Shark's Sense of Smell Tested

In the latest issue of Current Biology, a team of American researchers from Florida and Massachusetts have tested the way that sharks sense of smell works in an innovative and amusing experiment. It is well known that sharks have a phenomenal sense of smell, being able to detect prey from great distances. It was previously assumed that sharks measure the the strongest smell, from the left or the right nostril, to align themselves with the source. The researchers investigated this by wiring up the nostrils of dogsharks to with tubes containing squid odour. The right nostril was given the smell of squid first, then half a second later the left nostril was given an even stronger smell of squid. It was found that the shark would swim in the direction of the first source of squid odour even though it was the weaker one. It is thought the reason for this is that ocean water currents can be very chaotic and it is more reliable to follow the direction of the smell that was first detected in order to get the food.