Japanese researchers discover gliding squid that use jet propulsion
Researchers prove that molluscs become airborne with the help of jet propulsion
Agence France-Presse in Tokyo
Japanese scientists have confirmed the long-rumoured secret power of a species of oceanic squid. It can fly.
The unlikely aerialists were witnessed zooming across the ocean surface for more than 30 metres at speeds faster than champion sprinter Usain Bolt, the researchers said yesterday.
Researchers say is the first time anyone has described the mechanism the flying mollusc employs. The squid propel themselves out of the ocean by shooting out a jet of water at high pressure, before opening their fins to glide at up to 11.2 metres per second, Jun Yamamoto of Hokkaido University said.
Olympic Gold medallist Bolt averaged 10.31 metres a second when he bagged gold in London last year.
"There were always witnesses and rumours of squid seen flying, and we have proved that it really is true," Yamamoto said.
Yamamoto and his team were tracking a shoal of around 100 of the squid, dubbed the neon flying squid, in the northwest Pacific 600 kilometres east of Tokyo, in July 2011.
As their boat approached, the 20cm creatures launched themselves into the air with a powerful jet of water that shot out from their funnel-like bodies.
"Once they finish shooting out the water, they glide by spreading out their fins and arms," Yamamoto's team said in a report.
"The fins and the web between the arms create aerodynamic lift and keep the squid stable on its flight arc. As they land back in the water, the fins are all folded back into place to minimise the impact."
A picture taken by researchers shows more than 20 of the creatures in full flight above the water, droplets of water from their propulsion jet clearly visible.
"We discovered that squid don't just jump out of water but have a highly developed flying posture," the report said.
The squid are in the air for about three seconds and travel upwards of 30 metres, said Yamamoto, in what he believed was a defence mechanism to escape being eaten.
But, he added, being out of the ocean presented new risks, leaving the cephalopods vulnerable to other predators.
"This finding means that we should no longer consider squid as things that live only in the water. It is highly possible that they are also a source of food for sea birds."
The study was published by German science magazine Marine Biology this week.
News of the finding comes after other Japanese scientists last month unveiled the world's first pictures of the elusive giant squid in its natural habitat, more than half a kilometre deep in the Pacific ocean.