Taningia danae

Dana octopus squid
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Order: Teuthida
Family: Octopoteuthidae
Genus: Taningia
Species: T. danae
Binomial name
Taningia danae
Joubin, 1931
Synonyms
  • Cucioteuthis unguiculatus
    Joubin, 1898
  • Cucioteuthis unguiculatus
    Clarke, 1956
  • Cucioteuthis unguiculata
    Rees & Maul, 1956
  • Cucioteuthis unguiculata
    Clarke, 1962
  • Enoploteuthis cookii
    Owen, 1881

Taningia danae, the Dana octopus squid, 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)[1] and total length of 2.3 m (7.5 ft).[2] The largest known specimen, a mature female, weighed 161.4 kilograms (356 lb).[3][nb a]

Taningia danae is named after Danish fisheries biologist Åge Vedel Tåning (1890–1958), who often traveled on the research vessel Dana.

Hunting behaviour and bioluminescence

In 2005, a Japanese 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 photophores on its arms 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.[2]

As well as a predatorial characteristic, Dana bioluminescence has also been suggested to be 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.[4]

In 2012, Taningia danae was filmed twice more during a search for the giant squid for the Discovery Channel Special, Monster Squid: The Giant Is Real.[5]

Still image from the first video footage of a live Taningia danae in its natural habitat.
Arms and buccal mass of T. danae

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.[6] In early 2013, a 54 kg (119 lb) specimen with a length (excluding arms) of 103 cm (3.38 ft) was trawled at a depth of 240 m (790 ft) off the coast of Estaca de Bares, Galicia, Spain. It was loaned to the Spanish Institute of Oceanography.[7]

In popular culture

James Rollins' SIGMA Force Book 4: The Judas Strain (2007) provides detailed descriptions of sightings of schools of giant predatory squid in the waters off the island of Pusat[8] and graphic descriptions of collaboratortive squid attacks of several characters.[8][9] In the book's "Author's Note: Truth or Fiction: Fauna", Rollins shares: "As to our predatory squids, I based them on the species Taningia danae, which grow to six feet in length, hunt in packs, have brilliant light displays, and bear claws on their suckers. Definitely tough calamari."[10]

Notes

a.^ This is the weight of a specimen from the North Atlantic measuring 1.6 m (5.2 ft) in mantle length.[3] The previously reported maximum weight of 61.4 kg (135 lb) for T. danae (based on this same specimen) stems from a typographical error in the original paper[11] of Roper & Vecchione (1993).[3]

References

  1. ↑ Nesis, K.N. 1982. Abridged key to the cephalopod mollusks of the world's ocean. Light and Food Industry Publishing House, Moscow. 385+ii pp. (Russian) [Translated into English by B. S. Levitov, ed. by L. A. Burgess 1987. Cephalopods of the world. T.F.H. Publications, Neptune City, NJ. 351pp.]
  2. ↑ 2.0 2.1 Kubodera, T., Y. Koyama & K. Mori 2006. Observations of wild hunting behaviour and bioluminescence of a large deep-sea, eight-armed squid, Taningia danae. PDF (295 KB) Proceedings of the Royal Society B: Biological Sciences 274(1613): 1029–1034. doi:10.1098/rspb.2006.0236
  3. ↑ 3.0 3.1 3.2 Roper, C.F.E. & P. Jereb 2010. Family Octopoteuthidae. In: P. Jereb & C.F.E. Roper (eds.) Cephalopods of the world. An annotated and illustrated catalogue of species known to date. Volume 2. Myopsid and Oegopsid Squids. FAO Species Catalogue for Fishery Purposes No. 4, Vol. 2. FAO, Rome. pp. 262–268.
  4. ↑ Young, R.E. & M. Vecchione 1999. Taningia danae Joubin, 1931. Version 1 January 1999. Tree of Life web project.
  5. ↑ Monster Squid: The Giant Is Real. Discovery Channel.
  6. ↑ Dale, A. 2008. "Monster from the Deep". Bermuda Royal Gazette, July 8, 2008.
  7. ↑ Aparece en Galicia un calamar gigante de 54 kilos y más de un metro de largo. Europa Press, 11 February 2013. (Spanish)
  8. ↑ 8.0 8.1 Rollins, James (2007). SIGMA Force Book 4: The Judas Strain. p. 66.
  9. ↑ Rollins, James (2007). SIGMA Force Book 4: The Judas Strain. p. 46.
  10. ↑ Rollins, James (2007). The Judas Strain. p. Author's Note, p. 2.
  11. ↑ Roper, C.F.E. & M. Vecchione 1993. A geographic and taxonomic review of Taningia danae Joubin, 1931 (Cephalopoda: Octopoteuthidae), with new records and observations on bioluminescence. PDF In: T. Okutani, R.K. O'Dor & T. Kubodera (eds.) Recent Advances in Cephalopod Fisheries Biology. Tokai University Press, Tokyo. pp. 441–456.

External links

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See also