Giant squid
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Architeuthis dux |
Giant squid, once believed to be mythical creatures, are marine mollusks of the class Cephalopoda, represented by as many as eight species of the genus Architeuthis. They are deep-ocean dwelling squid that can grow to a tremendous size: recent estimates put the maximum size at 10 m (34 ft) for males and 13 m (44 ft) for females from caudal fin to the tip of the two long tentacles (second only to the Colossal Squid at an estimated 14 m, one of the largest living organisms). The mantle length, though, is only about 2 m (7 ft) in length (more for females, less for males), and the length of the squid excluding its tentacles is about 5 m (16 ft). There were reported claims of specimens of up to 20 m (66 ft), but none had been scientifically documented. In September 2005 the first images of live giant squid in their natural habitat were released by Japanese researchers.
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Biology
Despite their great length, giant squid are not particularly heavy when compared to their chief predator, the Sperm Whale, because the majority of their length is taken up by their eight arms and two tentacles. The weights of recovered specimens have been measured in hundreds, rather than thousands, of kilograms. Post-larval juveniles have been discovered in surface waters off New Zealand, and there are plans to capture more such juveniles and maintain them in an aquarium in an attempt to learn more about the creature's biology and habits.
The reproductive cycle of the giant squid is still a great mystery, but what has been learned so far is both bizarre and fascinating; male giant squid are equipped with a prehensile spermataphore-depositing tube, or Hectocotylus, of over 90 cm (three feet) in length, which extends from inside the animal's mantle and apparently is used to inject sperm-containing packets into the female squid's arms — how exactly the sperm then is transferred to the egg mass is a matter of much debate, but the recent recovery in Tasmania of a female specimen having a small subsidiary tendril attached to the base of each of its eight arms could be a vital clue in the solution of this enigma.
Giant squid possess the largest eyes of any living creature ever, over 30 cm (one foot) in diameter, and their arms are equipped with hundreds of suction cups in total; each is mounted on an individual "stalk" and equipped around its circumference with a ring of sharp teeth to aid the creature in capturing its prey by firmly attaching itself to it both by suction and perforation. The size of these suction cups can vary from 2 to 5 cm in diameter (one to two inches), and it is not uncommon to find their circular scars on the head area of sperm whales that have fed — or attempted to feed — upon giant squid. The only other known predator of the adult giant squid is the Pacific sleeper shark, found off Antarctica, but it is not yet known whether these sharks actively hunt the squid, or are simply scavengers of squid carcasses. Because sperm whales are skilled at locating giant squid, scientists have attempted to conduct in-depth observations of sperm whales in order to study squid.
One of the more unusual aspects of giant squid (as well as some other species of large squid) is their reliance upon the low density of ammonia in relation to seawater to maintain neutral buoyancy in their natural environment, as they lack the gas-filled swim bladder that fish use for this function; instead, they use ammonia (in the form of ammonium chloride) in the fluid of their flesh throughout their bodies. This makes the giant squid unfit for human consumption, although sperm whales seem to be attracted by (or are at least tolerant of) its taste.
Like all cephalopods they use special organs called statocysts to sense their orientation and motion in the water. The age of giant squids can be estimated by "growth rings" in the statocyst's "statolyth" much like counting tree rings. Much of what is known about these animals come from estimates based on these, and from undigested beaks found in sperm whale stomachs.
Timeline
One of the first pieces of real evidence of the existence of a giant squid was found in 1873 when one attacked a minister and a young boy in a dory in Bell Island, Newfoundland. A giant squid specimen washed ashore in Glover's Harbour, Newfoundland on November 2, 1878. Its body was 6.1m (20 ft) long, and one of its tentacles measured 10.7m (35 ft) long and it was estimated as weighing 2.2 tonnes.
The period (1870 - 1880) in Newfoundland saw the greatest known concentration of beached giant squid to date: 50 or more individual squid carcasses washed up on the shores of Newfoundland during this decade. An almost equal number of strandings also occurred in New Zealand during the late nineteenth century. Although strandings continue to occur sporadically throughout the world, the late nineteenth century mass strandings at Newfoundland and New Zealand have not yet been repeated. It is not known exactly why giant squid become stranded on shore, but it is possible that a periodic though temporary alteration of the distribution of the deep, cold water where the squid live might be the cause. Many scientists who have studied squid mass strandings believe that they are cyclical and predictable, but the length of time between strandings is not yet known. A period of 90 years between mass strandings has been proposed by Frederick Aldrich, an "Architeuthis" specialist, who used this value to correctly predict a relatively small stranding that occurred between 1964 and 1966. By and large, however, squid strandings remain a mystery.
The search for a live Architeuthis specimen includes attempts to find live young, including larvae. Approximately 65 specimens, one-fifth of all the giant squid ever found, have been found in the waters off Newfoundland; the last in December 2004.
Recently, a possibly even more massive squid, the little known Colossal Squid Mesonychoteuthis hamiltoni, has been described in more detail due to a new specimen being found. It is an inhabitant of Antarctic waters, and unlike the giant squid, relies upon both claw-like hooks and suction cups on its arms and tentacles to capture prey. Although its body may be of greater size than the giant squid, its tentacles appear to be considerably shorter in length; it is also believed to be responsible for scars on the backs of sperm whales, through the use of hooks on its tentacles.
On September 27, 2005, scientists released over 500 photographs taken at the end of October 2004. These were the first photographs ever captured of a live giant squid in its natural habitat. The photo sequence, taken at a depth of 900 m (nearly 3000 ft) off Japan's Ogasawara Islands, shows the squid homing in on the baited line and enveloping it in "a ball of tentacles." Researchers were able to locate the likely general location of giant squid by closely tailing the movements of sperm whales. Per Tsunemi Kubodera, of the National Science Museum of Japan in Tokyo, "we knew that they fed on the squid, and we knew when and how deep they dived, so we used them to lead us to the squid." Kubodera and Kyoichi Mori of the Ogasawara Whale Watching Association reported their observations in the journal Proceedings of the Royal Society.
Among other things, the observations demonstrate actual hunting behaviors of adult Architeuthis, a subject on which there had been much speculation. The photographs showed an aggressive hunting pattern by the baited squid, leading to it impaling a tentacle on the bait ball's hooks. This may disprove the theory that the giant squid is a drifter which eats whatever floats by, rarely moving so as to conserve energy. It seems that the species has a much more belligerent feeding technique.
Giant squid in culture
Tales of giant squid have been common among mariners since ancient times, and may have led to the Norwegian legend of the kraken, a tentacled sea monster as large as an island capable of engulfing and sinking any ship. However, it is thought to be impossible for a giant squid to lift its tentacles from the water. Eyewitness accounts of other sea monsters like the sea serpent are also thought to be mistaken interpretations of giant squid.
- Captain Nemo's submarine, the Nautilus, fights a giant squid in Twenty Thousand Leagues Under the Sea.
- James Bond fights a giant squid in Ian Fleming's book, Dr. No.
- A giant squid also dwells in the lake at Hogwarts in the Harry Potter series of books.
- A giant squid is a key player in Michael Crichton's novel Sphere.
- Jaws' author Peter Benchley's novel Beast features a giant squid terrorizing a fishing village.
- A giant squid fighting a sperm whale is shown on the album cover of They Might Be Giants' Apollo 18.
- A giant squid acts as a minor character in Charles Sheffield's novel The Web Between the Worlds.
- In J.R.R. Tolkien's Lord of the Rings: The Fellowship of the Ring, the Fellowship come up against the Watcher in the Water, a monster that lurks in the waters of the Sirannon, beneath the western walls of Moria. Although Tolkien's description is vague, the creature is frequently depicted as a giant squid or kraken with varying (often exaggerated) numbers of tentacles, and appeared as such in the 2001 film.
- River Moth, which flows through author Jeff VanderMeer's fictional city Ambergris, is inhabited by a giant squid.
- Chapter 59 ("Squid") of Moby-Dick details the Pequod's encounter with a giant (or perhaps colossal) squid
- H.P. Lovecraft is known to have squid like creatures in his Cthulhu mythos.
- In Command & Conquer: Red Alert 2, Giant Squids are one of the most powerful naval units in the Soviet arsenal.
Species
The broadest list of species is as follows:
- Atlantic Giant Squid, Architeuthis dux
- Architeuthis hartingii *
- Architeuthis japonica *
- Architeuthis kirkii *
- Architeuthis martensi
- Architeuthis physeteris
- Southern Giant Squid, Architeuthis sanctipauli
- Architeuthis stockii *
However, it is likely that not all of these are distinct species. The species listed above with an asterisk (*) are questionable and need further study to determine if they are a valid species or a synonym.
See also
References
- Ellis, R. (1998) The Search for the Giant Squid. Lyons Press. London.
- National Geographic Video: "Sea Monsters"
- Aldrich, F. A., and Brown, E. L. 1967. The Giant Squid in Newfoundland. The Newfoundland Quarterly. Vol. LXV No. 3. p. 4-8.
- "New giant squid predator found." Accessed October 6, 2005.
External links
- Face to face at last with Captain Nemo's old foe
- Holy Squid! Photos Offer First Glimpse of Live Deep-Sea Giant
- Giant Squid
- Giant Squid captured on camera, 2005
- TONMO.com's fact sheet for giant and colossal squids
- Encounters with Giant Squid
- 15 January, 2003, Giant squid 'attacks French boat'
- Cephalopod taxonomy (as PDF)
- Report in Royal Society
- Slate: Giant Squid, Where Are You?
- CephBase: Architeuthis
