Sailfish Whips Sword-Like Bill At Scientist During Research Dive [VIDEO]
While swimming with sailfish to capture their breakneck movements on camera, one researcher ended up playing chicken with one of them.
Like Us on Facebook
In a video released this week in conjunction with new research, Alexander Wilson was using underwater cameras to film a pack (they're more like wolves than fish) of sailfish as they hunt a school of helpless sardines. In slow motion, the sailfish are seen ripping through clusters of prey, battering the sardines with their powerful beak-like mouths, called bills. Around a minute in, a sailfish appears literally out of the blue, and it's speeding straight for Wilson.
"In this case, one of the sailfish mistook my GoPro for a sardine (I am assuming since it is small and silver) and took a brief dash towards it," Wilson, a biologist at Carleton University, in Canada, told me in an email. Sailfish can swim as fast as cars on an expressway, upwards of 65 mph, and they can turn on a dime. That's what this one ultimately did, at the very last minute.
"While it can be quite startling when this happens (hence my 'flinch'), the sailfish are actually amazingly adept at avoiding situations which might result in damage to their bill," Wilson says. "So while this can be very exciting, it's not quite as dangerous as it looks!"
Wilson and his colleagues published a study Thursday in Proceedings of the Royal Society B called "How Sailfish Use Their Bills To Capture Schooling Prey." They describe, for the first time using slow motion footage, the methodical process that sailfish use to hunt their supper. "Our results demonstrate that the combination of stealth and rapid motion make the sailfish bill an extremely effective feeding adaptation for capturing schooling prey," the authors wrote.
Summarized on the website of the journal Nature, Wilson's team discovered, during six days of filming in the Atlantic in 2012, that sailfish basically don't ever get tired. They work together to slowly infiltrate a tight herd of sardines, then whip their sword-like bills with the acceleration of a major league baseball bat (all the more impressive under water). Nature describes it sublimely: "The result is a scene of fishy carnage, as the surrounding water fills with iridescent fragments of sardine skin."
On the other hand, they can also use their bills less violently. About half the time, they don't wield their bills like cop batons. Instead, they gently prod a single fish away from the school — then devour it, frightened and alone. Once a school of sardines is singled out by a group of sailfish, there can be no hope. Researchers actually call them a "baitball."
"When the baitball ... get very low (10-15 sardines), sailfish dart in from all directions to finish off all the stragglers ... in just a few seconds," Wilson says.
© 2012 iScience Times All rights reserved. Do not reproduce without permission.