⇧ [VIDÉO] You might also like this partner content (after ad)
The giant squids (Architeuthis dux), these fascinating cephalopods that have nourished myths and legends over the centuries, are among the most difficult animals to observe and study on Earth. These “elusive” giants notably inhabit the abyssal depths, areas less known to man than the surface of the Moon. The rare information that scientists have been able to extract comes mostly from carcasses of squid washed up on the beaches or from specimens accidentally caught in the nets of fishermen. Extremely rare fact: one of them was found stranded, but alive, last Thursday on the beach of Ugu in Obama, west of Japan. The 3.35 meter giant was then transported to the nearest aquarium in Sakai, in order to be studied more closely.
This specimen is probably the first giant squid to be captured alive. Although they are the largest invertebrates on Earth after (perhaps) the colossal squids (Mesonychoteuthis hamiltoni), observations of these cephalopods are very rare, because those that have been found so far lived up to more than 1300 meters deep. They may even be found even deeper in the abyss, but data on these inconspicuous marine animals is so scarce that scientists do not yet know their precise geographical distribution.
Their entire anatomy and physiology makes giant squid particularly adapted to the extreme conditions of the mesopelagic (between 200 and 1000 m depth) and bathypelagic (between 1000 and 4000 m depth) zones. Since from only 200 m the sunlight already hardly reaches the area, these gigantic cephalopods live in total darkness and easily withstand crushing pressures of up to 130 bar as well as cold temperatures. (not exceeding 4°C).
Finding them this far on the surface is then not only very unusual, but also often fatal for these creatures accustomed to the depths. Even if the specimen captured in Japan was miraculously found alive, there is little chance that it will survive for long in an aquarium that is too narrow, too lighted and too high in relation to its natural environment, unless perhaps d artificially create the right conditions there, which is not easy either.
Grow out of sight
The largest giant squid observed by scientists was nearly 13 meters long and about a ton, according to Smithsonian experts. Although the species lives in environments that are difficult to access (complicating observations), researchers from the National Science Museum of Japan, the Japanese public television channel NHK and the Discovery Channel had the incredible opportunity to film such a cephalopod in its environment. natural, in 2012. The colossus (7 meters in this case) has apparently already been filmed in 2006, attracted by a bait judiciously placed under a research vessel, off the Ogasawara Islands.
However, it should be noted that reported sizes often tend to be exaggerated, sightings being so rare, especially if the specimen is seen alive. Furthermore, when collecting data on squid washing up on beaches or dying on the surface of the water, the carcasses are often in poor condition, as they have already been consumed by other marine animals, or are also swollen with water (which can make them taller and wider).
In addition, for measurements and estimates, scientists rely on measurements of the mantle (the upper part of the horn-shaped squid), because the tentacles are often detached from the carcasses. The longest mantle recorded was no more than 2.25 m, and the largest reported total size (from mantle to tentacles) is 13 m. However, according to a new measurement technique based on the beak, scientists estimate that the animal could probably reach 20 m (larger than the colossal squid).
The spectacular dimensions of the giant squid are probably explained by the absence of predators, apart from the sperm whale (Physeter macrocephalus), whom he may come across from time to time. Additionally, some cephalopods, probably including giant squids, are known to possess a rare form of intelligence. This intelligence and cunning, combined with the thousands of suckers, eight arms and two long main tentacles, make it a particularly effective predator. Its eyes (the largest in the animal kingdom), strangely imposing compared to its head, also allow it to see naturally in total darkness.
Moreover, the species is more or less protected from fishing and other anthropogenic environmental pressures, which could probably give it time to grow and then reproduce quietly, out of sight, to reach impressive sizes.