Sharks - formidable predator of the seas and oceans
Probably because of all the predators living in the world, sharks are the greatest cause of human fear. It's hard to find a better and, at the same time, an older body. Sharks - a common and ancient predators has appeared 420-450 million years ago, and since then they have not changed much: in the form as we know them now, they were formed during the Jurassic period, when dinosaurs walked the planet more, and the first birds only just rose into the air.
With one of these predators has recently faced in Primorye. August 17, 2011 by 25-year-old boy was attacked by a great white shark and bitten off both his arms, and a day later injured 16-year-old diver, who escaped with the strongest leg lacerations.
In the waters of the oceans, there are about 350 different species of sharks, and each of them is unique. Today we take a closer look with some sharks, and find out which one of them is part of the "big three" most dangerous sharks for the man-killers.
Sharks - this aquatic animals belonging to the superclass of fish. All sharks -.. Predators, ie they use to feed animal feed - from the smallest plankton animals to large inhabitants of marine waters.
Sharks are very tenacious and do not have the sensitivity to pain, like other vertebrate animals. Their structure was so well honed evolution, sharks have survived in the long struggle for existence with different, often very powerful predators, while doing little to change in the structure of organs and body.
Do not forget that all sharks - predators. If you disturb these huge fish while hunting, consciously or unconsciously provoke them, even the safest types are quite capable of attacking humans.
By the way, what to do if you suddenly attacked by a shark? Small infographics on the subject of the RIA "Novosti":
blacktip reef shark
This species is common in the tropical Indian and Pacific Oceans. This is one of the most common sharks coral reefs, the reefs inhabit various types, living at depths of several meters. These sharks - small members of the family, they are not greater than 2 meters in length and weighs 45 kg. There are at depths of 30 cm or less.
Because of its small size it is, basically, is not dangerous to humans. Although there are cases of attacks on swimmers from the blacktip reef sharks. In all mentioned cases, aggression on the part of the shark was triggered by the smell of blood, flows into the water from a man harpooned fish.
blacktip reef shark - a sissy. For example, once during transportation due to human error in the tank water was two degrees below the minimum possible, and sharks have died from hypothermia. In another case, 35-year-old British comedian Guy Veneybls, who took part in the show in a nightclub in Brighton, jumped into the shark aquarium. The result of this sad antics turned 12-year-old shark died of fright.
nurse sharks, nurse
This shark can reach 4 meters in length, but typically does not exceed 2.5-3 meters. Something like catfish:
Hold at depths of 0, 5 to 3 meters, can gather in flocks of up to 40 individuals.
slow and less active, nurse sharks feed on crab, octopus, sea urchins, small fish.
As a rule, nurse sharks are safe for humans.
The sand tiger shark
This achieves predatoress typically 3.5-4 meter length.
Despite the rather frightening appearance, sand tiger has a rather peaceful character and attack humans only in self-defense. (Photo by David Doubilet):
It should be noted the original method of buoyancy used in this kind of sharks - air swallowing and arrest him in the stomach.
The sand tiger sharks are common, mainly in warm climates, especially a lot of them at the Australian coast. The biggest population lives off the coast of North Carolina, in sunken ships.
Teeth sand tiger:
At present, carcharias, like many shark species are threatened with extinction. All this led to the inclusion of sand tiger sharks in the list of protected fish and entering them in the International Red Book.
Divers to display the size of the sharks keep the 3-meter line:
Hammers - a large shark. This is the most unusual shark. The main distinguishing feature of the family is the hammerhead form of their heads - it is quite unusual shape - in the form of a hammer, T-shaped, the edges of which are the eyes.
According to one theory, the shape of a hammer head shark acquired gradually over millions of years, each generation has expanded at a tiny distance. According to another theory, a hammer came not as a result of gradual changes, and was the result of a sudden happened bizarre mutations.
They live these sharks in the warm and temperate waters of the Pacific, Indian and Atlantic oceans at depths of 300-400 meters. These aggressive hunters feed on various species of fish, octopus, squid and crustaceans.
hammerheads (except giant hammer) having up to 3.5-4.2 meters with a weight of about 450 kg.
In search of hammerhead shark food help, mostly without eyes, and specific receptors of electromagnetic pulses. Predator can sense electrical discharges in a millionth of a volt!
Because of the large size of many researchers believe hammerhead shark one of the most dangerous to humans. But she did not specifically attack people. Many of the attacks have taken place in front of numerous spectators, are documented. Once, in 1805, the network on Long Island were once three hammerhead shark. In the stomach, the biggest of them found a human torso.
One of the kinds of hammers - a giant shark hammer (the average length of 4-5 meters) - is brought in the International Red Book:
The whale shark - the largest species of sharks, as well as the largest of the living representatives of the fish.
Although the stories some witnesses, they encountered instances in length from 18 to 20 m, the largest ever measured specimen consisted in length 13.7 m. Weight whale sharks may be up to 12 tonnes.
Despite the impressive size it is fed like a giant shark extremely small plankton and other organisms, which filters it, sucking in water through enormous throat width which can reach 1, 5 m.
Whale sharks prefer water temperatures of 21 to 25 ° C and distributed throughout the world, occurring in almost all warm tropical and subtropical seas, many on both sides of the equator, and near it.
The whale shark is not dangerous and behaves peacefully for human beings. She not only did not attack, but even turns if a swimmer is on its way.
It has been estimated that whale sharks can live up to 100-150 years.
Galapagos gray reef shark
Usually found in tropical waters near the islands in every ocean. Sharks live in the day and prefer to stay near the shoreline near the underwater rocks and coral reefs with a strong current. These sharks reach a size of 2.5 meters.
Galapagos gray shark - one of the few, which demonstrates its intention to attack: before the attack, she arches her back, lifts his head, fins down, and during the voyage turns and rolls over from side to side. It belongs to the species dangerous to humans.
The nose sharks sensitive to certain smells and can detect the presence of blood at a concentration of 1: 1000 000, which can be compared with a tea spoon of blood, poured out into the pool.
Their other feature - curiosity sharks escorted ships, poked in the side, hit in the oars and pursue scuba divers.
The lifespan of Galápagos shark is about 24 years.
The basking shark
The basking shark is the brightest representative of the largest species of fish. This is the second largest type of fish after the whale shark. It reaches a length up to 10 meters and weighs about 4 tons.
As the whale shark, basking shark feeds on plankton, but does not absorb water, but simply floats with an open mouth, gills filtering through everything that gets in it. Thus, a huge shark able to filter up to 2000 tons of water per hour.
The giant shark found in the eastern and in the western hemisphere, preferring cool or warm temperate latitude and following the presence of plankton.
The basking shark is safe for humans and today it is under threat of extinction.
Females reach a length of 4 meters, males - 2.5 m Maximum documented weight caught bovine sharks was 316.5 kg.. The average shark bull lives 27-28 years.
Bull shark rightfully occupies third place in the list of the most dangerous species of sharks to humans. This is an extremely aggressive animal is entitled to claim to be perfect and omnipotent predator. Escape from the attacking swimmer horrible monster almost impossible.
Feeding sharks bull divers:
Attack the bloodthirsty predators usually in the morning or in the late twilight, and, often, at a shallow depth - only 0.5m - 1m.
The behavior of bull sharks can not be predicted. They can swim peacefully for a long time there, and then suddenly attack a swimmer. This attack may be as simple as a bite of research and a clear attack.
The tiger shark
This is one of the most common shark species in the world and occupies the 2 nd place in the list of the most dangerous species of sharks to humans.
Sea Tigers reach a length of 5 meters, but there are larger specimens. Weight ranges from 570 to 750 kg. The life span of tiger sharks, probably 30-40 years.
Tiger Shark Teeth:
While shark reaches two meters long, visible on its flanks transverse bands, similar to the tiger - hence the name.
Tiger sharks are found in many seas of the world's oceans, preferring to stay in the coastal waters of the tropical and subtropical seas of thermal zones. Deep tiger shark habitat range extends from the sea surface to a significant depth. They met at a depth of about 1 km.
great white shark
This huge predator rightfully occupies the 1st place in the list of the most dangerous species of sharks to humans.
The official alleged that on August 17-18, 2011 at the Maritime Territory in both swimmers were attacked by the same fish - white shark is not less than four meters in length.
"White Death" - under this name is known, this exceptionally large shark, which is found in coastal surface waters of all major oceans of the Earth. Reaching a length of over 6 meters and a weight of 2300 kg, it is the largest of modern predatory fish. Great white shark - they are like a torpedo, with a powerful tail, by which they move in the water at speeds up to 24 km / h.
Scientists have identified the size of the largest instance, the length of which has been reliably measured and is equal to 6.4 meters. This great white shark was caught in Cuban waters in 1945, measured by specialists with documentation of measurements. Unconfirmed weight of the Cuban shark is 3270 kg. (Photo Epic Hanauer):
Wide mouth and sharp teeth of triangular shape located in several rows. Experts advise the attack sharks "to strike face, in the eyes and gills." It is doubtful that these measures will help to repel 5 meter predator, millions of years of evolution has honed the skill to kill.
The number of teeth of the great white shark, like a tiger, 280-300 pieces.
However, the great white shark is on the verge of extinction - in the world of the beautiful, ancient predators there are only about 3500 copies.