Animal Diversity Web

Ge­o­graphic Range

Giant squid are dis­trib­uted in all the oceans of the world, usu­ally in as­so­ci­a­tion with con­ti­nen­tal and is­land slopes. Con­cen­tra­tions of species found range from the North At­lantic Ocean, es­pe­cially New­found­land, Nor­way, north­ern British Isles and the oceanic is­lands of the Azores and Madeira; the South At­lantic in south­ern African wa­ters; the North Pa­cific around Japan, and the south­west­ern Pa­cific around New Zealand and Aus­tralia; cir­cum­global in the South­ern Ocean. Spec­i­mens are rare from trop­i­cal and high polar lat­i­tudes.(Forch 1998)

• Biogeographic Regions
• arctic ocean
  • native
• indian ocean
  • native
• atlantic ocean
  • native
• pacific ocean
  • native

Habi­tat

No one re­ally knows where giant squid live be­cause no one has seen one alive in its nat­ural habi­tat. Only re­cent re­search has in­di­cated where this habi­tat might be. It is in the deep sea, per­haps be­tween 200 and 1000 me­ters in depth, and it is pos­si­bly in as­so­ci­a­tion with the bot­tom of the sea rather than in mid-wa­ter. On the other hand, spec­i­mens that have been cap­tured in nets some­times come from mid-wa­ter.

Work done by Dr. Ole Brix, of the Uni­ver­sity of Bergen, in­di­cated the blood of squids does not carry oxy­gen very well at higher tem­per­a­tures. A squid will ac­tu­ally suf­fo­cate in warm water. Warm water will cause a giant squid to rise to the sur­face and not be able to get back down. So the giant squid are prob­a­bly more likely to be found in cooler water. (Forch 1998) (Ban­is­ter and Camp­bell 1985)

• Aquatic Biomes
• benthic

Phys­i­cal De­scrip­tion

The Ar­chi­teuthi­dae are the largest known cephalopods, the largest known mol­lusks and prob­a­bly the largest in­ver­te­brates ever known to exist in the oceans. Ar­chi­teuthi­dae have been recorded as long as 60 feet in total length, most of the spec­i­mens that have been found are re­ally in the 35-45 foot range. There are still many which range from about 20 to 30 feet in length. The total length in­cludes the body, the head, the arms, and the two long feed­ing ten­ta­cles. These feed­ing ten­ta­cles are much longer than the rest of the body. The heav­i­est an­i­mals weigh about a ton, but most of the time they are a thou­sand pounds or less.

These giant squid also have the largest eyes out of any an­i­mal in the world. The eyes of the giant squid can be as big as a human's head. Most deep-sea an­i­mals have very large eyes so they can gather the small amounts of light that are avail­able in the deep depths of the ocean. They might even be able to see bi­o­lu­mi­nes­cent light.

The Ar­chi­teuthi­dae posses two ten­ta­cles that av­er­age about 10-12 me­ters in length. These ten­ta­cles have many suck­ers on the tips, called clubs. The ten­tac­u­lar clubs are nar­row and have suck­ers, which are sub-spher­i­cal cups lined with sharp, finely ser­rated rings of chitin, in four lon­gi­tu­di­nal rows. These suck­ers cover only the inner sur­face of the arms and ten­ta­cles. These ten­tac­u­lar clubs are di­vided into dis­tinct car­pus, manus and dacty­lus. The manus has en­larged suck­ers along me­dial two rows. The suck­ers on the ten­ta­cles, and the arms, are not known to be any big­ger than about five to five and a half cen­time­ters. The carpal re­gion has a dense clus­ter of suck­ers, in six to seven ir­reg­u­lar, trans­verse rows.

The Ar­chi­teuthi­dae also have fins that are pro­por­tion­ally small, ovoid, and with­out free an­te­rior lobes. The fins at the rear of the man­tle, are used to help the squid move by gen­tle, rhyth­mic pulses of water pushed out of the man­tle cav­ity through­out the fun­nel.

They also have eight arms with suck­ers in two lon­gi­tu­di­nal rows. At the end of the arms they have a par­rot-like beaks at the base. An­other char­ac­ter­is­tic of the squid is that they have buc­cal con­nec­tives that at­tach to the dor­sal bor­ders of arms.

Giant squid con­tain the dark, sepia-col­ored ink that we as­so­ci­ate with the smaller, more fa­mil­iar squid.

They have the two, very large gills rest­ing in­side the man­tle cav­ity. The squid are able to breath and move quickly by ex­pand­ing the man­tle cav­ity by con­tract­ing sets of mus­cles within the man­tle. The water fills the ex­panded space, the mus­cles relax, and the elas­tic man­tle then snaps back to a smaller size, jet­ting water out through the fun­nel. The jet of water closes the flaps on ei­ther side of the squid's head so water can exit only through the fun­nel.

The ner­vous sys­tem of the squids are very ex­ten­sive and they even also have a com­plex brain. For this rea­son they are under ex­ten­sive re­search. The cir­cu­la­tory sys­tem is closed which is a dis­tinct char­ac­ter­is­tic of the squid.(Port­ner, et al 1994) (Forch 1998)

• Other Physical Features
• ectothermic
• bilateral symmetry

Re­pro­duc­tion

The re­pro­duc­tion of Ar­chi­teuthis is not well known. Hy­pothe­ses are based on ob­ser­va­tions of the sex­ual char­ac­ter­is­tics in dead Ar­chi­teuthis and from the knowl­edge of other squid

Fe­males pro­duce enor­mous quan­ti­ties of whitish to cream-col­ored eggs, about .5-1.4 mm long and .3-.7 mm wide, de­pend­ing on the stage of their ma­tu­rity. One fe­male had over 5000 gm(over 11 pounds) of eggs in her ovary, well in ex­cess of a mil­lion eggs. As in most oe­gop­sids, fe­males have a sin­gle me­dian ovary in the pos­te­rior end of the man­tle cav­ity, paired, con­vo­luted oviducts along with ma­ture eggs pass, then exit through the ovid­u­cal glands, and large nida­men­tal glands that pro­duce quan­ti­ties of gelati­nous ma­te­r­ial. Whether the eggs are laid into a large gelati­nous ma­trix, as in most of the large oceanic squids or are re­leased in­di­vid­u­ally, is un­known, al­though the large nida­men­tal glands sug­gest the for­mer method.

Males tend to reach sex­ual ma­tu­rity at a smaller size than do fe­males. The two ven­tral arms are re­ported to be mod­i­fied into trans­fer­ing the sper­matophores to the fe­male. As in most other cephalopods, the sin­gle, pos­te­rior testis pro­duces sperm that move into a com­plex sys­tem of glands that man­u­fac­ture the sper­matophores. These are stored in the elon­gate sac, or Need­ham's sac from which they are ex­pelled dur­ing mat­ing. The Need­ham's sac of fully ma­ture males is packed with hun­dreds of sper­matophores. Need­ham's sac ter­mi­nates in the penis. The penis is so elon­gate that it ex­tends an­te­ri­orly be­yond the man­tle open­ing. While mat­ing has not been ob­served and the exact role of the penis is un­cer­tain, some fe­males have been found with sper­matan­gia, the sperm-con­tain­ing sacs of the sper­matophore, em­bed­ded in the tis­sue around the bases of the arms and the head.

Cephalopods are known to be very fast grow­ing an­i­mals. Some species of small, shal­low water forms reach sex­ual ma­tu­rity in 6-8 months, and most species about which growth, age and ma­tu­rity data are avail­able reach re­pro­duc­tive ca­pac­ity within 12-18 months. Many of the spec­i­mens of Ar­chi­teuthis that have been re­cov­ered have been ma­ture, es­pe­cially the fe­males. But the age at ma­tu­rity of Ar­chi­teuthis is not known with cer­tan­ity. One study sug­gests that adult size is at­tained within 3 years. Even at the rapid growth rate ex­pected in cephalopods, the at­tain­ment of a mass of 500 kg or more in fewer than 3 years is im­pres­sive.

(Nesis 1987)

Be­hav­ior

Since sci­en­tists have never ob­served giant squid alive in their nat­ural habi­tat, they can­not say what its be­hav­ior is like. There is no way to know for sure how Ar­chi­teuthis in­di­vid­u­als in­ter­act with each other. One thing that sci­en­tist have hy­poth­e­sized is that Ar­chi­teuthis may be soli­tary hunters. They be­lieve this be­cause no two Ar­chi­teuthis have ever been caught in fish­ing nets to­gether. (Forch 1998)

Food Habits

For many years, no­body knew what the giant squid uti­lized for food. This is be­cause they have never re­ally been ob­served in the wild. Some re­cent stud­ies on dead in­di­vid­u­als have shown that giant squid eat deep-sea fishes, such as or­ange ruffie, and hokie. They also eat other types of deep-sea squids, but not Ar­chi­teuthis, the giant squid.

As large as these an­i­mals are, they would prob­a­bly be able to cap­ture al­most any­thing, maybe even whales(see com­ments)! They cap­ture their prey by using their two long feed­ing ten­ta­cles. The ten­ta­cles are shot out to grip the prey. The suck­ers on the tips of ten­ta­cles grab hold of the prey and the ten­ta­cles con­tract, bring­ing the prey to the arms. The arms then fur­ther sub­due the prey, pulling it to the strong, sharp beaks. The beaks are op­er­ated by a mas­sive set of mus­cles that allow them to bite through just about any­thing the squid might cap­ture. But the giant squid's bite-sized pieces of food need fur­ther shred­ding be­fore being di­gested. The tongue is equipped with an organ known as the radula, which is loaded with rows of small, file-like teeth. The radula fur­ther shreds the meal be­fore the tongue pushes it down the esoph­a­gus to the di­ges­tive or­gans.

There are very few preda­tors of the adult giant squid. The best and prob­a­bly only one is the sperm whale. As ba­bies and ju­ve­niles, they have many peda­tors, mostly deep sea fishes. Once giant squid get be­yond a cer­tain size, they have out­grown the size of most of their po­ten­tial preda­tors. Sperm whales grow to 40-50 feet in length, but they weigh 30-40 tons. So even though a giant squid is huge, it is not big enough to es­cape or to fight with a sperm whale. Most of the time the sperm whale wins. This is ev­i­dent in the num­ber of giant squid found in the stom­ach of the sperm whale. (Forch 1998) (Ban­is­ter and Camp­bell 1985)

Eco­nomic Im­por­tance for Hu­mans: Pos­i­tive

Since not much is known, it is hard to tell how im­por­tant it is to hu­mans. It could be an es­sen­tial part of the food chain, and if it is dis­rupted it could hurt the whales, for which we do have uses. The squid and other cephalopods have a very dis­tinct and elab­o­rate ner­vous sys­tem and brain. The giant squid could help us un­der­stand and learn more about ner­vous sys­tems, maybe even ours. (Nesis 1987, Gilbert, et al 1990)

Eco­nomic Im­por­tance for Hu­mans: Neg­a­tive

As of right now, there re­ally are no ad­verse ef­fects on hu­mans. We just re­cently found out it ex­isted! The only minor prob­lem it pre­sents is that it can get en­tan­gled in fish­ing nets, but that it­self is not a se­ri­ous prob­lem. (Nesis 1987)

Con­ser­va­tion Sta­tus

The num­ber of in­di­vid­u­als of this species is un­known.(Forch 1998)

• IUCN Red List

  No special status

• US Federal List

  No special status

• CITES

  No special status

Other Com­ments

Since few of these species have been seen alive, there are many sto­ries, myths, and mys­ter­ies about the giant squid, and often these are as­so­ci­ated with dan­ger. The giant squid has even been called a sea mon­ster. New tech­nol­ogy will likely en­able us to not only look for and hope­fully find the giant squid, as well as ex­plore and dis­cover in the deep-sea habi­tat.

Con­trib­u­tors

Jer­rod Vaughan (au­thor), South­west­ern Uni­ver­sity, Stephanie Fab­ri­tius (ed­i­tor), South­west­ern Uni­ver­sity.

Ref­er­ences

Ban­is­ter, K., A. Camp­bell. 1985. The En­cy­clo­pe­dia of Aquatic Life. New York, NY: Facts on File.

Forch, E. 1998. The Ma­rine Fauna of New Zealand: Cephalopoda: Oe­gop­sida: Ar­chi­teuthi­dae (Giant Squid). Welling­ton: Na­tional In­sti­tute of Water and At­mos­pheric Re­search.

Gilbert, D., W. Adel­man, J. Arnold. 1990. Squid as Ex­per­i­men­tal An­i­mals. New York, NY: Plenum Press.

Nesis, K. 1987. Cephalopods of the World: Squids, Cut­tle­fishes, Oc­to­puses and Al­lies. Nep­tune, N.J.: T.F.H Pub­li­ca­tions.

Port­ner, H., R. O'Dor, D. Macmil­lan. 1994. Phys­i­ol­ogy of Cephalo­pod Mol­luscs. Switzer­land: Gor­don and Breach Pub­lish­ers.