The 1-meter-long shark has a total olfactory membrane area of 4,842 square centimeters, so the shark’s sense of smell is very sensitive. It smells bloody a few kilometers away. Once the animals in the sea are injured, they are often killed by sharks. Shark‘s vision, smell, taste and touch Because the shark’s eyes are on either side of the head, it can almost feel the light in all directions. Because of the special structure in the shark’s eye, sharks can feel the light in the water, day or night.
The nostrils of the shark are divided into two parts, the front part is the water inlet hole and the rear part is the water outlet hole. The shark’s sense of smell is very sharp, it can distinguish the taste of one billion in the water. There are many small taste cells in the shark’s mouth. They are very sensitive to food stimulation. The shark uses taste to judge whether the food being caught is delicious. Like some rotten food sharks will not be interested. The shark’s touch is mainly felt by the nerve endings under the skin’s surface.
Any object that swims around the shark will feel it. The researchers found that when comparing the smells of the two nostrils, the sharks used the “stereo-smell” on their noses to detect the tiny intervals between the two nostrils smelling – half a second. The researchers also found that when the sharks detected this time interval, they turned to the direction of smell for the first time. The study, published in the journal Contemporary Biology, helps solve the puzzling shark problem. Scientists at the University of South Florida tested eight smooth sharks and a small taupe shark in the laboratory. The first author of the study, Jenny Getty, connected two tubes to the head of the shark in a sink containing 50 litres of seawater, and then circulated the smell of the marinated trout to each nostril of the shark.
She found that sharks rely on various directional cues based on smell and water to orient themselves and find what they are looking for. If the odor reaches between one nostril and the other nostril between one-tenth and one-half of a second, the shark turns its head to the side where they first smell the squid.