Doctor Dre

Sharks Have More Sense(s)

At one time, scientists assumed that the shark?s nose was the main weapon in their arsenal, for ferreting out prey. After all, a shark can sniff out blood in concentrations as low as one part per billion, from a mile away. To prove their point, they plugged the noses of sharks, and found them confused, and unable to locate prey that was purposely placed there for the taking.

What wasn?t taken into account with those first studies, was what other senses the sharks had, and how the combined use of them make the shark one of the most feared predators in the ocean, and for good reason.

Yes, the sense of smell is very sharp. It?s also a directional resource, with a nostril on each side of the shark?s nose, which can then take in the scents coming from two different locations.

But their hearing is also acute, and most likely to pick up low frequency sounds with a pulse, such as the signals given off by injured or dying fish. These sounds are below the range of human hearing, and when seeking prey, a shark may follow them for some distance to determine whether the source is food.

They are also gifted with something called the ampullae of Lorenzini, which enables the shark to sense low level electrical impulses given out by living creatures. The ampullae are clusters of electrically sensitive cells located under the skin on their heads. Those cells are connected by jelly-filled tubes to the pores, and thus to the outside world, from which they can receive the signals of hidden prey.

All of these talents make an almost unbeatable combination, giving the shark multiple options for seeking out and tracking down their next meal. They also help to make up for the fact that sharks are somewhat far-sighted, and can?t locate food that is right under their nose, unless they are able to call on one of their other resources.

__________________