Sailfish hunting techniques
left billed or right billed?
Are you left handed or right handed Mr. fish? A question that seems to be a little unreasonable to ask – because, of course, fish don’t have hands. But besides this little anatomical hiccup they do seem to prioritise one side when it comes to body movements. Individuals of many fish species have been shown to favour one or other side, a recent example, the Indo-Pacific sailfish (Istiophorus platypterus) show this lateralisation specifically when they are hunting. Sailfish are top predators and hunt small pelagic fish like sardines (Sardinella aurita). Even though sailfish can swim fast, their smaller prey can manoeuvre more nimbly, so pure speed does not make a successful hunt.

Sailfish have another feature to help in their hunt: long bills that they use like a sword to slash their prey. These bills are long and thin and can be moved through the water column much faster than their massive body can. But like any skilled swordsman has a preferred arm or stance, sailfish tend to use a particular side when they attack. This makes the movement more precise and even faster. But as we would most likely duck to the left when we anticipate a sword attack by a right handed swordsman, should sardines not also see the attack coming? Not if they are confronted with predators that show different lateralisations! And this seems to be the case: every sailfish specialises in a different side and left-sided seems to be as common as right-sided! When hunting together sailfish take turns to attack a school of prey fish which keeps the prey guessing as to which side the attack will come from, and improves the hunting efficiency of the sailfish.

If you are keen on seeing these amazing creatures hunting check out this Video

Author and Illustrator: A. Loth