Sharks possess an impressive array of senses that they use to navigate through the underwater world and to find prey. They have all the same five senses that people have, plus two more. Sharks' sense of smell is legendary.
In addition to those we have – sight, hearing, touch, smell and taste – sharks have two other senses, mediated by specialized receptors: electroreceptors and lateral lines. A shark's most acute sense, the one it may use to detect prey from the greatest distance, is probably its sense of hearing.
The senses that protect the individual from external and internal perturbations through a contact delivery of information to the brain include the five senses, the proprioception, and the seventh sense—immune input. The peripheral immune cells detect microorganisms and deliver the information to the brain.
SMELL. Up to two thirds of the total weight of a shark's brain is dedicated to smell. They're super-sensitive to smells that are important to their survival. Including scents produced by potential predators, prey or a mate.
Sharks have the same senses as humans, smell, sight, taste, hearing and touch. They have also developed extra sensory organs that are specific to their underwater environment. Smell (olfactory) –Shark have highly developed olfactory senses.
A Shark's Sixth Sense
around their head called ampullae of Lorenzini. These are jelly filled pores that go down to the nerve receptors at the base of the dermis. They are specialized electroreceptor organs that allow the shark to sense electromagnetic fields and temperature changes in the water column.
But sharks don't have the capacity to smell fear. That doesn't mean that a shark isn't impressive with its ability to detect prey from vast distances using its sense of smell, however. Fear is a complex emotion and a shark's olfactory system isn't sufficiently equipped to detect it.
Sharks do sometimes look as if they're smiling. They're often portrayed in books and movies as smiling. But scientists say it's not likely sharks can or do smile.
Not if you plan on getting away. Despite the old saying that aiming for the snout is the best strategy, a shark's most sensitive areas are really its eyes and its gills. Aiming for the nose, which is not known to be a weak spot, is generally considered a bad idea.
Sharks can detect a small drop of blood in the water from a distance of up to a quarter of a mile away. This is because sharks have an incredible sense of smell, which is up to 10,000 times more powerful than that of humans.
Easily identified and eminently useful is No. 13, the sense of equilibrium. Its most important receptors are three fluid-filled canals set in different dimensions in the labyrinth of the ear. This affords, says Foerster, "the ability to maintain balance even though our ears be plugged and our eyes closed . . .
Because there is some overlap between different senses, different methods of neurological classification can yield as many as 21 senses. And this number does not include some physiological experiences such as, for instance, the sensation of hunger or thirst.
Interoception is the sensory system that helps us assess internal feelings. And increasingly, it's being recognized as the 8th sense along with sight, sound, smell, taste, touch, balance and movement in space (vestibular sense) and body position and sensations in the muscles and joints (proprioceptive sense) .
Some sharks such as the nurse shark have spiracles that force water across their gills allowing for stationary rest. Sharks do not sleep like humans do, but instead have active and restful periods.
So, do sharks feel pain? Yes – but it is different to how we express pain . Sharks do not have the same nervous system as mammals but what we do have in common are neurons called nociceptors. These receptors are designed to detect potential harm – such as temperature and pressure.
Hammerhead sharks can effectively see above, below, in front and behind – 360-degree sight. One last thing – shark pupils can dilate. When they are in low-light conditions, the pupils are large circles, letting as much light in as possible.
Sharks and dolphins are two of the most formidable creatures in the ocean, but while sharks are often seen as fearsome predators, they are known to be intimidated by dolphins.
Killer whale
Orcas are the real apex predators of the ocean. Killer whales may be the only animals on our list that actually prey on great white sharks. Otherwise known as orcas, these intelligent mammals belong to the dolphin family and are probably the top predators in the entire ocean.
Made of very strong and thick bone, dolphin snouts are biological battering rams. Dolphins will position themselves several yards under a shark and burst upwards jabbing their snout into the soft underbelly of the shark causing serious internal injuries. More than Peas in a Pod.
There is no scientific way to measure the IQ of sharks. However, scientists have observed that sharks are intelligent creatures that can learn from experience and adapt to changing environments. Sharks have complex social behaviors and are capable of problem-solving and decision-making.
Scientists have discovered a "shark graveyard" deep on the sea floor of the remote Western Australian coast containing hundreds of fossilised teeth, including those of a close relative of a fearsome prehistoric predator — the megalodon shark.
A New Shark Species Found In Australia
The Apristurus “demon catsharks” are small sharks that dwell deep underwater, where they feed on small fish and crustaceans and pose no threat humans, despite their name. Human thought the eggs might belong to the genus' species A.
Sharks are simply not attuned to sniffing out human blood because humans are not part of their diet. Most sharks eat other fish so that is what their senses are designed to recognize. In addition, the amount of blood that could be released into the water by a woman swimming while menstruating is very small.
FACT: Sharks know the difference between fish and human blood and, while they can smell our blood, it is not a scent they associate with food. Scientific experiments have repeatedly shown that sharks have no interest in human blood.
It has traditionally been believed that sharks are repelled by the smell of a dead shark; however, modern research has had mixed results. The Pardachirus marmoratus fish (finless sole, Red Sea Moses sole) repels sharks through its secretions.