Recent Studies Cast Doubt on Myths About Mysterious, Seldom-Seen Squid World’s Largest Invertebrate May Not Reach 3,000 Feet After AllBy Henry Fountain
the new york times -- With a length up to 75 feet, the giant squid, Architeuthis, is the largest invertebrate on earth. But it is also the most elusive. It has never been seen alive in its natural habitat.
As such, Architeuthis (pronounced ark-uh-TOOTH-us) has something of a mythical reputation. There has been speculation that the creatures live for decades, even a century, at depths of several thousand feet.
“No one really knows,” said Dr. Neil H. Landman of the American Museum of Natural History. “In the ocean there are still mysteries, and this is one of them.”
But research by Landman and colleagues from the State University of New York at Stony Brook and other institutions may help dispel some of the myths. Architeuthis, they say, may not be so long in the tooth, and reports of its depth may be greatly exaggerated.
The researchers studied one of the squid’s smallest features, a bonelike particle called a statolith that is not much larger than a grain of sand. Statoliths, which are found in the squid’s head and help it maintain equilibrium, grow through the buildup of calcium carbonate in discrete rings.
Landman analyzed isotopes of oxygen in statoliths from three southern giant squid, Architeuthis sanctipauli, from the Pacific Ocean. Like all specimens, these were caught in fishing nets or washed ashore. The proportion of isotopes gives an indication of the water temperature the squid lived in, and temperature can be related to depth.
In the analysis, reported in the journal Marine Biology, Landman found that the squid lived at depths of 600 to 1,000 feet. While he noted that those figures are not definitive, they are a far cry from 2,000 to 3,000 feet, as some scientists have thought.
The statoliths were also analyzed for carbon-14, a legacy of atmospheric weapons tests. Carbon-14 in the Pacific increased from the 1950s to about 1980, then began a well-documented decline. By analyzing carbon-14 ratios, the researchers were able to calculate an age for the squid: 14 years or less.
Normal squid reach full size in a matter of months (“They’re the broiler chickens of the sea,” Landman said), so some scientists had thought that giant squid might grow as fast.
Landman said he thought the giants add heft relatively rapidly, though not at the pace of their cousins. After all, he said, “It’s hard to imagine something growing that big so quickly.”