Giant octopus
Encyclopedia
Enteroctopus is an octopus
genus
, many of whose members are sometimes known as giant octopuses.
es. Members of the genus Enteroctopus are characterized by their large size and are often known as the giant octopuses. Enteroctopus species have distinct longitudinal wrinkles or folds dorsally and laterally on the body. The head is 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.
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 was no longer extant. 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 by virtual monotypy.
Species in the genus Enteroctopus are restricted to the temperate areas of the Northern
and Southern Hemisphere
s. E. dofleini is the only member of the genus found in the Northern Hemisphere and also the most widely distributed, occurring from San Diego
, California
along the North Pacific Rim to Japan
, including the Okhotsk
and Bering Sea
s. 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
.
Octopus
The octopus is a cephalopod mollusc of the order Octopoda. Octopuses have two eyes and four pairs of arms, and like other cephalopods they are bilaterally symmetric. An octopus has a hard beak, with its mouth at the center point of the arms...
genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
, many of whose members are sometimes known as giant octopuses.
Description
Enteroctopus is a genus of generally temperate octopusOctopus
The octopus is a cephalopod mollusc of the order Octopoda. Octopuses have two eyes and four pairs of arms, and like other cephalopods they are bilaterally symmetric. An octopus has a hard beak, with its mouth at the center point of the arms...
es. Members of the genus Enteroctopus are characterized by their large size and are often known as the giant octopuses. Enteroctopus species have distinct longitudinal wrinkles or folds dorsally and laterally on the body. The head is distinctly narrower than the mantle width. The hectocotylus
Hectocotylus
A hectocotylus is one of the arms of the male of most kinds of cephalopods that is modified in various ways to effect the fertilization of the female's eggs. It is a specialized, extended muscular hydrostat used to store spermatophores, the male gametophore...
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
Octopodidae
Octopodidae is the family containing the majority of known octopus species.-Subfamilies and species:*Basal genus Vulcanoctopus*Genus incertae sedis Histoctopus*Subfamily Bathypolypodinae**Genus Bathypolypus**Genus Benthoctopus...
, 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.
Type species
Enteroctopus membranaceus has often been regarded as type speciesType species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
of the genus, not because it was designated as such by Rochebrune and Mabille
Jules François Mabille
Jules François Mabille was a French malacologist who discovered several species of molluscs....
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
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
was an immature specimen, and the type specimen was no longer extant. 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
Enteroctopus megalocyathus
Enteroctopus megalocyathus, also known as the Southern Red Octopus, is a medium-sized octopus, and the type species for the genus Enteroctopus.-Size and description:E...
, 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 by virtual monotypy.
Distribution
Northern Hemisphere
The Northern Hemisphere is the half of a planet that is north of its equator—the word hemisphere literally means “half sphere”. It is also that half of the celestial sphere north of the celestial equator...
and Southern Hemisphere
Southern Hemisphere
The Southern Hemisphere is the part of Earth that lies south of the equator. The word hemisphere literally means 'half ball' or "half sphere"...
s. E. dofleini is the only member of the genus found in the Northern Hemisphere and also the most widely distributed, occurring from San Diego
San Diego, California
San Diego is the eighth-largest city in the United States and second-largest city in California. The city is located on the coast of the Pacific Ocean in Southern California, immediately adjacent to the Mexican border. The birthplace of California, San Diego is known for its mild year-round...
, California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
along the North Pacific Rim to Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
, including the Okhotsk
Sea of Okhotsk
The Sea of Okhotsk is a marginal sea of the western Pacific Ocean, lying between the Kamchatka Peninsula on the east, the Kuril Islands on the southeast, the island of Hokkaidō to the far south, the island of Sakhalin along the west, and a long stretch of eastern Siberian coast along the west and...
and Bering Sea
Bering Sea
The Bering Sea is a marginal sea of the Pacific Ocean. It comprises a deep water basin, which then rises through a narrow slope into the shallower water above the continental shelves....
s. The other three species are found in the Southern Hemisphere; E. megalocyathus occurs on the southeastern coast of South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
, E. magnificus on the southwestern coast of Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
from Namibia
Namibia
Namibia, officially the Republic of Namibia , is a country in southern Africa whose western border is the Atlantic Ocean. It shares land borders with Angola and Zambia to the north, Botswana to the east and South Africa to the south and east. It gained independence from South Africa on 21 March...
to Port Elizabeth
Port Elizabeth, Eastern Cape
Port Elizabeth is one of the largest cities in South Africa, situated in the Eastern Cape Province, east of Cape Town. The city, often shortened to PE and nicknamed "The Friendly City" or "The Windy City", stretches for 16 km along Algoa Bay, and is one of the major seaports in South Africa...
, South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
, and E. zealandicus in temperate New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
.
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 71 kg (156.5 lb) individual weighed live. This octopus had a total length of 7 m (23 ft). The remaining members of the genus are substantially smaller, with E. megalocyathus having an average mass of 4 kg and reaching a total length of 1 m. E. magnificus reaches a total length of around 1.5 m.Species
- Genus Enteroctopus
- Enteroctopus dofleini, Giant Pacific Octopus
- Enteroctopus magnificus, Southern Giant Octopus
- Enteroctopus megalocyathusEnteroctopus megalocyathusEnteroctopus megalocyathus, also known as the Southern Red Octopus, is a medium-sized octopus, and the type species for the genus Enteroctopus.-Size and description:E...
- Enteroctopus zealandicus
See also
- Gigantic octopusGigantic octopusAn unknown species of gigantic octopus has been hypothesised as a source of reports of sea monsters such as the lusca and the kraken as well as the source of some of the carcasses of unidentified origin known as globsters like the St. Augustine Monster. The species that the St...
- Giant squidGiant squidThe giant squid is a deep-ocean dwelling squid in the family Architeuthidae, represented by as many as eight species...
- Colossal SquidColossal SquidThe colossal squid , sometimes called the Antarctic or giant cranch squid, is believed to be the largest squid species in terms of mass. It is the only known member of the genus Mesonychoteuthis...
- Cephalopod sizeCephalopod sizeSize has been one of the most interesting aspects of cephalopod science to the general public. This article lists the largest cephalopods from various groups, sorted in order of mantle length, total length, weight, and shell diameter...
- KrakenKrakenKraken are legendary sea monsters of giant proportions said to have dwelt off the coasts of Norway and Iceland.In modern German, Krake means octopus but can also refer to the legendary Kraken...
- LuscaLuscaThe lusca is a name given to a sea monster reported from the Caribbean. It has been suggested by cryptozoologists that the lusca is a gigantic octopus, far larger than the known giant octopuses of the genus Enteroctopus.-Sightings:...