But these are just fantastic stories, and giant squid probably never sank ships, according to Dr. Clyde Roper, a scientist at the Smithsonian Institution's National Museum of Natural History in Washington, D.C. He is a leader in giant squid research.
The giant squid, Architeuthis (ark-ee-TOO-this), is one of the biggest animals in the ocean. Giant squid look much like the smaller squid served in restaurants. They have eight arms (which many people incorrectly call tentacles) and two longer arms (properly called tentacles) for catching their prey.
But most giant squid are thirty to forty feet long, and some may grow to sixty feet. They can have eyes nearly as big as volleyballs and tentacles as long as a school bus. "Being so big helps protect giant squid from most predators in the deep sea," Dr. Roper says.
Giant squid live so deep in the oceans that no one has even seen one in its natural habitat. Scientists get much of their information by examining dead specimens. Throughout the world, only about one hundred dead or dying giant squid have been found. Since most of them are badly damaged, one squid may give just a few clues. Scientists put the clues together like the pieces of a puzzle.
They think the giant squid's huge eyes might help it find its favorite foods-smaller squid and fish-in the darkness of the deep. When the giant hunter gets close to its prey its tentacles shoot out and snatch the victim, gripping it with large suckers ringed with sharp barbs called teeth. The tentacles draw the prey into the mouth, with help from the eight arms. Inside, a hard beak like a parrot's cuts up the food.
Roper hopes to answer many questions about giant squid. How do they swim? How do they mate and have young? For many other animals, marine biologists have the answers to such basic questions- but not for giant squid.
When a giant squid washes ashore, Roper hurries to the site. He takes many photographs and measures the length and width of the squid's body the length of the tentacles and arms, and the width of the eyes. He will add the information to his collection of clues.
One clue was discovered at a party when Roper and two other scientists cooked a piece of giant squid. They expected a giant delicacy But it was awful. The taste reminded them of ammonia, a strong-smelling substance. They tested the tissue and found a lot of ammonia. They think that ammonia makes the giant squid less dense than seawater, so it won't sink. It can easily stay at a good level for finding food without constantly swimming and wasting its energy
The sperm whale, largest of the toothed whales, is the giant squid's main predator. Sperm whales and giant squid have been seen at the surface of the ocean, locked in fierce battles.
Whales that die and wash ashore sometimes have giant squid in their stomachs, Cutting into the stomach of a dead whale is messy and smelly but gives more clues.
This kind of detective work has helped. The skin of squids is pigmented, or colored, on the outside. Roper has learned tha the giant squid's body is pigmented on the inside, too. This makes its skin very dark.
Roper has thought about the meaning of this clue. Many deepwater fish have organs that make them glow. Giant squid probably eat a lot of these glowing fish. Even in a giant squid's stomach, just-caught fish could continue to glow. Roper thinks this darker skin hides the glowing stomach so that big predators won't be attracted.
Many questions about the giant squid are still unanswered. Biologists need to get closer to the living animal in its habitat. They would like to use tiny submarines called submersibles, which can take them into the deep sea. But the submersible's bright lights and noisy engine could warn off a giant squid.
To get close, a submersible would have to behave like a whale, says Roper. It would need to move silently and have the kind of sonar that sperm whales use to hunt prey. "The best way to track down a giant squid," says Roper, laughing, "would be to use a well- trained sperm whale that could catch one."
The National Museum of Natural History recently opened a new exhibit featuring the giant squid.
Ocean Planet Exhibition Floorplan
Smithsonian Giant Squid Overview Page
gene carl feldman / firstname.lastname@example.org