Globetrotting Giant Squid Are All One Species
What has eight arms with hundreds of suckers, eyes the size of grapefruit and a razor-sharp beak? A giant squid! A team of scientists and the Discovery Channel shot footage of this notoriously elusive creature in action. Click ahead for more squidly fun.
Giant squid have captured, and terrified, the seafaring imagination for centuries. This illustration recreates a giant squid observed off Tenerife in November of 1861.
This giant squid was collected by NOAA researchers off the Louisiana coast in the Gulf of Mexico. The largest invertebrate on Earth, the giant squid is just plain big -- the largest ever found was 59 feet (18 meters) long.
The only squid bigger than a giant is the colossal squid. Captain John Bennett examines the world's first intact adult male colossal squid in 2007 in the Ross Sea, near Antarctica. The squid was about 33 feet (10 meters) long. Check out those suckers!
These two female giant squid were found off Luarca, Spain. For an idea of the size of these creatures, note the gloved hand in the upper-left.
Alien autopsy? Nope. It's one of the Luarca squid from the previous slide, undergoing an examination by Spanish scientists.
Here's a giant squid measuring about 28 feet (9 meters), on display at London's Natural History Museum. This creature was caught in March of 2004, at a depth of 722 feet (220 meters), off the Falkland Islands in the South Atlantic.
A cat strolls past a giant squid in January 2005 in Newport Beach, Calif. That winter hundreds of 3- to 4-foot-long (0.9 to 1.2 meter) squid washed up along the Southern California coast. One theory holds that they ran ashore while chasing grunion.
This is another shot of a squid from the Newport Beach, Calif. wash-up. Giant squid eyes look so human because they’re structured much like human eyes are.
It may look big in the photo, but this larval squid is just 0.4 inches (1 centimeter) long and was photographed through a microscope by Russ Hopcroft, of the University of Alaska Fairbanks.
The humboldt, or jumbo, squid is a carnivorous marine invertebrate with a lifespan of only 1-2 years. But it makes hay while the sun shines on its short life: In that time, it can grow to 4 feet (1.2 meters) long.
We may know it better as calamari, the familiar appetizer, but its proper name is common market squid. This adult market squid was photographed off La Jolla Shores Beach in La Jolla, Calif.
This adult jumbo squid was caught near the Channel Islands by a squid jig aboard an NOAA research ship in 2007. Its tentacles are wrapped around the jig that was used to catch it, which worked by attracting the squid to its glowing yellow plastic.
This is a closer look at the 2007 Channel Islands squid. Its telltale large eyes allow the creature to see in the very low light that permeates its deep underwater habitat.
A squid's razor-sharp beak is a merciless weapon against its prey, allowing it to chomp tasty bites out of its victims. Here we see a close-up of a Caribbean reef squid's beak.
Giant squid, which can grow to an astounding 43 feet long, have equally extraordinary DNA, a new study concludes.
The long-awaited report, published in the Proceedings of the Royal Society B, finds that there is “exceptionally low” genetic diversity among giant squid from around the world.
“These observations are consistent with the hypotheses that there is only one global species of giant squid, Architeuthis dux,” wrote Inger Winkelmann and colleagues, who suggested that the squid could have one of the largest known ranges of any species.
Little is known about giant squid, which can live some 3,300 feet below the surface. Mostly we know about them from fantasy adventure books, like “20,000 Leagues Under the Sea,” and images of them dead, with their long tentacles dangling far beyond the picture frame. Giant squid are rarely captured alive, with most found stranded on beaches or seen floating dead on the water’s surface. Unfortunately, some are also retrieved by fisheries as by-catch .
Winkelmann, from the University of Copenhagen’s Natural History Museum of Denmark, and colleagues studied the mitochondrial genome of tissue samples from 43 such giant squid. “Mitochondrial” refers to a type of DNA inherited only through the female line. The squid came from all over the world, including waters off of California, Florida, Spain, Japan and New Zealand.
Incredibly, all had the same basic mitochondrial genomes. If there is just one giant squid species, as the researchers suspect, then adults must travel huge distances. Younger squid might disperse via drifting.
Giant squid might also be more plentiful than previously thought. But the lack of genetic diversity could make this species more vulnerable to human impact. Back in the day, fishermen rarely encountered the deep-dwelling squid. Now, with modern trawling equipment and huge fishing operations, the squid are more likely to become by-catch.
Pollution and climate change could also hurt the squid, as could loss of their food sources. They are thought to primarily feed on deep sea fish and other, smaller types of squid.
Marine biologists dissecting giant squid, Long Marine Lab, Monterey Bay, California