All Giant Squid Members Of Same Species, DNA Study

The giant squid genus just lost up to seven species — but not to extinction. A new DNA analysis has proved that all giant squid, previously thought to belong to as many as eight species, is really all one species, Architeuthis dux. That’s the report from a team headed by the University of Copenhagen’s Inger Winkelmann and colleagues, which was recently published in the journal Proceedings of the Royal Society B.

The team studied the mitochondrial DNA (found only in the female line) to determine that there was an exceptionally low level of genetic diversity within the species. They took the DNA from 43 specimens from wide distances apart around the ocean including offshore Japan, New Zealand, Spain, California, and Florida. All had essentially the same mitochondrial genomes, making them too closely related to be members of different species.

A deep ocean-dweller, the giant squid was more myth than reality for most of human history. It was not photographed alive until the 21st century, although glimpses had been seen from ships for centuries. And, of course, some giant squid were washed up dead on beaches over the years, including a 20 footer found in Newfoundland in 1878.

While there were some earlier attempts made at videotaping giant squids, Japanese public broadcaster NHK and the Discovery Channel made a splash earlier this year when they released the documentary Monster Squid: The Giant Is Real, which they promoted as the first genuine footage of a giant squid in its natural ocean habitat. It featured a 26 foot long squid.

If one species of giant squid just isn’t enough, you’ll be relieved to learn of the existence of an even bigger one. The colossal squid, Mesonychoteuthis hamilton, is also the only member of its genus. Possibly even larger and certainly heavier than the giant squid, its arms have hooks as well as suckers.

The Discovery Channel noted that the colossal squid still has never been seen by human eyes in its natural habitat, although a 1,000 pound specimen was caught by fishermen offshore New Zealand in 2007.

And it may sound like a fish story, but Discovery also said that giant squids fight with sperm whales, damaging their enemies enough to leave sucker and bite marks.

I don’t know about you, but I think I smell a sequel. Something tells me that we haven’t heard the last of the giant squids.

[giant squid photos: Per Gätzschmann, NTNU Museum of Natural history and Archaology]