Hints that squid can propel themselves through the air have tantalized scientists for some time. When marine biologist Ronald O’Dor kept Northern shortfin squid in his lab, he’d sometimes be greeted with dead squid lying on the floor around their pool. When Julie Stewart tracked Humboldt squid, she found that they were somehow getting places much faster than anyone thought. And when retired geologist Bob Hulse was vacationing on a cruise off the coast of Brazil, he actually caught it on camera: little 2½-inch orange-back squid soaring through the air.
So the scientists put two and two and two together: O’Dor and Stewart recently presented their flying squid research based on Hulse’s photographs at the 2012 Ocean Science Meeting. Since the photographs were taken in burst mode, the researchers knew the exact time interval between each photograph. This let them calculate just how fast the squid were flying: five times faster than any measurements taken for squid in water. To propel itself out of the water and into the air, the squid fills its mantle with water and then quickly shoots it out. This is the same thing it does underwater, but air is less dense, so it produces more scoot for the squirt. O’Dor thinks that flight lets migrating squid save energy on journeys as long as 1,000 miles.
The researchers also hint that the squid may be using its fins to control its flight—so that it is more actively flying than, for instance, the so-called flying fish. More research is necessarily before drawing any conclusions about the aerodynamics and energetics of squid flight (if we can call it that).
A 2004 paper that collected anecdotes about flying squid considers an even more impressive hypothesis: “some squid might develop a temporary sheet of mucus between their arms that can provide lift while in flight.” Well, we’ll wait for the photographs.
[via Nature News]
Image courtesy of Wikimedia Commons / NOAA