A monster suddenly ascends from the sea, snatches the boat, and drags the sailors down to a watery grave. This story line provides the plot for legends that have persisted through the ages. But do monsters that large really exist?GIANT SQUID
In 2007 a colossal squid was accidentally caught by fishermen in the Ross Sea off Antarctica. It was about 33 feet [10 m] long, including its tentacles, and it weighed over 1,000 pounds [nearly 500 kg]! Scientists believe that this species of squid can grow even larger.
A similar sea monster known as the giant squid has a torpedo-shaped body, eyes that can be as large as a human head, a parrotlike beak strong enough to cut a steel cable, eight arms with rows of suckers, and two long tentacles that bring food to its mouth. It can propel itself through the water at 20 miles [30 km] an hour and even launch itself into the air!
Fewer than 50 sightings of such giants have been reported in the last century, and these creatures have never been studied in the wild.
Colossal and giant squids, however, are just a meal for an even larger animal, the sperm whale, which can grow to about 60 feet [20 m] in length and weigh as much as 50 tons. One tooth alone weighs two pounds [900 g]! Dead sperm whales have been found with portions of giant squid in their stomach. These whales also had circular scars from squid suckers on their huge, blunt heads, showing that the squid put up a hard fight. In 1965 the crew of a Soviet whaleboat claimed to have seen a battle between a giant squid and a 40-ton sperm whale. Neither survived. The strangled whale was found afloat in the sea, with the head of the squid in its stomach.
With its 3,000 formidable teeth, the great white shark is perhaps the most frightening carnivorous fish. The largest great white on record was 23 feet [7 m] long and weighed 7,000 pounds [3,200 kg]. This shark has an extraordinary sense of smell, being able to detect one drop of blood diluted in 25 gallons [100 l] of water!
Another large sea creature is the giant octopus, which can weigh up to 600 pounds [250 kg]. Once called devilfish, it was thought to be able to sink ships. Yet, this octopus is actually shy and hides in rock dens and crevices on the seafloor. Its eight arms can have a span of 30 feet [10 m], and it possesses the largest brain of any invertebrate. Indeed, octopuses are highly intelligent and can learn complex tasks, such as solving mazes and unscrewing jar lids!
Like the giant squid, the giant octopus can camouflage itself by changing color, use jet propulsion to move through the water, and escape danger by squirting a dense cloud of ink. The octopus can even leave the water for a short time to search for food on land!