Greater Hooked Squid

Greater Hooked Squid
Onykia ingens (~400 mm ML)
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Cephalopoda
Subclass:	Coleoidea
Order:	Teuthida
Suborder:	Oegopsina
Family:	Onychoteuthidae
Genus:	Onykia
Subgenus:	Moroteuthopsis
Species:	O. ingens
Binomial name
Onykia ingens (Smith, 1881)
Synonyms
Onychoteuthis ingens Smith, 1881 Moroteuthis ingens (Smith, 1881)

The Greater Hooked Squid (Onykia ingens) is a species of squid in the family Onychoteuthidae. It occurs worldwide in subantartic oceans.

Although O. ingens was long attributed to the genus Moroteuthis, several authors have recently agreed that Moroteuthis is a junior synonym of Onykia.^[1]

Size and growth

The size of a fully grown Greater Hooked Squid, inclusive of tentacles, is currently unknown. Many estimates, however, predict that the mantle may reach lengths of up to 94 cm (37 in). Research has found that egg sizes of the squid average 2.1 mm inside mature females, while juveniles average 4.6 mm or larger. Juveniles are presumed to live near the surface, until they reach a mantle length of approximately 200 mm, at which time they relocate to deeper water, and larger prey. Greater Hooked Squid exhibit sexual dimorphism, with females growing linearly twice as fast as males, and reaching a fully mature size of more than five times that of male counterparts.^[2]

Penis elongation has been observed in this species; when erect, the penis may be as long as the mantle, head and arms combined.^[3][4] As such, deep water squid like M. ingens have the greatest known penis length relative to body size of all mobile animals, second in the entire animal kingdom only to certain sessile barnacles.^[3]

Left: A dissected male specimen of Onykia ingens, showing a non-erect penis (the white tubular structure located below most of the other organs)

Right: A specimen of the same species exhibiting elongation of the penis to 67 cm in length

Ecology

It is generally accepted that there are large dietary variations between large and small Greater Hooked Squid. One of the most common findings is that juvenile squid (>200 mm ML) consume a greater percentage of crustaceans and cephalopods compared to their size than mature squid, which consume a large percentage of fish and virtually no crustaceans.^[5] Globally, however, myctophid fish (lantern fish) are seen as common prey.^[6] Larger squid are known to practice cannibalism (accounting for up to 6% of diet).^[7] The Greater Hooked Squid, as with many (if not all) large squid, has a number of predators. These include the patagonian toothfish, king penguin, wandering albatross, pilot whale, bottlenose whale, dwarf sperm whale, sperm whale, and other types of squid.^[8]

• 

  Tentacular club of Moroteuthis ingens

• 

  Piece of ventral mantle skin

• 

  Gladius with cross-sections

References

1. ^ Bolstad, K.S.R. 2010. Systematics of the Onychoteuthidae Gray, 1847 (Cephalopoda: Oegopsida). Zootaxa 2696: 1–186. Preview
2. ^ Bolstad, K. 2003. Spotlight on: Moroteuthis ingens. The Octopus News Magazine Online.
3. ^ ^{a b} Arkhipkin, A.I. & V.V. Laptikhovsky 2010. Observation of penis elongation in Onykia ingens: implications for spermatophore transfer in deep-water squid. Journal Molluscan Studies, published online on June 30, 2010. doi:10.1093/mollus/eyq019
4. ^ Walker, M. 2010. Super squid sex organ discovered. BBC Earth News, July 7, 2010.
5. ^ Phillips, K., P. Nichols & G. Jackson 2003. Size-related dietary changes observed in the squid Moroteuthis ingens at the Falkland Islands: stomach contents and fatty-acid analyses. Polar Biology 26(7): 474-485.
6. ^ Phillips, K., P. Nichols & G. Jackson 2003. Dietary variation of the squid Moroteuthis ingens at four sites in the Southern Ocean: stomach contents, lipid and fatty acid profiles. Journal of the Marine Biological Association of the UK 83: 523-534.
7. ^ Cherel, Y. & G. Duhamel 2003. Diet of the squid Moroteuthis ingens (Teuthoidea: Onychoteuthidae) in the upper slope waters of the Kerguelen Islands. Marine Ecology Progress Series 250: 197–203.
8. ^ CephBase: Predators of Moroteuthis ingens.

External links

• CephBase: Greater Hooked Squid
• Tree of Life web project: Onykia ingens
• First observation of a double tentacle bifurcation in cephalopods

This squid-related article is a stub. You can help Wikipedia by expanding it.v · Categories: Squid stubs Squid Animals described in 1881 Wikimedia Foundation. 2010. Игры ⚽ Поможем написать реферат CAUCE Academy for Technology and Academics Look at other dictionaries: Hooked squid — Onychoteuthis banksii Scientific classification Kingdom: Animalia …   Wikipedia Spawn (biology) — The spawn (eggs) of a clownfish. The black spots are the eyes developing. Spawn refers to the eggs and sperm released or deposited, usually into water, by aquatic animals. As a verb, spawn refers to the process of releasing the eggs and sperm,… …   Wikipedia commercial fishing — Introduction  the taking of fish and other seafood and resources from oceans, rivers, and lakes for the purpose of marketing them.       Fishing is one of the oldest employments of humankind. Ancient heaps of discarded mollusk shells (shell… …   Universalium Seabird — This article is about the animal. For the alternative rock band of the same name, see Seabird (band). The Sooty Tern is highly aerial and marine and will spend months flying at sea, returning to land only for breeding.[1] Seabirds (also known as… …   Wikipedia List of birds of Argentina — This is a list of the bird species recorded in Argentina. The avifauna of Argentina includes a total of 1026 species, of which 20 are endemic, 7 have been introduced by humans, and 70 are rare or accidental. 45 species are globally… …   Wikipedia List of birds of Peru — This is a list of the bird species recorded in Peru. The avifauna of Peru includes a total of 1879 species, of which 139 are endemic, 3 have been introduced by humans, and 72 are rare or accidental. 91 species are globally threatened.This list s… …   Wikipedia Giant trevally — Scientific classification Kingdom: Animalia Phylum …   Wikipedia List of birds of Wales — This list of birds of Wales includes every species of bird that has been recorded in a wild state in Wales. Compared to the avifauna of Britain as a whole, Wales has fewer breeding species but these include a number of moorland species such as… …   Wikipedia List of birds of Uruguay — This is a list of the bird species recorded in Uruguay. The avifauna of Uruguay includes a total of 477 species, of which 5 have been introduced by humans, and 46 are rare or accidental. 18 species are globally threatened.This list s taxonomic… …   Wikipedia Procellariiformes — Taxobox name = Procellariiformes fossil range = Middle Eocene – Recent image width = 250px image caption = Cape Petrel Daption capense regnum = Animalia phylum = Chordata classis = Aves infraclassis = Neognathae ordo = Procellariiformes ordo… …   Wikipedia 18+ © Academic, 2000-2024 Contact us: Technical Support, Advertising Dictionaries export, created on PHP, Joomla, Drupal, WordPress, MODx. Mark and share Search through all dictionaries Translate… Search Internet Share the article and excerpts Direct link … Do a right-click on the link above and select “Copy Link”