Giant Squid the facts
Where you need to go, if you are interested in the Yeti
Giant squid, once believed to be mythical creatures, are squid of the Architeuthidae family, represented by as many as eight species of the genus Architeuthis. They are deep-ocean dwelling animals that can grow to a tremendous size: recent estimates put the maximum size at 13 m (43 ft) for females and 10 m (33 ft) for males from caudal fin to the tip of the two long tentacles (second only to the colossal squid at an estimated 14 m (46 ft), one of the largest living organisms). The mantle 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 have been claims reported of specimens of up to 20 m (66 ft), but no animals of such size have been scientifically documented.On September 30, 2004, researchers from
the National Science Museum of Japan and the Ogasawara Whale Watching Association
took the first images of a live giant squid in its natural habitat. Several of
the 556 photographs were released a year later. The same team successfully filmed
a live giant squid for the first time on December 4, 2006.
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.
Little is known regarding the reproductive cycle of the giant squid, but what has been learned is that the male of the species has a prehensile spermatophore-depositing tube, or penis, of over 3 ft (90 cm) 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 — the means by which the sperm is transferred to the egg mass is a matter of much debate, but a recovery in Tasmania of a female specimen with a small subsidiary tendril attached to the base of each of its eight arms could be a vital clue to resolving the question. The giant squid lacks the hectocotylus used for reproduction in many other cephalopods.
Giant squid possess the largest eyes of any living creature—with the possible exception of those of the colossal squid—the eye being over 1 ft (30 cm) in diameter. The tentacles are equipped with hundreds of suction cups, each 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 thereto by both suction and perforation. The size of the suction cups varies from 2 to 5 cm in diameter (1 to 2 in), and it is common 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. Owing to the fact that sperm whales are skilled at locating giant squid, scientists have attempted to conduct in-depth observations of sperm whales in order to study squid.
Tentacular club of Architeuthis
The fabled underwater encounter between the
sperm whale and giant squid, from a diorama at the American Museum of Natural
History.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, making it taste not unlike salmiakki. This makes the giant squid
unattractive for general human consumption, although sperm whales seem to be attracted
by (or are at least tolerant of) its taste.
As with all cephalopods, giant
squid have special organs called statocysts to sense their orientation and motion
in the water. The age of a giant squid can be determined by "growth rings"
in the statocyst's "statolith", analogous to determining the age of
a tree by counting its rings. Much of what is known about giant squid is based
upon estimates of the growth rings and from undigested beaks found in the stomachs
of sperm whales.
The "nearly perfect specimen" that was beached
alive in Trinity Bay, Newfoundland, on September 24, 1877. This specimen measured
39.5 ft in total length, close to the maximum known size of giant squid.Giant
squid size, and particularly total length, has often been misreported and exaggerated.
Reports of specimens reaching or even exceeding 18 m (59 ft) in length are widespread,
but no animals approaching this size have been scientifically documented. According
to giant squid expert Dr. Steve O'Shea, such lengths were likely achieved by great
lengthening of the two long feeding tentacles, analogous to stretching elastic
bands.
Based on the examination of 105 specimens as well as beaks recovered from Sperm Whales, the giant squid is not known to attain a mantle length (ML) in excess of 2.25 m (7.4 ft). Including the head and arms, but excluding the tentacles, Architeuthis very rarely exceeds 5 m (16 ft) in length.Maximum total length, when measured relaxed post mortem, is estimated at 13 m (43 ft) for females and 10 m (33 ft) for males from caudal fin to the tip of the two long tentacles.
Giant squid exhibit sexual dimorphism. Maximum weight is estimated at 275 kg (606 lb) for females and 150 kg (331 lb) for males.
Worldwide giant squid
distribution based on recovered specimens.
Giant squid, measuring 7 m, encased
in a block of ice at the Melbourne Aquarium.
A giant squid's tentacles with
a human hand for size comparison.The taxonomy of the giant squid, as with many
cephalopod genera, has not been entirely resolved. Lumpers and splitters may propose
as many as eight species or as few as one. The broadest list is:
Architeuthis
dux, "Atlantic Giant Squid"
Architeuthis hartingii
Architeuthis
japonica
Architeuthis kirkii
Architeuthis martensi
Architeuthis physeteris
Architeuthis sanctipauli, "Southern Giant Squid"
Architeuthis
stockii
It is probable that not all of these are distinct species. No genetic
or physical basis for distinguishing between the named species has been proposed,
as evidenced by the placenames — of location of specimen capture — used
to describe several of them. The rarity of observations of specimens and the extreme
difficulty of observing them alive, tracking their movements, or studying their
mating habits militates against a complete understanding.
In the 1984 FAO Species Catalogue of the Cephalopods of the World, C.F.E. Rope, M.J. Sweeney and C.F. Nauen wrote:
"Many species have been named in the sole genus of the family Architeuthidae, but they are so inadequately described and poorly understood that the systematics of the group is thoroughly confused."
Kir Nazimovich Nesis (1982, 1987) considers that only three species are likely to be valid.
In 1991, Frederick Aldrich of the Memorial University of Newfoundland wrote:
"I reject the concept of 20 separate species, and until that issue is resolved, I choose to place them all in synonymy with Architeuthis dux Steenstrup."
In a letter to Richard Ellis dated June 18, 1996, Martina Roeleveld of the South African Museum wrote:
"So far, I have seen nothing to suggest that there might be more than one species of Architeuthis."
In Cephalopods: A World Guide (2000), Mark Norman writes the following:
"The number of species of giant squid is not known although the general consensus amongst researchers is that there are at least three species, one in the Atlantic Ocean (Architeuthis dux), one in the Southern Ocean (A. sanctipauli) and at least one in the northern Pacific Ocean (A. martensi)."
Steenstrup suggested
that 16th century illustrations of sea monks could be interpreted as giant squidTales
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. Japetus Steenstrup, the describer
of Architeuthis, suggested a giant squid was the species described as a sea monk
to the Danish king Christian III c.1550. The Lusca of the Caribbean and Scylla
in Greek mythology may also derive from giant squid sightings. Eyewitness accounts
of other sea monsters like the sea serpent are also thought to be mistaken interpretations
of giant squid.
The Alecton attempts to capture a giant squid in 1861Steenstrup
produced a number of papers on giant squid in the 1850s. He first used the term
"Architeuthis" in a paper in 1857. A portion of a giant squid was secured
by the French gunboat Alecton in 1861 leading to wider recognition of the species/genus
in the scientific community. Between 1870 and 1880, large numbers of strandings
occurred on the shores of Newfoundland. For example, a specimen washed ashore
in Thimble Tickle Bay, Newfoundland on November 2, 1878 was 6.1 m (20 ft) long
(mantle length), and one of its tentacles measured 10.7 m (35 ft) long and it
was estimated as weighing 2.2 tonnes. In 1873 a squid "attacked" a minister
and a young boy in a dory in Bell Island, Newfoundland.
Giant squid
from Logy Bay, Newfoundland in Reverend Moses Harvey's bathtub, November/December,
1873Large numbers of strandings also occurred in New Zealand during the late nineteenth
century. Although strandings continue to occur sporadically throughout the world,
the high frequency of strandings at Newfoundland and New Zealand in the late nineteenth
century 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.
Poster issued in 1988 by
Frederick Aldrich of the Memorial University of Newfoundland. Rewards were offered
for public cooperation in obtaining giant squid specimens.The search for a live
Architeuthis specimen includes attempts to find live young, including larvae.
Larval Architeuthis closely resemble larvae of Nototodarus and Moroteuthis, with
distinctive characteristics being the shape of the mantle attachment by the head,
the tentacle suckers, and the beaks. 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.
On September 30, 2004, Tsunemi Kubodera (National Science Museum of Japan) and Kyoichi Mori (Ogasawara Whale Watching Association) succeeded in taking history's first images of a live adult giant squid. Their teams had worked together for nearly two years to accomplish this. They used a five-ton fishing boat and only two crew members. The images were created on their third trip to a known Sperm Whale hunting ground 600 miles (970 km) south of Tokyo, where they had dropped a 3,000 ft (900 m) line baited with squid and shrimp. The line also held a camera and a flash. After over twenty tries that day, a 26-foot (8 m) giant squid attacked the lure and snagged its tentacle. It took the squid over four hours to break free, during which time the camera took over 500 photos. These were the first photographs ever captured of a live giant squid in its natural habitat. The squid left behind, attached to the lure, an 18-foot (5.5 m) tentacle. Later DNA tests confirmed the animal as a giant squid.
On September 27, 2005, Kubodera and Mori released the photos to the world. The photo sequence, taken at a depth of 900 m (nearly 3,000 ft) off Japan's Ogasawara Islands, shows the squid homing in on the baited line and enveloping it in "a ball of tentacles." The researchers were able to locate the likely general location of giant squid by closely tailing the movements of Sperm Whales. According to Kubodera, "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 Mori reported their observations in the journal Proceedings of the Royal Society.
One of the series
of images of a live giant squid taken by Kubodera and Mori in 2004.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.
In December 2005, the Melbourne Aquarium in Australia paid AUD$100,000 for the intact body of a giant squid, preserved in a giant block of ice, which had been caught by fishermen off the coast of New Zealand's South Island earlier in the year.
Still image from the first video of a live adult giant squid, filmed on December
4, 2006 by researchers from the National Science Museum of Japan led by Tsunemi
Kubodera.In early 2006, another giant squid, later named "Archie", was
caught off the coast of the Falkland Islands by a trawler. It measured 8.62 m
(28 ft) and was then sent to the Natural History Museum in London for study and
preservation. It was put on display on March 1, 2006 at the Darwin Centre. Most
giant squid specimens tend to be those that have washed up dead on beaches, or
been retrieved from the stomach of dead sperm whales; they tend to be in quite
poor condition. The find of such a large, complete specimen is extremely rare.
Giant squid researchers undertook a painstaking process to preserve the giant creature, which is now on show in a 9 m (30 ft) long glass tank. The first stage was to defrost it, after it spent the trip back to England on ice aboard the trawler. This thawing took about four days. The major difficulty was then the body of the animal — or the mantle. Thawing the thick mantle took much longer than the comparatively thin tentacles. To prevent the tentacles from rotting, scientists bathed the mantle in water, while covering the tentacles in ice packs, after which they injected the squid with a formol-saline solution to prevent rotting.
The squid now resides in a glass tank, filled to the brim with preservative solution, and is one of 22 specimens that can be seen as part of the behind-the-scenes Darwin Centre tour of the Natural History Museum.
On December 4, 2006, an adult giant squid was finally caught on video by Kubodera near the Ogasawara Islands, 1,000 km (620 miles) south of Tokyo. It was a small female about 3.5 m (11 ft 6 in) long and weighing 50 kg (110 lb). It was pulled aboard the research vessel but died in the process.
As of 2004, almost 600 giant squid specimens have been reported.
An illustration from the original edition of Twenty Thousand
Leagues Under the Sea depicting a giant squid.Main articles: Giant squid in culture
and Kraken in popular culture
The elusive nature of the giant squid and its
terrifying appearance have firmly established its place in the human imagination.
Representations of the giant squid have been known from early legends of the Kraken
through books such as Moby-Dick and Twenty Thousand Leagues Under the Sea to modern
animated television programs.
In particular, the image of a giant squid
locked in battle with a Sperm Whale is a common one, although the squid is, in
fact, the whale's prey and not an equal combatant.