In 2010 from the deck of a cruise ship along the coast of Brazil, amateur photographer and retired geologist Bob Hulse snapped some high-resolution photographs of something unusual leaping from the sea: what appears to be dozens of squid propelling themselves through the air and at incredible speeds. Quite possibly the first time the impressive display had ever been caught on film. Researchers had suspected for sometime that squid can sometimes leave the water's surface. A 2004 study by University of Miami researchers collect six such sightings, but because the paper included no photographs or video clips its evidence was largely anecdotal. Documented instances of flying squid remained frustratingly rare. The Hulse photographs changed all that. Ronald O'Dor, a marine biologist at Dalhousie University in Halifax, Canada, has analysed the images. Because Hulse documented the intervals of time between each photo, O'Dor and his colleagues were able to estimate the squid's velocity and acceleration, and compare them with these values for squid in water. They found that the velocity in air while the orange-back squid (Sthenoteuthis pteropus) were propelling themselves via water jet was five times faster than than any measurements for comparable squid species in water.
Further evidence came from Julia Stewart, a marine biologist at Hopkins Marine Station of Stanford University in Pacific Grove, California, who uses tagging to track the movement of Humboldt squid (Dosidicus gigas). Her work found that they travelled faster than anyone expected. "The question this raised in my mind was, 'Maybe they really are flying?'"
Not only can squid sometimes fly, but they do so to save energy while travelling long distances. Stewart and O'Dor presented their findings during this week's American Geophysical Union's Ocean Sciences Meeting in Salt Lake City, Utah.
↧