A shark is perhaps the most perfect predator of the water element, which is rightfully considered the master of the oceans. But recently, in order to satisfy his whims and various household needs, man has been mercilessly trapping and destroying these fish. This can lead to an inevitable violation of the environment and a significant decrease in the number of sharks, as well as have a negative impact on the marine flora and fauna. To avoid this, many countries now impose a partial or complete ban on their fishing.
Shark species
It is impossible to answer exactly the question of how many species of sharks exist in nature. Despite the fact that people exterminate them in large quantities, 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 in the shape and size of the body, but also in the way of life. Many will be surprised to learn that sharks are invertebrate fish. They really have no bones! Instead, they have cartilage, which is a fairly stiff fibrous tissue.
Shark is a collective name. The smallest individual is only a pencil in size, and it weighs about 200 g, and the largest can reach a length of 20 m and weigh up to 20 tons.
The most famous species are the great white, reef, hammerhead, tiger, blue and polar shark, and the largest of them are giant and whale. The diet of the last two consists of plankton and small fish, which they swallow, filtering water through many small teeth. The most dangerous and aggressive is the rare white shark. In length, it can reach 5-6 m, but it happens that individual individuals grow even up to 12 m.
Habitat
The entire oceans are inhabited by various species of sharks. According to scientists, even living organisms, including deep-sea sharks, live in even the deepest hollows. Without them, it’s hard to imagine the depths of the sea and oceans.
The population density of these predators is extremely uneven. Naturally, there are more of them where there is warm water and a large amount of food, namely, off the coast.
World Ocean Population Density
The maximum number of species and individuals of sharks is concentrated in the equatorial and equatorial waters. About 80% of marine predators living here live in the surface layers at a depth of not more than 200 m. This is due to the fact that these waters are extremely rich in food.
The 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.
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 the polar (Greenland) and giant sharks.
Polar shark
It belongs to the genus Somniosidae, or Pryorythous. The polar shark is the largest representative of the Katraiformes. Some individuals of this species reach more than 6 m in length and can weigh 1000 kg. But ichthyologists are sure that this is not the limit - 8 m in length and a weight of 2 tons is quite possible. Naturally, with such dimensions, it is inactive and does not quite correspond to the image to which everyone is accustomed, namely, an energetic, swift 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 body shape is spindle-shaped, its color is from dark brown to brown with black and purple spots scattered throughout the body.
It is already clear from the name of this huge fish that it is found in the cold waters of the Atlantic and Arctic Oceans. The habitat of sharks is quite wide. 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 Baffin Sea. In the waters of the Pacific Ocean, a polar shark is widespread in its northern part, and is also found in the Sea of Japan and Okhotsk. I must say that she feels great in water with a temperature of +2 to +10 ⁰С.
Reef shark
On coral reefs, in lagoons, in shallow water and on the border with deep waters, reef sharks can often be observed. They love clear, clear water, so they rarely go down to the bottom. The optimal depth for them is from 8 to 40 m, but sometimes they fly up almost to the shore.
A reef shark is a relatively small species. Its length is a little over 2 m. It has a thin body with a flat wide head. It reaches its maximum length only by 25 years. Its color is brown or dark gray, sometimes with spots. The belly is always lighter than the back. During swimming, she makes significant wave-like movements, and can also lie on the bottom and pump gills with water, which most of her relatives can not do. We can say that she leads a settled life, as she always returns to one shelter for several years.
Since the reef shark is relatively small in size, it often becomes prey of larger and more aggressive species, such as the tiger or the belopera.
Sharks of the Red Sea
Resorts located on the Red Sea are not considered too dangerous for ordinary swimmers, divers or snorkellers. I must say that initially sharks do not consider humans as their food or prey. They prefer to keep a respectful distance from large crowds.
Sharks in the Red Sea have always been abundant, as the water in it is warm. In addition, it communicates well with the ocean. For all the time, more than 40 species of these predators were recorded in it. Off the coast of Egypt there are not so many of them; most sharks prefer the territorial waters of Sudan. In addition, not all species are dangerous to humans.
All sharks in the Red Sea, in fact, as elsewhere, are divided into pelagic and those that live in coastal waters. The former prefer open water, the latter like shallow water, especially reefs. In Egypt, they can often be seen in Sharm El Sheikh, in the Ras Mohammed Nature Reserve, as well as off the coast of Hurghada.
The greatest danger from all species of sharks of the Red Sea is black-winged, long-winged, zebra, mako and tiger.
Humans and sharks
Now often on the ocean beaches you can see signs warning that you can not enter the water. Over the past 10 years, cases of arbitrary and involuntary shark attacks on humans have significantly increased.
Scientists specializing in their study are confident that this is mainly due to the massive uncontrolled fishing of fish - the main source of nutrition for sharks. Therefore, in search of food, they are moving closer to the coasts. In addition, some of the clashes are due to the carelessness of people going out on the high seas and not observing basic precautions. Surfers and just swimming swim in the area where sharks live and hunt, which leads to inevitable clashes.
