Estimates for their maximum size reach 13m from tip-to-tip, although there are claims that they can grow much larger. Giant squid are only outmatched in size and weight by the colossal squid which are limited to the ocean around Antarctica.
The tentacles of the giant squid account for the majority of its length, with two longer feeding tentacles stretching beyond the other eight arms. Each feeding tentacle is lined by suction cups which are lined by serrated, chitin teeth. Circular scars can be found on the skin of sperm whales who hunt giant squid, evidence of incredible battles down in the deep. The tentacles encircle the giant squid's sharp, parrot-like beak which lies at the base of the squid's mantle (the main body), perfectly positioned for capturing then devouring prey.
Giant squid have one of the largest eyes of any creature to have ever lived, with the only living rival being that of the little known colossal squid.
At almost 30 cm in diameter, with a third of that being pupil, the giant squid has an eye perfect for detecting any light in the murky depths of the ocean. As the sun cannot penetrate to the depths that the giant squid inhabits, most of the light will be relatively weak bioluminescent light - identifying prey, potential mates or predators like sperm whales.
Japanese researchers from the National Museum of Nature and Science in Tokyo and the Ogasawara Whale Watching Association managed to successfully capture the first images of a living giant squid in September 2004. The same team then followed this up in December 2006 by being the first to get a living giant squid on film.
In July 2012, a team made up of NHK and the Discovery Channel filmed a live adult in the wild. Securing the footage was a sensational feat which gripped naturalists around the world. This trumped the earlier 2006 footage which featured an adult which was caught on a line being hauled onto a ship - the 2006 specimen wasn't swimming freely as the 2012 specimen was.
- Females are larger than males, reaching 13m and 10m respectively.
- Ammonium chloride, which is lighter than seawater, helps the giant squid maintain neutral buoyancy.
- You can tell the age of a giant squid by the growth rings in their statocysts, which are orientation organs.
- Although huge, the largest giant squid weight only a little more than the largest male lion.