Colossal squid

The colossal squid lives in the deep, cold Southern Ocean around Antarctica. It is thought to be the largest squid in terms of weight. A confirmed specimen weighed at least 495 kilograms, and some animals known only from beaks in sperm whale stomachs may have reached 600 to 700 kilograms, which would make it the heaviest known invertebrate.

It is sometimes called the giant squid, but it is a different animal from the true giant squid. Its body is up to about 4.2 metres long, and its arms and tentacles are armed with hooks, some of which swivel. Its eyes are the largest of any known animal, an estimated 27 to 30 centimetres across. It is listed as Least Concern.

An ambush predator of the deep

Scientists believe the colossal squid lies in wait for fish rather than chasing them. In life its two long tentacles are hidden, and they shoot out only to grab prey. It is the only squid of its family, the glass squids, with hooks on its arms and tentacles. Very few full animals have ever been seen, so much of what we know comes from dead specimens and from beaks.

Food for sperm whales

The colossal squid is a main food of the sperm whale, which dives deep to catch it. The huge eyes are thought to help it see in the dim light of the deep sea. Measurements of 10 to 14 metres including the tentacles exist, but they come from stretched dead animals, so the body length of about 4.2 metres is the safer number. Because it lives so deep and so far south, very few people have ever seen one alive.

On the globe

The model floats in the cold waters of the Southern Ocean. Look for the huge eyes and the hooked arms.