateral wall 2.2 times of hood length
---Octopus conispadeceus
　　