Dana Octopus Squid
Encyclopedia
The Dana Octopus Squid (Taningia danae) is a species of squid
in the family Octopoteuthidae
. It is one of the largest known squid
species, reaching a mantle
length of 1.7 m (5.6 ft) and total length of 2.3 m (7.5 ft). The largest known specimen, a mature female, weighed 61.4 kilograms (135.4 lb).
Taningia danae is named after Danish fisheries
biologist Aage Vedel Taaning (1890–1958), who often traveled on the research vessel Dana.
ese research team headed by Tsunemi Kubodera
managed to film T. danae in its natural habitat for the first time. The video footage, shot in deep water off Chichi-jima
in the northern Pacific Ocean
, shows T. danae emitting blinding flashes
of light from photophore
s on its arm
s as it attacks its prey. It is believed that this highly maneuverable squid uses the bright flashes to disorientate potential prey. These flashes may also serve to illuminate the prey to make for easier capture as well as a courtship and territorial display.
As well as a predatorial characteristic, Dana bioluminescence has also been inferred as a defense mechanism. Juveniles of this species have been observed moving rapidly in the direction of potential predators, as if hunting, to disorientate and startle the threat with a mock attack.
Remains of Dana Octopus Squid have, on occasion, been found washed ashore on beaches. In 2008, a mantle of T. danae was discovered by students in Bermuda
's Grape Bay, while tentacle
remnants were found further along the shore.
Squid
Squid are cephalopods of the order Teuthida, which comprises around 300 species. Like all other cephalopods, squid have a distinct head, bilateral symmetry, a mantle, and arms. Squid, like cuttlefish, have eight arms arranged in pairs and two, usually longer, tentacles...
in the family Octopoteuthidae
Octopoteuthidae
Octopoteuthidae is a family of squid comprising two genera. The family is characterised by tentacles which cease to grow after the paralarval stage; and the use of a penis, instead of a hectocotylus.-Species:*Genus Octopoteuthis**Octopoteuthis danae...
. It is one of the largest known squid
Cephalopod size
Size 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...
species, reaching a mantle
Mantle (mollusc)
The mantle is a significant part of the anatomy of molluscs: it is the dorsal body wall which covers the visceral mass and usually protrudes in the form of flaps well beyond the visceral mass itself.In many, but by no means all, species of molluscs, the epidermis of the mantle secretes...
length of 1.7 m (5.6 ft) and total length of 2.3 m (7.5 ft). The largest known specimen, a mature female, weighed 61.4 kilograms (135.4 lb).
Taningia danae is named after Danish fisheries
Fishery
Generally, a fishery is an entity engaged in raising or harvesting fish which is determined by some authority to be a fishery. According to the FAO, a fishery is typically defined in terms of the "people involved, species or type of fish, area of water or seabed, method of fishing, class of boats,...
biologist Aage Vedel Taaning (1890–1958), who often traveled on the research vessel Dana.
Hunting behaviour and bioluminescence
In 2005, a JapanJapan
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...
ese research team headed by Tsunemi Kubodera
Tsunemi Kubodera
is a Japanese zoologist with the National Science Museum of Japan. On September 30, 2004, Kubodera and his team became the first people to photograph a live giant squid in its natural habitat...
managed to film T. danae in its natural habitat for the first time. The video footage, shot in deep water off Chichi-jima
Chichi-jima
, formerly known as Peel Island and in the 19th century known to the English as part of the Bonin Islands, is the largest island in the Ogasawara archipelago. Chichi-jima is approximately 150 miles north of Iwo Jima. The island is within the political boundaries of Ogasawara Town, Ogasawara...
in the northern Pacific Ocean
Pacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
, shows T. danae emitting blinding flashes
Bioluminescence
Bioluminescence is the production and emission of light by a living organism. Its name is a hybrid word, originating from the Greek bios for "living" and the Latin lumen "light". Bioluminescence is a naturally occurring form of chemiluminescence where energy is released by a chemical reaction in...
of light from photophore
Photophore
A photophore is a light-emitting organ which appears as luminous spots on various marine animals, including fish and cephalopods. The organ can be simple, or as complex as the human eye; equipped with lenses, shutters, color filters and reflectors...
s on its arm
Cephalopod arm
A cephalopod arm is distinct from a tentacle, though the terms are often used interchangeably.Generally, cephalopod arms have suckers along most of their length, as opposed to tentacles, which have suckers only near their ends. Octopuses have eight arms and no tentacles, while squid and cuttlefish...
s as it attacks its prey. It is believed that this highly maneuverable squid uses the bright flashes to disorientate potential prey. These flashes may also serve to illuminate the prey to make for easier capture as well as a courtship and territorial display.
As well as a predatorial characteristic, Dana bioluminescence has also been inferred as a defense mechanism. Juveniles of this species have been observed moving rapidly in the direction of potential predators, as if hunting, to disorientate and startle the threat with a mock attack.
Bermuda
Bermuda is a British overseas territory in the North Atlantic Ocean. Located off the east coast of the United States, its nearest landmass is Cape Hatteras, North Carolina, about to the west-northwest. It is about south of Halifax, Nova Scotia, Canada, and northeast of Miami, Florida...
's Grape Bay, while tentacle
Tentacle
A tentacle or bothrium is one of usually two or more elongated flexible organs present in animals, especially invertebrates. The term may also refer to the hairs of the leaves of some insectivorous plants. Usually, tentacles are used for feeding, feeling and grasping. Anatomically, they work like...
remnants were found further along the shore.