VANCOUVER - They're the stuff of myth and B-grade horror movies, giant tentacled sea monsters roaming the deep in search of prey.
Giant squid have tuned up on East Coast shores for hundreds of years, and now new research is shining some light on the B.C. sea monsters.
An international team headed by Danish researchers tested DNA samples from 43 giant squid from around the world — including a specimen from Newfoundland — and were stunned to find that there is likely just a single species of the massive cephalopod.
The genetic diversity among the samples was lower than almost any species ever reported, said Tom Gilbert, a researcher from the Natural History Museum of Denmark at the University of Copenhagen.
"That lack of diversity and no population structure is just crazy. We just cannot explain it easily once you start thinking that this is an animal that lives everywhere," Gilbert said in an email interview.
"We wanted to find answers. We ended up making more questions."
The study, published Wednesday in the Proceedings of the Royal Society B, left researchers with several theories, including that the creatures may have come close to extinction and then rebounded.
Giant squid, or Architeuthis, are one of the largest invertebrates on Earth. They are found in oceans from New Zealand to Ireland, and can reach a maximum of 18 metres in length, according to the article.
Until recently, the creatures were so rare that they remained largely lore, including the sea monster hungry for human flesh in Jules Verne's 1870 novel "20,000 Leagues Under the Sea."
"Because of their huge size and elusive nature, many myths and legendary sea monsters have been based on them, including the fabled sinker of ships, the Kraken," says the article.
One of the earliest recorded sightings was in 1785 off the Grand Banks of Newfoundland — the first of many off the Atlantic coast of Canada. There were unconfirmed reports of giant squid off the B.C. coast four years ago, but repeated requests for information and interviews with Fisheries and Oceans Canada researchers were not successful.
Until 2006, when researchers managed to hook a live giant squid using bait near the Ogasawara Islands, south of Japan, the only known specimens had washed up dead on beaches.
In January, Japanese scientists made headlines around the world when they captured video images of a giant squid in its natural habitat for the first time. The video, filmed from a manned submersible in the Pacific Ocean last summer and aired on the Discovery Channel this year, showed the three-metre cephalopod about 900 metres below the surface.
The researchers have several theories, including that the population may have shrunk to near-extinction and then expanded. Why? They suspect that a decline in predator populations, such as the near-extinction of whales in the 19th century, may explain it but could be too recent.
Cephalopods in general are very sensitive to climatic effects, said the article, and they have shown to increase dramatically when food competitors have been depleted by heavy overfishing.
But it's all a guess at this point, Gilbert suggested, as research has yet to reveal key aspects of the giant squid's life cycle.
"Our estimates are rubbish, to be honest. We really have no idea how accurate our mutation rate is ... , as we can't measure key things like giant squid generation time," he said.
Gilbert said the study does help humankind understand this creature and this world a little better.
"I suspect this will get a lot of press as its so iconic and that will, we hope, inspire many of today's youth to want to be scientists, or better conserve the environment … and that can't be a bad thing."
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