''Enteroctopus'' is an octopus

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

whose members are sometimes known as giant octopus.

Etymology

The generic name ''Enteroctopus'' was created by Alphonse Tremeau de Rochebrune and Jules François Mabille in 1887 and published in 1889, joining

Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic p ...

'gut' and , thus 'octopus ith arms similar toguts.'

Description

''Enteroctopus'' is a genus of generally temperate octopuses. Members of this genus are characterized by their large size and are often known as giant octopuses. ''Enteroctopus'' species have distinct longitudinal wrinkles or folds dorsally and laterally on their bodies. Their heads are distinctly narrower than the mantle width. The

hectocotylus A hectocotylus (plural: ''hectocotyli'') is one of the arms of male cephalopods that is specialized to store and transfer spermatophores to the female. Structurally, hectocotyli are muscular hydrostats. Depending on the species, the male may use i ...

of the males in this genus, found on the third right arm, is long and narrow in comparison with other genera in the family

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, 1 ...

, often comprising one-fifth the length of the arm. Octopuses in this genus have large, paddle-like

papilla Papilla (Latin, 'nipple') or papillae may refer to: In animals * Papilla (fish anatomy), in the mouth of fish * Basilar papilla, a sensory organ of lizards, amphibians and fish * Dental papilla, in a developing tooth * Dermal papillae, part of ...

e instead of the more conical papillae in other octopus genera.

Species

Genus ''Enteroctopus'' at present consists of four species, tabulated below:

Type species

''E. membranaceus'' has often been regarded as

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specime ...

of the genus, not because it was designated as such by Rochebrune and Mabille when they erected the genus, but because it was the first named species in the genus. Robson in his 1929 monograph of octopods regarded ''E. membranaceus'' as a '' species dubium'' because the original description was insufficient to identify an individual species, the

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of sever ...

was an immature specimen, and the type specimen no longer existed. As such, the genus was considered invalid until Hochberg resurrected it in 1998. Hochberg noted that Robson had considered ''E. membranaceus'' a junior synonym of '' E. megalocyathus'', the second species assigned to the genus by Rochebrune and Mabille in their 1889 description. Additionally, since Rochebrune and Mabille did not actually assign type status to ''E. membranaceus'', Hochberg concluded that ''Enteroctopus'' was indeed a valid genus and transferred type-species status to ''E. megalocyathus'' based on his conclusion that ''E. megalocyathus'' and ''E. membranaceus'' are the same species.

Distribution

Species in the genus ''Enteroctopus'' are restricted to the temperate areas of the Northern and Southern Hemispheres. ''E. dofleini'' is the only member of the genus found in the Northern Hemisphere, and also the most widely distributed: It is found from

Southern California Southern California (commonly shortened to SoCal) is a geographic and cultural region that generally comprises the southern portion of the U.S. state of California. It includes the Los Angeles metropolitan area, the second most populous urban a ...

, along the North Pacific Rim to Japan, including the

Okhotsk Okhotsk ( rus, Охотск, p=ɐˈxotsk) is an urban locality (a work settlement) and the administrative center of Okhotsky District of Khabarovsk Krai, Russia, located at the mouth of the Okhota River on the Sea of Okhotsk. Population: ...

and Bering Seas. The other three species are found in the Southern Hemisphere; ''E. megalocyathus'' occurs on the southeastern coast of

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sout ...

, ''E. magnificus'' on the southwestern coast of

Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...

from

Namibia Namibia (, ), officially the Republic of Namibia, is a country in Southern Africa. Its western border is the Atlantic Ocean. It shares land borders with Zambia and Angola to the north, Botswana to the east and South Africa to the south and ea ...

to Port Elizabeth,

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. It is bounded to the south by of coastline that stretch along the Atlantic Ocean, South Atlantic and Indian Oceans; to the ...

, and ''E. zealandicus'' in temperate

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

Size

The member of this genus that best embodies the common name "giant octopus" is ''

Enteroctopus dofleini The giant Pacific octopus (''Enteroctopus dofleini''), also known as the North Pacific giant octopus, is a large marine cephalopod belonging to the genus ''Enteroctopus''. Its spatial distribution includes the coastal North Pacific, along Mexico ...

'', which holds the record of being the world's largest octopus based on direct measurements of a individual, weighed live. This octopus had a total length near to . The remaining members of the genus are substantially smaller, with ''E. megalocyathus'' having an average mass of and reaching a total length of . ''E. magnificus'' reaches a total length of around .

Footnotes

References

{{Authority control Enteroctopodidae Taxa named by Jules François Mabille