A blunt shark, or bull shark, is an absolutely unique creature that can cause horror even if more than half of the human victims are attributed to the representatives of this species. It was the bull shark or, as it is called in another way, the pelvis-head - one of the most aggressive predators that live in the ocean - served as the prototype of the monster from the movie "Jaws".
In addition, this is the only of 43 species of sharks that can feel great both in salt and in fresh water (for example, one of the representatives of this species was seen 4, 000 km upstream of the Amazon in South America).
What is the secret of the ability of a bull shark to live in fresh water?
In most sharks, the concentration of salt in the blood coincides with that found in seawater. And in blunt-nosed predators, by the way, it is only 50%, which causes a large outflow of water through the gills in the fresh environment and leaching of chlorine and sodium from the fish organism.
The rectal gland, liver, kidneys and gills, which are able to accumulate and then secrete the necessary sodium and chlorine, save this shark, which maintains its water-salt balance and, accordingly, facilitates adaptation in fresh water.
Researchers, by the way, drew attention to the fact that young individuals are most often found in fresh water, and adults swim here, mainly to give birth to offspring, since this tactic helps young animals to survive.
What does a bull shark look like?
The blunt shark makes an indelible impression on those who have met with it. He has a large body, while females are noticeably larger than males and can reach 4 m in length, while their cavaliers grow mainly up to 2.5 m. The weight of this shark can also be called bovine - 300 kg!
Spindle-shaped, as with all its relatives, the body of the predator ends with a massive head, with a blunt, wide muzzle and, of course, terrifying jaws.
The teeth of our "beauty" are perfectly adapted to gnawing any surfaces, even the tortoise shell. They are very sharp, have a triangular shape with strongly serrated edges and are bent inward. By the way, as soon as any of the teeth falls out, a new killing device grows in its place.
The shark is painted gray-blue, and the belly is light, almost white.
Where does the goofy shark live?
The main habitats of the bull shark are the coastal warm and moderately deep waters of the southern hemisphere (approximately 30 to 150 m depth). Her home is the Atlantic, Pacific and Indian Oceans.
But it would be more correct to call these hunters migrants, since in search of food they are able to swim in rivers and even in some lakes, where they sometimes live for several years. Amazonas, Potomac, Mississippi, Brisbane, Ganges and Brahmaputra are favorite shark rivers. More than once, a bull shark was also found in Lake Nicaragua (Central America), where it was long considered an endemic species, and in some other freshwater reservoirs with sufficient (at least 30 m) depth.
By the way, this representative of the class of cartilaginous fish is the most common species of sharks known throughout the world.
Features of the life of a bull shark
The bull shark became famous for its unpredictably aggressive behavior (for which, incidentally, it got its name) and is considered one of the most dangerous predatory fish for humans. By the way, it is the males of blunt sharks who are famous for their aggressiveness. Obviously, this is due to the fact that they live in places where you can meet a large number of swimmers or lovers of water sports.
Despite the prevalence of these fish, there are still unclear points in their behavior and life characteristics. And it is well known that this is the most socialized species among their own kind. Sometimes bull sharks hunt in pairs or in small groups in which the females clearly dominate the males, although most often they, like most relatives, prefer loneliness.
In search of food, not trying to find a fishing place, the bull shark absorbs everything that comes in its way. It can attack dolphins, and even tiger or infamous great white sharks. She is attracted by crabs, crayfish, mollusks, all kinds of fish and carrion.
Reproduction of a blunt shark
The described shark reaches puberty at 10-15 years (with an average life expectancy of up to 28 years). Her breeding season captures the last month of summer and the beginning of autumn. This type of shark is viviparous, as females hatched fertilized eggs 10-11 months in their body until they mature.
In its midst, the bull shark is the dominant predator and therefore has no enemies, which cannot be said about its offspring, and this is reflected in the peculiarities of reproduction of this fish. For example, huge swarms of pregnant females usually gather for delivery in brackish estuaries of rivers, and each produces from three to thirteen fry, whose body length does not exceed, as a rule, 60 cm. don't care. But, as mentioned earlier, in freshwater reservoirs, those forced to fight for their own life sharks are more likely to survive.
