Enteroctopus

''Enteroctopus'' is an octopus genus 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 '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 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, often comprising one-fifth the length of the arm. Octopuses in this genus have large, paddle-like papillae 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 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 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, along the North Pacific Rim to Japan, including the Okhotsk and Bering Seas. The other three species are found in the Southern Hemisphere; ''E. megalocyathus'' occurs on the southeastern coast of South America, ''E. magnificus'' on the southwestern coast of Africa from Namibia to Port Elizabeth, South Africa, and ''E. zealandicus'' in temperate New Zealand.

Size

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

See also

* Gigantic octopus
* Giant squid
* Colossal squid
* Cephalopod size
*Kraken
* Lusca

Footnotes

References

{{Authority control

Enteroctopodidae
Taxa named by Jules François Mabille