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Temporal range: (at least) Late Cretaceous–Recent[1]
Photo of squid with 8 short arms and two longer tentacles
European squid (Loligo vulgaris)
Scientific classification edit
Kingdom: Animalia
Phylum: Mollusca
Class: Cephalopoda
Superorder: Decapodiformes
Order: Teuthida
A. Naef, 1916

Plesioteuthididae (incertae sedis)

Squid are cephalopods in the order Teuthida with elongated bodies, large eyes, eight arms and two tentacles. Like all other cephalopods, squid have a distinct head, bilateral symmetry, and a mantle. They are mainly soft-bodied, like octopuses, but have a small internal skeleton in the form of a rod-like gladius or pen, made of chitin.

Squid can change colour for camouflage and signalling. Some species are bioluminescent, using their light for counter-illumination camouflage.

Taxonomy and phylogeny

Squid are members of the class Cephalopoda, subclass Coleoidea. The squid orders Myopsida and Oegopsida are in the superorder Decapodiformes (from the Greek for "ten-legged"). Two other orders of decapodiform cephalopods are also called squid, although they are taxonomically distinct from squids and differ recognizably in their gross anatomical features. They are the bobtail squid of order Sepiolida and the ram's horn squid of the monotypic order Spirulida. The vampire squid, however, is more closely related to the octopuses than to any squid.[2]

The cladogram, not fully resolved, is based on Sanchez et al, 2018. Their molecular phylogeny used mitochondrial and nuclear DNA marker sequences; they comment that a robust phylogeny "has proven very challenging to obtain". If it is accepted that Sepiidae cuttlefish are a kind of squid, then the squids, excluding the vampire squid, form a clade as illustrated.[2] Orders are shown in boldface; all the families not included in those orders are in the paraphyletic order "Oegopsida".


Nautilus Nautilus Palau.JPG

Octopuses and allies

Octopoda, Argonautoidea, and Cirrina Papierboot Argonauta 200705181139.jpg

Vampyroteuthidae (vampire squid) Vampire des abysses.jpg

Squid, cuttlefish

Cranchiinae (glass squid A) Cranchiidae sp (cropped).jpg


Psychroteuthidae (glacial squid) Psychroteuthis glacialis paralarva.jpg

Onychoteuthidae (hooked squid) Onychoteuthis banksii2.jpg

Taoniinae (glass squid B)

Architeuthidae (giant squid) Architeuthis princeps image modified.PNG

Lepidoteuthidae (Grimaldi scaled squid) Lepidoteuthis grimaldii 617 mm ML.jpg

Octopoteuthidae (octopus squid) Taningia danae.gif

Ancistrocheiridae (sharpear enope squid) Ancistrocheirus lesueurii.jpg

Lycoteuthidae (firefly squid) Lycoteuthis lorigera male.jpg

Pyroteuthidae (fire squid) Pyroteuthismargaritifera.jpg

Bathyteuthidae Bathyteuthisabyssicola (top).jpg

Ommastrephidae (flying squid) Lesser Flying Squid - Todaropsis eblanae.jpg

Pholidoteuthidae Pholidoteuthis massyae (cropped).jpg

Gonatidae (armhook squid) Berryteuthis magister.jpg

Chiroteuthidae (whip-lash squid[a]) Chiroteuthid.png

Sepiolida (bobtail squid) Austrorossia mastigophora (rotated).jpg

Sepiadariidae (pyjama and bottletail squid) Striped pyjama squid.jpg

Chtenopterygidae Chtenopteryx sicula 1 (rotated).jpg

Thysanoteuthidae Thysanoteuthis rhombus.jpg

Enoploteuthidae Mollusques méditeranéens (Abralia veranyi).jpg

Brachioteuthidae Brachioteuthis riisei1.jpg


Histioteuthidae (cock-eyed squid) Histioteuthidae - Histioteuthis bonnellii.JPG

Batoteuthidae (bush-club squid)

Mastigoteuthidae (whip-lash squid) Mastigoteuthis agassizii1.jpg

Joubiniteuthidae (Joubin's squid) Joubiniteuthis portieri.jpg

Magnapinnidae (bigfin squid) Magnapinna talismani.jpg

Spirulida (ram's horn squid) Spirula spirula illustration.jpg

Myopsida (neritic squid) Loliginidae Loligo vulgaris1.jpg

Sepiidae (cuttlefish) Sepia officinalis1.jpg

Idiosepiidae (pygmy squid)


Crown Coleoids (the ancestors of octopuses and squid) diverged at the end of the Paleozoic, in the Permian. Squid diverged during the Jurassic, but many squid families appeared in or after the Cretaceous.[3]

Squid have differentiated from their ancestral molluscs such that the body plan has been condensed antero-posteriorly and extended dorso-ventrally. What may have been the foot of the ancestor is modified into a complex set of tentacles and highly developed sense organs, including advanced eyes similar to those of vertebrates.[4]

The ancestral shell has been lost, with only an internal gladius, or pen, remaining. The pen, made of a chitin-like material,[4][5] is a feather-shaped internal structure that supports the squid's mantle and serves as a site for muscle attachment. The cuttlebone or sepion of the Sepiidae is calcareous and appears to have evolved afresh in the Tertiary.[6]


Composite diagram illustrating basic squid features (ventral aspect)

The head and foot of the squid are at one end of a long body, and this end is functionally anterior, leading the animal as it moves through the water. The foot has been transformed into a set of eight arms and two tentacles, which surround the mouth; each takes the form of a muscular hydrostat. These are flexible and prehensile, and usually bear disc-like suckers. In the mature male, the outer half of one of the left arms is hectocotylised – and ends in a copulatory pad rather than suckers. This is used for depositing a spermatophore inside the mantle cavity of a female. A ventral part of the foot has been converted into a funnel through which water exits the mantle cavity.[4]

The main body mass is enclosed in the mantle, which has a swimming fin along each side. These fins are not the main source of locomotion in most species. The mantle wall is heavily muscled and inside, the visceral mass, which is covered by a thin, membranous epidermis, forms a cone-shaped posterior region known as the "visceral hump". The mollusc shell is reduced to an internal, longitudinal chitinous "pen" in the functionally dorsal part of the animal; the pen acts to stiffen the squid and provides attachments for muscles.[4]

On the functionally ventral part of the body is an opening to the mantle cavity, which contains the gills (ctenidia) and openings from the excretory, digestive and reproductive systems. An inhalant siphon behind the funnel draws water into the mantel cavity via a valve. The squid uses the funnel for locomotion via precise jet propulsion.[7] In this form of locomotion, water is sucked into the mantle cavity and expelled out of the funnel in a fast, strong jet. The direction of travel is varied by the orientation of the funnel.[4] Squid are strong swimmers and certain species can "fly" for short distances out of the water.[8]


Controllable chromatophores of different colours in the skin of a squid allow it to change its coloration and patterns rapidly, whether for camouflage or signalling

Squid make use of different kinds of camouflage, namely active camouflage for background matching (in shallow water) and counter-illumination. This helps to protect them from their predators and allows them to approach their prey.[9][10]

The skin is covered in controllable chromatophores of different colours, enabling the squid to match its coloration to its surroundings.[9][11] The play of colours may also distract prey from the squid's approaching tentacles.[12] The skin also contains light reflectors called iridophores and leucophores which, when activated over milliseconds, create changeable skin patterns of polarized light.[13][14] Such skin camouflage may serve various functions, such as contrast enhancement and communication with nearby squid, prey detection, navigation, and orientation during hunting or seeking shelter.[13] Neural control of the iridophores enabling rapid changes in skin iridescence appears to be regulated by a cholinergic process affecting reflectin proteins.[14]

Principle of counter-illumination camouflage of the firefly squid, Watasenia scintillans. When seen from below by a predator, the animal's light helps to match its brightness and colour to the sea surface above

Some mesopelagic squid such as the firefly squid (Watasenia scintillans) and the midwater squid (Abralia veranyi) use counter-illumination camouflage, generating light to match the downwelling light from the ocean surface.[10][15][16] This creates the effect of countershading, making the underside lighter than the upperside.[10]


Fossil Loligosepia aalensis from the lower Jurassic; the ink sac is still full of black eumelanin pigment.

Squid distract attacking predators by ejecting a cloud of ink, giving themselves an opportunity to escape.[17][18] The ink gland and its associated ink sac empties into the rectum close to the anus, allowing the squid to rapidly discharge black ink into the mantle cavity and surrounding water. The ink is a suspension of melanin particles.[19]

Nervous system

Cephalopods have the most highly developed nervous systems among invertebrates. Squids have a complex brain in the form of a nerve ring encircling the oesophagus, enclosed in a cartilaginous cranium. Paired cerebral ganglia above the oesophagus receive sensory information from the eyes and statocysts, and further ganglia below control the muscles of the mouth, foot, mantle and viscera. Giant axons up to 1 mm in diameter convey messages with great rapidity to the circular muscles of the mantle wall allowing a synchronous, powerful contraction and maximum speed via the jet propulsion system.[4]

The paired eyes, on either side of the head, are housed in capsules fused to the cranium. Their structure is very similar to that of a fish eye, with a globular lens that has a depth of focus from 3 cm (1 in) to infinity. The image is focused by changing the position of the lens, as in a camera or telescope, rather than changing the shape of the lens, as in the human eye. Squid adjust to changes in light intensity by expanding and contracting the slit-shaped pupil.[4] Deep sea squids in the Histioteuthidae family have eyes of two different types and orientation. The large left eye is tubular in shape and looks upwards, presumably searching for the silhouettes of animals higher in the water column. The normally-shaped right eye points forwards and downwards to detect prey.[20]

The statocysts are involved in maintaining balance and are analogous to the inner ear of fish. They are housed in cartilaginous capsules on either side of the cranium. They provide the squid with information on its body position in relation to gravity, its orientation, acceleration and rotation, and are able to perceive incoming vibrations. Without the statocysts, the squid cannot maintain equilibrium.[4] Squid appear to have limited hearing.[21]

Squid are among the most intelligent invertebrates. For example, groups of Humboldt squid hunt cooperatively, using active communication.[22]

Reproductive system

Male Onykia ingens with penis erected to 67 cm (26 in)

The sexes are separate in squid, there being a single gonad in the posterior part of the body with fertilisation being external, and usually taking place in the mantle cavity of the female. The male has a testis from which sperm pass into a single gonoduct where they are rolled together into a long bundle, or spermatophore. The gonoduct is elongated into a "penis" which extends into the mantle cavity and through which spermatophores are ejected. In shallow water species, the penis is short, and the spermatophore is removed from the mantle cavity by a tentacle of the male, which is specially adapted for the purpose and known as a hectocotylus, and placed inside the mantle cavity of the female during mating.[4]

The female has a large translucent ovary, situated towards the posterior of the visceral mass. From here, eggs travel along the gonocoel, where there are a pair of white nidamental glands, which lie anterior to the gills. Also present are red-spotted accessory nidamental glands containing symbiotic bacteria; both organs are associated with nutrient manufacture and forming shells for the eggs. The gonocoel enters the mantle cavity at the gonopore, and in some species, receptacles for storing spermatophores are located nearby, in the mantle wall.[4]

In shallow-water species of the continental shelf and epipelagic or mesopelagic zones, it is frequently one or both of arm pair IV of males that are modified into hectocotyli.[23] However, most deep-sea squid lack hectocotyl arms and have longer penises; Ancistrocheiridae and Cranchiinae are exceptions.[24] Giant squid of the genus Architeuthis are unusual in that they possess both a large penis and modified arm tips, although whether the latter are used for spermatophore transfer is uncertain.[24] Penis elongation has been observed in the deep-water species Onykia ingens; when erect, the penis may be as long as the mantle, head, and arms combined.[24][25] As such, deep-water squid 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.[24]

Digestive system

Diagram labeling siphon, intestine, nidamental gland, accessory nidamental gland, renal pore, and branchial heart.
Ventral view of the viscera of a female Chtenopteryx sicula

Like all cephalopods, squids are predators and have complex digestive systems. The mouth is equipped with a sharp, horny beak mainly made of chitin[26] and cross-linked proteins, which is used to kill and tear prey into manageable pieces. The beak is very robust, but does not contain minerals, unlike the teeth and jaws of many other organisms, including marine species.[27] The stomachs of captured whales often have indigestible squid beaks inside. The mouth contains the radula, the rough tongue common to all molluscs except bivalvia, which is equipped with multiple rows of teeth.[4] In some species, toxic saliva helps to control large prey; when subdued, the food can be torn in pieces by the beak, moved to the oesophagus by the radula, and swallowed.[28]

The food bolus is moved along the gut by peristalsis. The long oesophagus leads to a muscular stomach which is found roughly in the middle of the visceral mass. The digestive gland, which is equivalent to a vertebrate liver, diverticulates here, as does the pancreas, and both of these empty into the caecum, a pouch-shaped sac where most of the absorption of nutrients takes place.[4] Indigestible food can be passed directly from the stomach to the rectum where it joins the flow from the caecum and is voided through the anus into the mantle cavity.[4] Cephalopods are short-lived, and in mature squid, priority is given to reproduction;[29] the female Onychoteuthis banksii for example, sheds its feeding tentacles on reaching maturity, and becomes flaccid and weak after spawning.[30][31]

Cardiovascular and excretory systems

The squid mantle cavity is a seawater-filled sac containing three hearts and other organs supporting circulation, respiration, and excretion.[32] Squid have a main systemic heart which pumps blood to the general circulatory system, and two branchial hearts which pump specifically to the gills.[32] The systemic heart consists of three chambers, a lower ventricle and two upper atria, which are all contractile. The blood contains the copper-rich protein, hemocyanin, which is used for oxygen transport at low ocean temperatures and low oxygen concentrations, and which makes the oxygenated blood a deep, blue color.[32] As systemic blood returns via two vena cavae to the branchial hearts, excretion of urine, carbon dioxide, and waste solutes occurs through outpockets (called nephridial appendages) in the vena cavae walls which enable gas exchange and excretion via the mantle cavity seawater.[32]


The majority are no more than 60 cm (24 in) long, although the giant squid may reach 13 m (43 ft).[33]

In 1978, sharp, curved claws on the suction cups of squid tentacles cut up the rubber coating on the hull of the USS Stein. The size suggested the largest squid known at the time.[34]

In 2003, a large specimen of an abundant[35] but poorly understood species, Mesonychoteuthis hamiltoni (the colossal squid), was discovered. This species may grow to 14 m (46 ft) in length, making it the largest invertebrate.[36] Squid have the largest eyes in the animal kingdom. The kraken is a legendary tentacled monster possibly based on sightings of real giant squid.

In February 2007, a New Zealand fishing vessel caught the largest squid ever documented, weighing 495 kg (1,091 lb) and measuring around 10 m (33 ft) off the coast of Antarctica.[37]


The eggs of squid are large for a mollusc, containing a large amount of yolk to nourish the embryo as it develops directly, without an intervening veliger larval stage. Cleavage is superficial and a germinal disc develops at the pole. During gastrulation, the margins of the germinal disc grow to surround the yolk, forming a yolk sac, which eventually forms part of the animal's gut. The dorsal side of the disc grows upwards and forms the embryo, with a shell gland on its dorsal surface, gills, mantle and eyes. The arms and funnel develop as part of the foot on the ventral side of the disc. The arms later migrate upwards, coming to form a ring around the funnel and mouth. The yolk is gradually absorbed as the embryo grows. Some juvenile squid live higher in the water column than do adults. Squids tend to be short-lived; Loligo for example lives from one to three years according to species, typically dying soon after spawning.[4]


Courtship in squid takes place in the open water and involves the male selecting a female, the female responding, and the transfer by the male of spermatophores to the female. In many instances the male may display to identify himself to the female and drive off any potential competitors.[38] The pair adopt a head-to-head position, and "jaw locking" may take place, in a similar manner to that adopted by some cichlid fish.[39] The heterodactylus of the male is used to transfer the spermatophore and deposit it in the female's mantle cavity in the position appropriate for the species; this may be adjacent to the gonopore or in a seminal receptacle.[4]

Human uses

Commercial fishing

According to the FAO, the cephalopod catch for 2002 was 3,173,272 tonnes (6.995867×109 lb). Of this, 2,189,206 tonnes, or 75.8 percent, was squid.[40] The following table lists the squid species fishery catches which exceeded 10,000 tonnes (22,000,000 lb) in 2002.

World squid catch in 2002[40]
Species Family Common name Catch
Loligo gahi or Doryteuthis gahi Loliginidae Patagonian squid 24,976 1.1
Loligo pealei Loliginidae Longfin inshore squid 16,684 0.8
Common squid nei[41] Loliginidae 225,958 10.3
Ommastrephes bartramii Ommastrephidae Neon flying squid 22,483 1.0
Illex argentinus Ommastrephidae Argentine shortfin squid 511,087 23.3
Dosidicus gigas Ommastrephidae Humboldt squid 406,356 18.6
Todarodes pacificus Ommastrephidae Japanese flying squid 504,438 23.0
Nototodarus sloanii Ommastrephidae Wellington flying squid 62,234 2.8
Squid nei[41] Various 414,990 18.6
Total squid 2,189,206 100.0
Photo of rings of breaded, fried squid
Fried calamari: breaded, deep-fried squid

As food

Squid form a major food resource and are used in cuisines around the world, notably in Japan where it is eaten as ika-somen, sliced into vermicelli-like strips; as sashimi; and as tempura.[42] Three species of Loligo are used in large quantities, L. vulgaris in the Mediterranean (known as Calamar in Spanish, Calamaro in Italian); L. forbesii in the Northeast Atlantic; and L. pealei on the American East Coast.[42] Among the Ommastrephidae, Todarodes pacificus is the main commercial species, harvested in large quantities across the North Pacific in Canada, Japan and China.[42]

In English-speaking countries, squid as food is often called calamari, adopted from Italian into English in the 17th century.[43] Squid are found abundantly in certain areas, and provide large catches for fisheries. The body can be stuffed whole, cut into flat pieces, or sliced into rings. The arms, tentacles, and ink are also edible; the only parts not eaten are the beak and gladius (pen). Squid is a good food source for zinc and manganese, and high in copper,[44] selenium, vitamin B12, and riboflavin.[45]

In literature and art

Giant squid have featured as monsters of the deep since classical times. Giant squid were described by Aristotle (4th century BC) in his History of Animals[46] and Pliny the Elder (1st century AD) in his Natural History.[47][48][49] The Gorgon of Greek mythology may have been inspired by squid or octopus, the animal itself representing the severed head of Medusa, the beak as the protruding tongue and fangs, and its tentacles as the snakes.[50] The six-headed sea monster of the Odyssey, Scylla, may have had a similar origin. The Nordic legend of the kraken may also have derived from sightings of large cephalopods; the science fiction writer Jules Verne told a tale of a kraken-like monster in his 1870 novel Twenty Thousand Leagues Under the Sea.[51]

In literature, H. G. Wells' short story "The Sea Raiders" featured a man-eating squid species Haploteuthis ferox.[52]

In biomimicry

Prototype chromatophores, mimicking the squid's adaptive camouflage, have been made by Bristol University researchers, using an electroactive dielectric elastomer, a flexible "smart" material that changes its colour and texture in response to electrical signals. The researchers state that their goal is to create an artificial skin that will provide rapid active camouflage.[53]

See also


  1. ^ Common name is however shared with Mastigoteuthidae.


  1. ^ Tanabe, K.; Hikida, Y.; Iba, Y. (2006). "Two Coleoid Jaws from the Upper Cretaceous of Hokkaido, Japan". Journal of Paleontology. 80 (1): 138–145. doi:10.1666/0022-3360(2006)080[0138:TCJFTU]2.0.CO;2.
  2. ^ a b Sanchez, Gustavo; Setiamarga, Davin H.E.; Tuanapaya, Surangkana; Tongtherm, Kittichai; Winkelmann, Inger E.; Schmidbaur, Hannah; Umino, Tetsuya; Albertin, Caroline; Allcock, Louise; Perales-Raya, Catalina; Gleadall, Ian; Strugnell, Jan M.; Simakov, Oleg; Nabhitabhata, Jaruwat (February 2018). "Genus-level phylogeny of cephalopods using molecular markers: current status and problematic areas". PeerJ. PeerJ. 6: e4331. doi:10.7717/peerj.4331.
  3. ^ Tanner, Alastair R.; Fuchs, Dirk; Winkelmann, Inger E.; Gilbert, M. Thomas P.; Pankey, M. Sabrina; Ribeiro, Ângela M.; Kocot, Kevin M.; Halanych, Kenneth M.; Oakley, Todd H.; da Fonseca, Rute R.; Pisani, Davide; Vinther, Jakob (March 2017). "Molecular clocks indicate turnover and diversification of modern coleoid cephalopods during the Mesozoic Marine Revolution". Proceedings of the Royal Society B: Biological Sciences. 284 (1850): 20162818. doi:10.1098/rspb.2016.2818.
  4. ^ a b c d e f g h i j k l m n o Ruppert, Edward E.; Fox, Richard, S.; Barnes, Robert D. (2004). Invertebrate Zoology, 7th edition. Cengage Learning. pp. 343–367. ISBN 978-81-315-0104-7.
  5. ^ Ifuku, S. (2014). "Chitin and chitosan nanofibers: preparation and chemical modifications". Molecules. 19 (11): 18367–80. doi:10.3390/molecules191118367. PMID 25393598.
  6. ^ Bonnaud, Laure; Lu, C. C.; Boucher-Rodoni, Renata (2006). "Morphological character evolution and molecular trees in sepiids (Mollusca: Cephalopoda): is the cuttlebone a robust phylogenetic marker?". Biological Journal of the Linnean Society. 89 (1): 139–150. doi:10.1111/j.1095-8312.2006.00664.x.
  7. ^ Johnson, W.; Soden, P. D.; Trueman, E. R. (1972). "A Study in Jet Propulsion: An analysis of the motion of the squid, Loligo vulgaris". Journal of Experimental Biology. 56 (1): 155–165.
  8. ^ Jabr, F. (2 August 2010). "Fact or Fiction: Can a Squid Fly Out of the Water?". Scientific American.
  9. ^ a b Cott 1940, p. 32.
  10. ^ a b c Young, R.; Roper, C. (March 1976). "Bioluminescent countershading in midwater animals: evidence from living squid". Science. 191 (4231): 1046–1048. doi:10.1126/science.1251214.
  11. ^ Gilmore, R.; Crook, R.; Krans, J. L. (2016). "Cephalopod Camouflage: Cells and Organs of the Skin". Nature Education. 9 (2): 1.
  12. ^ Cott 1940, p. 383.
  13. ^ a b Mäthger LM, Shashar N, Hanlon RT (2009). "Do cephalopods communicate using polarized light reflections from their skin?". J Exp Biol. 212 (14): 2133–40. doi:10.1242/jeb.020800. PMID 19561202.
  14. ^ a b Mäthger LM, Denton EJ, Marshall NJ, Hanlon RT (2009). "Mechanisms and behavioural functions of structural coloration in cephalopods". J R Soc Interface. 6 (Suppl 2): S149–63. doi:10.1098/rsif.2008.0366.focus. PMC 2706477. PMID 19091688.
  15. ^ Jones, B. W.; Nishiguchi, M. K. (2004). "Counterillumination in the Hawaiian bobtail squid, Euprymna scolopes Berry (Mollusca : Cephalopoda)" (PDF). Marine Biology. 144 (6): 1151–1155. doi:10.1007/s00227-003-1285-3. Archived (PDF) from the original on 2010-06-11.
  16. ^ Young, Richard Edward (1983). "Oceanic Bioluminescence: an Overview of General Functions". Bulletin of Marine Science. 33 (4): 829–845.
  17. ^ Cott 1940, p. 381.
  18. ^ Derby, Charles D. (December 2007). "Escape by Inking and Secreting: Marine Molluscs Avoid Predators Through a Rich Array of Chemicals and Mechanisms". The Biological Bulletin. 213 (3): 274–289. doi:10.2307/25066645. JSTOR 25066645.
  19. ^ Hanlon, Roger T.; Messenger, John B. (1998). Cephalopod Behaviour. Cambridge University Press. pp. 25–26. ISBN 978-0-521-64583-6.
  20. ^ Young, Richard E.; Michael Vecchione (2013). "Histioteuthidae Verrill, 1881". The Tree of Life Web Project. Retrieved 9 December 2018.
  21. ^ Walker, Matt (15 June 2009). "The cephalopods can hear you". BBC. Retrieved 2 April 2010.
  22. ^ Smith, Helena (5 June 2012). "Coordinated Hunting in Red Devils". Deep Sea News. Archived from the original on 6 June 2012. Retrieved 9 December 2018.
  23. ^ Young, R.E.; Vecchione, M.; Mangold, K.M. "Hectocotylus". Cephalopoda Glossary. Tree of Life Web Project. Retrieved 14 December 2018.
  24. ^ a b c d Arkhipkin, A. I.; Laptikhovsky, V. V. (2010). "Observation of penis elongation in Onykia ingens: implications for spermatophore transfer in deep-water squid". Journal of Molluscan Studies. 76 (3): 299–300. doi:10.1093/mollus/eyq019.
  25. ^ Walker, M. (7 July 2010). "Super squid sex organ discovered". BBC Earth News.
  26. ^ Clarke, M. R. (1986). A Handbook for the Identification of Cephalopod Beaks. Clarendon Press. ISBN 0-19-857603-X.
  27. ^ Miserez, A.; Li, Y.; Waite, H.; Zok, F. (2007). "Jumbo squid beaks: Inspiration for design of robust organic composites". Acta Biomaterialia. 3 (1): 139–149. doi:10.1016/j.actbio.2006.09.004. PMID 17113369.
  28. ^ Hanlon, Roger T.; Messenger, John B. (1998). Cephalopod Behaviour. Cambridge University Press. p. 48. ISBN 978-0-521-64583-6.
  29. ^ Godfrey-Smith, Peter (2 December 2016). "Octopuses and the Puzzle of Aging". The New York Times. Retrieved 12 December 2018.
  30. ^ Barratt, I. & Allcock, L. (2014). "Onychoteuthis banksii". The IUCN Red List of Threatened Species. 2014: e.T163375A1003448. doi:10.2305/IUCN.UK.2014-1.RLTS.T163375A1003448.en. Downloaded on 15 March 2018.
  31. ^ Bolstad, K.S. (2008). "Two New Species and a Review of the Squid Genus Onychoteuthis Lichtenstein, 1818 (Oegopsida: Onychoteuthidae) from the Pacific Ocean". Bulletin of Marine Science. 83 (3): 481–529.
  32. ^ a b c d Roger Hanlon; Mike Vecchione; Louise Allcock (1 October 2018). Octopus, Squid, and Cuttlefish: A Visual, Scientific Guide to the Oceans’ Most Advanced Invertebrates. University of Chicago Press. ISBN 022645956X. Retrieved 12 December 2018.
  33. ^ O'Shea, S. (2003). "Giant Squid and Colossal Squid Fact Sheet". The Octopus News Magazine Online.
  34. ^ Johnson, C. Scott "Sea Creatures and the Problem of Equipment Damage" United States Naval Institute Proceedings August 1978 pp. 106–107
  35. ^ Xavier, J. C.; Rodhouse, P. G.; Trathan, P. N.; Wood, A. G. (1999). "A Geographical Information System (GIS) Atlas of cephalopod distribution in the Southern Ocean". Antarctic Science. 11 (1): 61–62. doi:10.1017/S0954102099000097.
  36. ^ Anderton, Jim (22 February 2007). "World's largest squid landed in NZ". New Zealand Government.
  37. ^ "Microwave plan for colossal squid". BBC. March 22, 2007.
  38. ^ Arnold, John M. (1965). "Observations on the Mating Behavior of the Squid Sepioteuthis sepioidea". Bulletin of Marine Science. 15 (1): 216–222.
  39. ^ Jackson, George D.; Jackson, Christine H. (2004). "Mating and spermatophore placement in the onychoteuthid squid Moroteuthis ingens". Journal of the Marine Biological Association of the United Kingdom. 84 (4): 783–784. doi:10.1017/S0025315404009932.
  40. ^ a b Rodhouse, Paul G. (2005). "Review of the state of world marine fishery resources: Fisheries technical paper". World squid resources. FAO (457). ISBN 92-5-105267-0.
  41. ^ a b nei: not elsewhere included
  42. ^ a b c Alan Davidson (2014). Tom Jaine, ed. The Oxford Companion to Food (3rd ed.). Oxford: Oxford University Press. pp. 773–774. ISBN 0-19-967733-6.
  43. ^ "Calamari". Merriam-Webster. Retrieved 12 December 2018. Definition of calamari: squid used as food
  44. ^ Squid – Overview: Food Market Exchange – B2B e-marketplace for the food industry Archived March 27, 2010, at the Wayback Machine.
  45. ^ "California Market Squid". FishWatch. Retrieved 27 March 2017.
  46. ^ Aristotle. N.d. Historia animalium.
  47. ^ Ellis, R. 1998. The Search for the Giant Squid. Lyons Press (London).
  48. ^ Pliny the Elder. n.d. Naturalis historia.
  49. ^ The Search for the Giant Squid: Chapter One. The New York Times.
  50. ^ Wilk, Stephen R. (2000). Medusa:Solving the Mystery of the Gorgon. Oxford University Press. ISBN 019988773X.
  51. ^ Hogenboom, Melissa (12 December 2014). "Are massive squid really the sea monsters of legend?". BBC. Retrieved 27 July 2016.
  52. ^ Wells, H. G. (1896). "The Sea Raiders". The Literature Network. Retrieved 12 December 2018.
  53. ^ Culpan, Daniel (16 June 2015). "Squid-inspired 'skin' could lead to smart camouflage". Wired. Retrieved 16 December 2018.


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