Thanks to Hollywood, each of us imagines a shark as a ruthless killer of enormous size, chasing careless swimmers day and night. We will not argue, there are reasons for such an opinion: sharks are still predators, and hunting for game is a natural behavior for them. However, there are varieties of sharks that are absolutely not dangerous for large creatures, to which a person can be safely attributed. And there are predatory fish, which in many ways (at least in the diet) are similar to whales.
Yes, and the size of sharks in the generally accepted view is not so unambiguous. There are varieties of sharks that reach a length of 11-15 meters (in particular, large whale sharks). And there are 15-centimeter babies, dangerous only for small fish and diligently escaping from most of the larger oncoming organisms.
Shark inoverall
No matter how different representatives of this superorder are among themselves, all sharks have common features in structure, physiology and behavior:
- The skeleton of these creatures is formed not by bone tissue, but by cartilage, which makes sharks lighter, nimble and mobile.
- They all lack a swim bladder, without which most other fish cannot exist.
- They are not covered with scales, but with skin, and very tough, equipped with tiny sharp teeth. Many people and marine animals died when they encountered sharks, not from their teeth, but from accidental contact with the skin.
- Among these predators there are varieties of sharks that do not spawn, but are viviparous. However, for those who have followed the more traditional breeding path for aquatic inhabitants, the intermediate stage of development is not caviar, but rather a kind of eggs: there are very few of them (from 1 to 3), and they are protected by a very strong shell-shell. Moreover, not a fry appears from this storage, but a formed cub. So a new term "ovoviviparous" was coined specifically for sharks.
- In many species of these fish, teeth grow in several rows (from 3 to 5), which have up to 3 thousand fangs and are constantly updated. These creatures are not afraid of caries!
There is a separate question: how many varieties of sharks are known to science. The fact is that many of them have only a dozen or two representatives. And some are even presented in a single specimen registered by scientists. In principle, there are 150 varieties of sharks in the world - fromthose that have been encountered by oceanologists in many countries, and more than once. Given the endangered (mainly due to the hunting of oceanic predators) species, their number can be safely increased to 268. Some researchers believe that the figure can be raised to 450, but the rest of the species of sharks is known only from the testimony of biologists who accidentally encountered them.
Shark oddity
This "tribe" amazes scientists with its dissimilarity, and sometimes antagonism (except for the menu), which individual species of sharks exhibit. So, the fish is supposed to have a torpedo-like body shape - this facilitates hunting in the aquatic environment. But there are some types of predators described, similar to stingrays or flounders: they are looking for prey near the bottom. And others have a flat and very wide muzzle. Still others can boast of a sharp nose. But at the same time, all varieties of sharks have the main characteristic features.
Another feature: having the sharpest teeth, often continuously growing, the predator fish uses them only for attack. That is, they grab their prey and tear it, but do not chew it. That is why all its mouth filling consists exclusively of fangs - the shark does not have chewing teeth.
Shark varieties: the names of the most dangerous to humans
The abundance of these predators is very difficult to list by name. Some types of Russian-language analogues have no names at all, there are only Latin names for each species of sharks. For children and adults, however, more importantknow about the most dangerous of them, in case you have to be near the ocean, where such creatures are found.
The largest, scariest and most famous shark is the great white. It accounts for half of all human deaths from shark attacks, and three-quarters of all shark attacks. The only consolation is that this predator prefers sea lions, carrion, whales and seals. If you do not provoke her and do not get hurt in the water to the point of blood, she will swim by.
Tiger shark second place. She got her nickname because of the vertical stripes on her body. And the second reason was a bad character - the shark is aggressive and omnivorous. Again, without provocations, he will not chase a person, although he can feast on him, just out of habit, pick up everything that meets on the way.
The bull shark is recognized by oceanologists as the most aggressive of all representatives of the superorder. Worst of all, it can also enter the mouths of large rivers. Throws at everything that moves, can attack in shallow water. So if the resort warns that representatives of this species of sharks have been seen in the water, it would be wiser to get to the beach. And do not enter until they are allowed.
Terror of the Seas: Cigar Shark
From the point of view of curiosity, it is much more interesting to consider the little-known species of sharks. There is a fish from this tribe, whose length is only 42 cm, and the appearance is terrible and ridiculous. The long teeth of the cigar shark make it look like a sea bulldog. But the predator itself is terrible: it can kill an ocean dweller five times largeryourself.
Biologists call such creatures ectoparasites. They bite into the victim unnoticed by herself and eat away a significant piece of the “carrier” flesh. Large individuals stand after the attack, but those fish / animals that are comparable or slightly larger than the size of the aggressor die.
The first "cigar" was caught in 1964 in the Gulf of Mexico, and since then only a dozen of its relatives have fallen into the hands of ichthyologists. So for those who have already seen some sharks, this one is hardly familiar.
Angel Shark: Master of Disguise
This species of shark has certain reasons to be called that. And not at all because of the complaisant nature: the fish just looks innocent enough. A diver who meets her will be sure that he has come across a stingray. The "angels" move not far, hunt from ambush, and they can wait in it for hours and even days, while maintaining complete immobility.
Fortunately, "angels" are indifferent to people and do not hunt them. But if you step on a hidden hunter (and even more so try to catch it), he will respond with a lightning-fast and ruthless attack. The wounds will not be fatal, but bloody, painful, and requiring surgery.
Unique Lemon Shark
This representative of a predatory tribe is truly unique. Firstly, he can swim without harm to himself and live in fresh waters for a long time. Secondly, this shark is able to lie at the bottom for a long time - and in general it prefers to hunt at shallow depths, up to one meter. Thirdly, thanks to the coloring, it is beautifulmerges with the surrounding landscape. A man will not be eaten, but his beloved dog - without difficulty.
Unlike the angel shark, it prefers to avoid contact, but responds aggressively to attacks. However, there are very few of them left, they are found mainly in South American waters, so there is little chance of meeting her.
