This image shows something astonishingly cool: A group of about 50 sailfish collaborating to round up a massive ball of sardines. Both schools move in tandem as if they represent two collective minds.
This photograph was taken by diver/photographer Paul Nicklen for National Geographic. In a related video, he recounts exactly how the 8-foot-long sailfish work together to drive this roving ball of fish to the slaughter, injuring them with their sword noses, until they are exhausted and the gang of sailfish can move in for the feast. Of the photo above, he says:
More than a hundred sailfish keep tabs on an elephant-size school of sardines off Mexico's Isla Mujeres. The big fish, which can stretch eight feet tip to tip, drive their prey up from deeper water for easier feeding near the sunlit surface.