The giant squid has been an enduring mythological creature among sailors for centuries. Many reports throughout history have documented encounters between these animals and boats, and several specimens were found beached on the shores of an assortment of nations. In addition to this evidence, Japanese researchers filmed a live one in its natural habitat in 2004, confirming, to the delight of many, that it is an actual living animal. Not only that, but another species of squid, the colossal squid, gets even bigger.
There are eight individual squid species in the genus Architeuthis, which is in the family Architeuthidae. It is believed that giant squid can reach lengths of up to 46 feet (about 14 meters), placing them among the largest animals on Earth. The huge animals are comparatively lightweight for their size, because the bulk of their length is taken up by trailing tentacles. The ocean-dwelling creatures are believed to have the largest eye of any animal on Earth, measuring 1 foot (about 30 centimeters) across in an adult specimen.
Colossal squid, known as Mesonychoteuthis hamiltoni, can get even larger. It has movable grappling hooks on its tentacles, rather than suckers like its slightly smaller cousin. The colossal squid also has a larger mantle, the protective casing that covers the body of the animal, making it stouter and heavier than the giant squid.
Both types of squid are very muscular and feed on a wide range of other animals in the ocean. Because of their formidable size and strength, they have very few natural predators. Both sperm whales and sleeper sharks appear to eat them, judging from evidence found in the digestive tract of both animals. The squid does not go down without a fight, however, and sperm whales with suction cup scars have been seen.
Because it is an elusive animal, documentation of the giant squid alive is very rare. The Japanese researchers who released video in 2004 took several years to accumulate their data, focusing on a region where sperm whales congregated in the hopes of catching a live squid on camera. Most of the specimens that have been studied have washed up on shore in various parts of the world, suggesting that the animal can be found in all the world's oceans. Some have also been caught by fishing boats and turned over to scientists for study.