''Sasakiopus'' is a genus of

octopus An octopus ( : octopuses or octopodes, see below for variants) is a soft-bodied, eight- limbed mollusc of the order Octopoda (, ). The order consists of some 300 species and is grouped within the class Cephalopoda with squids, cuttle ...

containing only one species, ''Sasakiopus salebrosus'', the rough octopus. It is part of the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Enteroctopodidae Enteroctopodidae is a small family of octopuses. This family was formerly considered a subfamily of the family Octopodidae ''sensu lato ''Sensu'' is a Latin word meaning "in the sense of". It is used in a number of fields including biology, ...

. Genetic analysis appeared to show that ''S. salebrosus'' is the sister taxon of the genera '' Benthoctopus'' and '' Vulcanoctopus'', although the former is now considered a

synonym A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all ...

of '' Bathypolypus'', the only genus in the family

Bathypolypodidae ''Bathypolypus'' is a genus of octopuses in the monotypic family Bathypolypodidae. It has five described species. Species Species in the genus ''Bathypolypus'' include: * '' Bathypolypus arcticus'' ( Prosch, 1847) ** '' Bathypolypus arcticus arc ...

, and the latter as a synonym of '' Muusoctopus''. The

type specimen In biology, a type is a particular wiktionary:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to a ...

was collected and the

Sea of Okhotsk The Sea of Okhotsk ( rus, Охо́тское мо́ре, Ohótskoye móre ; ja, オホーツク海, Ohōtsuku-kai) is a marginal sea of the western Pacific Ocean. It is located between Russia's Kamchatka Peninsula on the east, the Kuril Islands ...

, and the describer

Madoka Sasaki was a Japanese zoologist, who is known for his work on the cephalopods of Japan, as well as other groups such as salamanders. Sasaki was Professor of Zoology in the Fishery Department of the College of Agriculture at Tohoku Imperial University, Sap ...

named it ''Octopus salebrosus'' in 1920. When

Guy Coburn Robson Guy Coburn Robson (1888–1945) was a British zoologist, specializing in Mollusca, who first named and described '' Mesonychoteuthis hamiltoni'', the colossal squid. Robson studied at the marine biological station in Naples, and joined the staff o ...

revised the

Octopodidae The Octopodidae comprise the family containing the majority of known octopus species. Genera The World Register of Marine Species lists these genera: *'' Abdopus'' Norman & Finn, 2001 *'' Ameloctopus'' Norman, 1992 *'' Amphioctopus'' P. Fischer, ...

, he tentatively reassigned ''O. salebrosus'' to ''Bathypolypus'' based on its rough skin, deep web, and short arms. The only specimens available to Robson were females, so the

ligula In the brain, the taenia of the fourth ventricle (lingula, tenia of fourth ventricle) are two narrow bands of white matter, one on either side, which complete the lower part of the roof of the fourth ventricle. Each consists of a vertical and a ...

could not be examined, the ligulae of ''Bathypolypus'' are distinctively large and are laminated. Subsequent workers raised doubts about where this species should be placed until surveys of demersal fish in the eastern

Bering Sea The Bering Sea (, ; rus, Бе́рингово мо́ре, r=Béringovo móre) is a marginal sea of the Northern Pacific Ocean. It forms, along with the Bering Strait, the divide between the two largest landmasses on Earth: Eurasia and The Ameri ...

gave workers the opportunity to study many specimens of ''B. salebrosus''. The result was that it was placed in the new genus ''Sasakiopus''. ''Sasakiopus salebrosus'' is a

benthic The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning "t ...

octopus with two rows of suckers on each arm, with the arms being roughly two times the length of the mantle in adults. They do not show arm autotomy and no enlarged suckers are seen. The integument has a sculpture of extensive papillae which are flat-topped, closely set, and irregular. No white spots occur on the dorsum and no oceallae or enlarged or supraocular papillae are present. The third right arm is hectocotylised in the males, and these have a large ligula which is not laminated. In life,

Needham's sac Needham's sac (also called a spermatophore sac) is the part of the reproductive tract of cephalopods in which spermatophores are stored. Spermatophores are complex structures consisting of ropes of sperm and in some species include an ejaculatory a ...

extends into the dextral side of the mantle.

References

{{Taxonbar, from=Q14313223 Cephalopod genera Molluscs described in 1920 Enteroctopodidae