Taningia danae explained

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 1.7m (05.6feet)^[1] and total length of 2.3m (07.5feet). The largest known specimen, a mature female, weighed 161.4kg (355.8lb).^[2]

Taningia danae is named after Danish fisheries biologist Åge Vedel Tåning (1890–1958), who often traveled on the research vessel Dana.^[3]

Ecology

Taningia danae possesses bioluminescence, like other octopoteuthids. Its photophores are some of the largest such organs known to science, the organs being compared in size to fists or lemons. They possess a black membrane over the photophore that may conceal the organs, allowing the squid to blink its lights; this membrane has been compared to eyelids as a result.^[4]

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 disorient potential prey, as well as to illuminate the prey to make for easier capture in a dark environment. These flashes may also serve a role in courtship and territorial display.^[5]

As well as a predatorial characteristic, T. danae 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 disorient and startle the threat with a mock attack.^[6]

In 2012, T. danae was filmed twice more during a search for the giant squid for the Discovery Channel Special, Monster Squid: The Giant Is Real.^[7]

Remains of T. danae 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 farther along the shore.^[8] In early 2013, a 54kg (119lb) specimen with a length (excluding arms) of 103cm (41inches) was trawled at a depth of 240m (790feet) off the coast of Estaca de Bares, Galicia, Spain. It was loaned to the Spanish Institute of Oceanography.^[9] A largely intact 140kg (310lb) specimen was found floating around 100km off the South Australian coast and sent to Flinders University in Adelaide where it was dissected in July 2024. ^[10]

¹⁵N ratios showed that this squid is a top predator.^[11] In turn, they are eaten by the sperm whale.^{[12] [13] [14]}

Notes

a.This is the weight of a specimen from the North Atlantic measuring 1.6m (05.2feet) in mantle length. The previously reported maximum weight of 61.4kg (135.4lb) for T. danae (based on this same specimen) stems from a typographical error in the original paper^[15] of Roper & Vecchione (1993).

Further reading

• González, Á.F., Á. Guerra & F. Rocha 2003. New data on the life history and ecology of the deep-sea hooked squid Taningia danae. Sarsia 88(4): 297–301.
• Quetglas, A., K. Fliti, E. Massutí, W. Refes, B. Guijarro & S. Zaghdoudi 2006. First record of Taningia danae (Cephalopoda: Octopoteuthidae) in the Mediterranean Sea . 2006 . 10.3989/scimar.2006.70n1153 . Quetglas . Antoni . Fliti . Khaled . Massutí . Enric . Refes . Wahid . Guijarro . Beatríz . Zaghdoudi . Said . Scientia Marina . 70 . 153–155 . free . 10508/7451 . free . . Scientia Marina 70(1): 153–155.
• Santos, M.B., G.J. Pierce, Á.F. González, F. Santos, M.A. Vázquez, M.A. Santos & M.A. Collins 2001. First records of Taningia danae (Cephalopoda: Octopoteuthidae) in Galician waters (north-west Spain) and in Scottish waters (UK). Journal of the Marine Biological Association of the UK 81(2): 355–356.
• Zeidler, W. 1981. A giant deep-sea squid, Taningia sp., from South Australian waters. Transactions of the Royal Society of South Australia 105(4): 218.

External links

• Tree of Life web project: Taningia danae
• National Geographic: Monster Glowing Squid Caught on Camera
• BBC: Large squid lights up for attack

See also

• Giant squid
• Giant squid in popular culture

Notes and 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. [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. 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.
3. Web site: Taningia danae, a deep-sea bioluminescent squid . 10 March 2018 . Dr. James B. Wood . The Cephalopod Page.
4. Web site: Captain Cook's Calamari . seahistory.org . National Maritime Historical Society . 12 December 2022.
5. Kubodera, T., Y. Koyama & K. Mori 2006. Web site: Observations of wild hunting behaviour and bioluminescence of a large deep-sea, eight-armed squid, Taningia danae. .   Proceedings of the Royal Society B: Biological Sciences 274(1613): 1029–1034.
6. Young, R.E. & M. Vecchione 1999. Taningia danae Joubin, 1931. Version 1 January 1999. Tree of Life web project.
7. Monster Squid: The Giant Is Real. Discovery Channel.
8. Dale, A. 2008. "Monster from the Deep". Bermuda Royal Gazette, 8 July 2008.
9. http://www.europapress.es/galicia/noticia-aparece-galicia-calamar-gigante-54-kilos-mas-metro-largo-20130211114018.html Aparece en Galicia un calamar gigante de 54 kilos y más de un metro de largo
10. Web site: Rare octopus squid found dead in Southern Ocean dissected by researchers at SA university. abc.net.au. 18 July 2024.
11. Guerreiro, Miguel & Phillips, Richard A & Cherel, Yves & Ceia, Filipe R & Alvito, Pedro & Rosa, Rui & Xavier, José C. 2015. Habitat and trophic ecology of Southern Ocean cephalopods from stable isotope analyses. Marine Ecology Progress Series, published online on 18 June 2015.
12. Chua . Marcus A.H. . Lane . David J.W. . Ooi . Seng Keat . Tay . Serene H.X. . Kubodera . Tsunemi . Diet and mitochondrial DNA haplotype of a sperm whale (Physeter macrocephalus) found dead off Jurong Island, Singapore . PeerJ . 5 April 2019 . 7 . e6705 . 10.7717/peerj.6705. 30984481 . 6452849 . free .
13. Harvey . James T. . Friend . Theresa . McHuron . Elizabeth A. . Cephalopod remains from stomachs of sperm whales (Physeter macrocephalus) that mass-stranded along the Oregon coast . Marine Mammal Science . April 2014 . 30 . 2 . 609–625 . 10.1111/mms.12063.
14. EVANS . K . HINDELL . M . The diet of sperm whales (Physeter macrocephalus) in southern Australian waters . ICES Journal of Marine Science . December 2004 . 61 . 8 . 1313–1329 . 10.1016/j.icesjms.2004.07.026. 2004ICJMS..61.1313E . free .
15. Roper, C.F.E. & M. Vecchione 1993. Web site: A geographic and taxonomic review of Taningia danae Joubin, 1931 (Cephalopoda: Octopoteuthidae), with new records and observations on bioluminescence. . In: T. Okutani, R.K. O'Dor & T. Kubodera (eds.) Recent Advances in Cephalopod Fisheries Biology. Tokai University Press, Tokyo. pp. 441–456.