July 5, 2002
Architeuthis - The Giant Squid
This is Genevieve Johnson speaking to you from the Odyssey in the Indian Ocean.
After salvaging what we believe may be the remains of a mature giant squid dropped by a sperm whale, we are anxiously waiting on genetic analysis that will determine the exact species. We are all, I must admit, hoping it is the legendary and highly elusive giant squid - Architeuthis.
Most of us have a perception of this creature, that was born of the many legends and myths that have so long surrounded it. However, the truth about this animal may be quite different. Inaccurate information regarding the giant squid is often found in popular literature. In reality, what is truly known comes only from records of dead or dying specimens and there is no conclusive evidence that anyone has ever seen a mature giant squid alive and healthy in its natural habitat. So what do scientists really know about this creature?
Architeuthis is undoubtedly large, but its reputation has almost certainly surpassed reality, with unsubstantiated claims of animals hundreds of feet long. Nevertheless, as far as is known, it is the largest invertebrate that has ever lived. The longest recorded specimen was about 60 feet (18 meters), with well over half its length coming from the two long tentacles that stretch out in front of a giant squid's body. The mantle may reach a length of 5 meters and an adult may weigh over a ton (1,000 kilograms.) With proportions such as these, Architeuthis rightly deserves its place in the record books, even if it doesn't justify the belief that it is a humongous monster.
Despite its sheer size, Architeuthis may not be particularly strong or fast. Unlike many other species of squid that must continually swim to keep from sinking, Architeuthis has the ability to remain motionless, suspended in the water column. That is because the group of squids to which it belong produce ammonium chloride, which is less dense than seawater. Architeuthis has many fluid-filled spaces containing ammonium chloride, which presumably means it can achieve neutral buoyancy. Such a passive buoyancy system is also one of several possible explanations for what brings dead or dying 'giant squid' to the surface.
The fins are not particularly strong or large, and are innervated with nerve fibres far smaller in diameter than the famous giant, single neurones found in other smaller, more common squid species. Thus, a picture begins to emerge of perhaps a relatively weak, slow-moving creature, rather than an aggressive, whale threatening monster.
The suckers are not excessively large nor do the suckers contain any hooks to help the squid adhere to the active prey it is trying to overcome. Some scientists suggest that giant squid may not attack large preyat all-that they lead more sedentary lives at great depths with no reason to approach the surface unless they are ill or dying. Others think this an unlikely scenario since it doesn't explain Architeuthis'
large, heavily muscled beak and massive, suckered arms. Such people point out that with such a robust body and flexibility and quick reflexes might easily make up for lack of speed. But inasmuch as no one has ever seen Architeuthis doing anything at all, conjecture about its strength and speed will remain unresolved until a live and healthy specimen can be observed.
Interestingly, most specimens have been caught at depths of between 200 - 500 meters (through entanglement-not by any fisher having figured out how to attract a giant squid to a lure). All such animals have been found to have empty stomachs. There is much speculation about this, and it is not helped by ignorance about both the vertical and the geographical distribution of Architeuthis. In part, this is due to uncertainties in the number of Architeuthis species.
Nothing is known about sexual behavior, little about development, and there is practically no data on growth rates or extent of growth. If we look at other squid species for hints as to these answers, we find that squid tend to specialize in high reproductive rates and short life cycles. All else being equal, as Abrahamson (1992) has pointed out: the more rapidly an animal can grow, the faster it can reduce the number and kinds of predators that are large enough to subdue it. With its supposed high growth rate, by the time… [Architeuthis] reaches adolescence, it is probably already too large to be eaten by anything other than a giant shark or a large toothed whale.
We know that Sperm whales and Architeuthis do meet regularly in battle, although it is probably far from an even match-the whale almost certainly having the upper hand. Sperm whales are often found with large sucker marks on their heads, which are thought to be made by Architeuthis But this has not been adequately substantiated, and size claims have sometimes been greatly exaggerated. (Roper & Boss, 1982.) One major confounding circumstance is that the size of the scarred rings that suckers create increases with the growth of the whale, and it is impossible to know when the mark was originally made.
It is likely that very little can be concluded based on the single fin portion we found, which presumably belonged to a very large squid. Although a lot of what is currently known is based on such bits and pieces of information, the truth will probably continue to emerge one small clue at a time, and the complete and true picture of Architeuthis will almost certainly be less exciting than the man-eating, ship-sinking, whale-wrestling monster portrayed in popular literature. However a complete picture may be a long way off, with the very nature of this creature almost precluding scientists from obtaining anything but dribs and drabs of the most rudimentary information.
Meanwhile, as the Odyssey crew continues to search for sperm whales, we keep a vigilant watch, in hopes of seeing the elusive Architeuthis alive in its natural environment.
Learn more about the squid fin the Odyssey crew found on the surface of the
ocean in 'Legends of the Deep'.
The National Museum of Natural History - Smithsonian Institution : http://www.mnh.si.edu
James C. Hunt. Octopus and Squid.
1996, Monteray Bay Aquarium Foundation. P. 57, 60, 61.
Mark Norman & Amanda Ried. A Guide to Squid, Cuttlefish & Octopuses of Australia.
2000, CSIRO & The Gould League of Australia. P. 44, 45.
Roger T. Hanlon & John B. Messenger. Cephalopod Behaviour.
1996, Cambridge University Press. P. 92, 166, 167, 168.
Roper, C.F.E., and K.J. Boss.
1982. The Giant Squid. Scientific American. P. 96 - 105.
Log by Genevieve Johnson