Flying squids: the rocket science behind cephalopods

From Los Angeles Times: Flying squids: the rocket science behind cephalopods
Squids can fly? If you are a member of the relatively small community of squid aficionados you've known this for a while.

But if you are a normal person with just a passing interest in cephalopods and all their many diverse abilities, the fact that these underwater creatures also occasionally get from point A to point B by flying above the water for distances of up to 164 feet at a time might just blow your mind.

Ron O'Dor, a marine biologist at Dalhousie University in Halifax, Canada, and co-author of a poster called "Squid Rocket Science" presented at the American Geophysical Union’s Ocean Sciences Meeting in Salt Lake City, said squids have good reason to fly. It is not to avoid predators, as was previously thought, but rather to save the animal energy as it migrates across vast expanses of ocean, O'Dor said.

"The acceleration rate in air is five times faster than any acceleration I've measured in a squid in water," he said. "And once they are gliding in the air, they aren't expending any resources."

Squids are able to propel themselves out of the water in the same way they swim through the water — by filling their mantle up with water and then forcing it out at very high velocities and pressures. Once a squid has propelled itself above the water, it can contort itself into a rocket — its fins catching the air like wings, the tentacles curled up to create another flat surface in the rear. How far the squid can go at that point is limited only by the wind.

If squids are such proficient fliers however, why isn't squid flight something more people know about?

O'Dor thinks the reason is that squids are more likely to fly at night, when it would be harder for predators such as birds, as well as human observers, to catch them in the act.

He came to this hypothesis after observing some squids that he kept in a 15-meter pool at Dalhousie University. Each morning, when the research team checked on the squids, they would find a few dead squids around the outside of the pool. O'Dor found that by not completely turning off the lights at night, and only dimming them, the squids were less likely to jump out of the pool.

Conclusion: Squids only like to fly in the dark.

Reports of squids gliding above the waves go back to the 1890s.

In 1947 Thor Heyerdahl noted that squids would occasionally fall from the air onto his raft as he attempted to sail from Peru to the Polynesian islands in an effort to prove that people from South America could have settled in the South Pacific islands.

But photographic evidence was hard to find. In 1970 National Geographic obtained an 8 mm video of a large flying squid 6.5 feet long. And then, in 2010, a man named Bob Hulse shot a bunch of photos of squids rocketing above the ocean, off the coast of Brazil.

O'Dor, who hopes to publish a paper about squid flight soon, says there is still much more research to be done to understand the ins and outs of rocketing squids.

He is trying to get funding to tag species of squid that he suspects of flying, to see how much they fly and at what times.