The vision of a hammerhead shark

29januari2010
Source: nationalgeographic.com
The head shape of hammerheads has always amazed people, but until now it hasn’t been researched very much. Florida Atlantic University changed this. Researchers from this university studied three (out of nine) species ...
of hammerheads, particularly their vision. The sharks were caught in the wild, investigated in the lab and then released back into the wild. Weak lights were shone at the sharks from the front, the side and from above, while electrodes measured the sharks’ brain activity.
It appeared that the overlap between what they can see with their left and right eyes is three times higher than in other species with a pointy shaped head. This overlapping area allows them to see depth and is called stereovision.
It is now assumed that the head of the hammerhead shark has its particular shape to allow the animal to see depths better and therefore be better able to hunt fast prey. Squids move around very quickly in three dimensions and are therefore very challenging prey. The shape of the hammerhead’s head does not only have benefits though. The disadvantage of it is the larger blind spot directly in front.