Polar shark. Habitat of sharks. Reef Shark

The shark is, perhaps, the most perfect predator of the water element, which is rightfully considered the master of the World Ocean. But recently a person, in order to satisfy his whims and various economic needs, is conducting merciless catching and destroying these fish. This can lead to an imminent violation of the ecology and a significant decrease in the number of sharks, and also have a negative impact on marine life and fauna. To avoid this, many countries now introduce a partial or complete ban on their fishing.

Types of sharks

On the question of how many species of sharks exist in nature, it is impossible to answer exactly. Despite the fact that people exterminate them in large numbers, there are more than 400 species of this fish in the world, but these are only those that are known to scientists. They differ from each other not only by the shape and size of the body, but also by the way of life. Many will be surprised to learn that sharks are invertebrates. They really do not have bones! Instead, they are cartilage, which is a fairly stiff fibrous tissue.

A shark is a collective name. The size of the smallest specimen is just a pencil, and it weighs about 200 grams, and the largest can reach a length of 20 m and weigh up to 20 tons.

The most famous species are the large white, reef, hammerhead, tiger, blue and polar sharks, and the largest of them are giant and whale. The diet of the latter two consists of plankton and small fishes, which they swallow, filtering the water through a lot of small teeth. The most dangerous and aggressive is considered a rare white shark. In length it can reach 5-6 m, but it happens that some individuals grow up to 12 m.

Habitat

The entire World Ocean is inhabited by various species of sharks. As shown by research scientists, even in the deepest depressions live living organisms, including deep-sea sharks. Without them, it's hard to imagine the sea and ocean depths.

The density of settlement of these predators is extremely uneven. Naturally, there are more of them there, where there is warm water and plenty of food, namely off the coast.

Density of population of the World Ocean

The maximum number of species and individuals of sharks is concentrated in equatorial and equatorial waters. About 80% of marine predators living here live in the surface layers at a depth of no more than 200 m. This is due to the fact that these waters are extremely rich in food.

Moderately warm sea and ocean waters are much less populated by these fish - only 16% of the total number of sharks living on the planet.

The cold and arctic seas are very scarce. Therefore, there are very few predators here. They swim in these areas only in the warm season. Such cold-resistant species are polar (Greenland) and giant sharks.

Polar Shark

It belongs to the genus Somniosidae, or Straits. Polar shark is the largest representative of the squadron. Some individuals of this species reach more than 6 m in length and can weigh 1000 kg. But scientists-ichthyologists are sure that this is not the limit - 8 m in length and weight of 2 tons is quite possible. Naturally, at such sizes it is inactive and does not fully correspond to the image to which all are accustomed, viz., An energetic, impetuous and ruthless predator. The polar shark is completely non-aggressive, and even if it gets into the net, it behaves calmly, like a log.

It looks ordinary and unattractive: the shape of the body is spindly, the color is from dark brown to brown with black and purple spots scattered all over the body.

Already on one name of this huge fish it becomes clear that it is found in the cold waters of the Atlantic and Arctic oceans. The habitat of sharks is wide enough. It can be found off the coast of Iceland, Norway and Greenland, as well as in the northern seas of Russia. In addition, it is found in the Hudson Bay and in the Sea of Baffin. In the waters of the Pacific Ocean, the polar shark is common in its northern part, and also occurs in the Sea of Japan and the Sea of Okhotsk. I must say that she feels great in the water with a temperature of +2 to +10 ° C.

Reef Shark

On coral reefs, in lagoons, in shallow waters and on the border with deep waters, reef sharks can often be observed. They like pure clear water, so very rarely go down to the very bottom. The optimal depth for them is from 8 to 40 m, but sometimes they are almost to the shore itself.

The reef shark is a relatively small species. Its length is little more than 2 m. It has a thin body with a flat wide head. Its maximum length it reaches only to 25 years. Its color is brown or dark gray, sometimes with spots. The belly is always lighter than the back. During the voyage, she makes significant wave-like movements, and can also lie on the bottom and pump water with gills, which most of her relatives do not know how to do. It can be said that she leads a sedentary life, as she always returns to one shelter for several years.

Since the reef shark is relatively small, it often becomes the prey of larger and more aggressive species, such as tiger or whitecrack.

Sharks of the Red Sea

Resorts located on the coast of the Red Sea, are not considered too dangerous for ordinary bathers, divers or divers with a mask. It must be said that initially sharks do not consider humans as their food or prey. They prefer to keep a respectful distance from a large crowd of people.

Sharks in the Red Sea were always abundant, as the water in it is warm. In addition, it is well communicated with the ocean. For all time in it more than 40 kinds of these predators have been registered. Near the coast of Egypt, they are not so many, most of the sharks prefer the territorial waters of the Sudan. In addition, not all species are dangerous to humans.

All sharks in the Red Sea, in fact, as everywhere else, are divided into pelagic and those that live in the coastal waters of water. The former prefer open waters, the latter - like shoal, especially reefs. In Egypt, they can often be seen in Sharm el-Sheikh, in the Ras Mohammed reserve, as well as off the coast of Hurghada.

The greatest danger from all kinds of sharks of the Red Sea is represented by the black-winged, long-winged, zebra, mako and tiger.

People and sharks

Now often on the ocean beaches you can see signs warning that you can not go into the water. The last 10 years, there has been a significant increase in the number of arbitrary and involuntary shark attacks per person.

Scientists specializing in their study are sure that this is mainly caused by massive uncontrolled fishing - the main source of food for sharks. Therefore, in search of food, they are moving closer to the coasts. In addition, part of the collision is due to the carelessness of people going to the open sea and not observing the elementary precautions. Surfers and simply swimmers swim in areas where shark dwell and hunt, which leads to inevitable collisions.

Causes of the attack

Why do terrible sharks attack people? This happens for several reasons. The first of these is curiosity. All animals are by nature such, including sharks. And they show their curiosity through a trial bite. So, as a person touches his fingers to the object of interest, so these fish try everything on the tooth. Unfortunately, their touch is much more painful and unpleasant than touching your fingers.

Food competition is the second cause of the attack. A large number of individuals in the vicinity also claim an unknown object. Fearing for the interception of prey, a predator without undue doubt attacks and snatches out some part of the flesh. This often occurs during the so-called periods of food fever in sharks.

The third reason is the protection of the territory. Like animals, sharks guard their water area from uninvited guests. Especially aggressively protect their territory gray sharks, which all their appearance, or rather, grimaces and poses, show that you'd better retire, or else it will attack without warning.

The last reason is cannibalism. At the same time, sharks deliberately attack people, since they have tried the human flesh on taste. These cases, of course, are rare, but by outward signs it is impossible to determine whether the predator is a cannibal.

Everyone knows that there are super deep depressions in the seas and oceans, where man has not been able to visit yet. Therefore, there may well be hidden many mysteries and interesting and unusual inhabitants of the depths. The cold waters of the Arctic Ocean, in our opinion, are of little use for life, but there are also many living creatures, including sharks.