In our article we want to talk about the famous predator - the herring shark. Have you ever heard of such a thing? She has a lot of names, including blue dog, lamna, bottlenose, mackerel, mackerel shark, porpoise, etc.
Atlantic herring shark
This shark belongs to the lamniform family of herring sharks and has a characteristic appearance for this species.
All predators of this order have five gill slits, dorsal and anal fins. They are armed with very sharp teeth, but they do not have a nictitating membrane. These are the structural features of the herring shark. The appearance of the Atlantic shark is quite ordinary for representatives of this family. The body is quite thick, spindle-shaped, the caudal fin is in the form of a crescent, the snout is sharp, conical.
The upper part of the body has a bluish-gray color (from light to the darkest shade), but the peritoneum is very light, almost white. There are no spots or stripes on the body.
The eyes are large. The teeth are quite large, triangular in shape, and in adult sharksthe base of each tooth grows a couple more small ones on both sides. Imagine that each jaw has up to sixty teeth.
A shark lives from twenty-five to thirty years.
The Atlantic herring shark reaches quite large sizes. There are facts about the existence of specimens up to 3.7 m in length with a weight of up to two hundred and thirty kilograms. However, the usual average size of a predator is from one and a half to two meters, while its weight is about one hundred kilograms.
How does the Atlantic shark live?
The lifestyle of the herring shark is no different from the behavior of other representatives of this genus. She is constantly in motion throughout her life, sometimes resting at the bottom. The shark does not have a swim bladder, which means it does not have the buoyancy that ordinary fish have. This fact makes her constantly move, otherwise she will simply drown.
Even a dead herring shark will never rise to the surface, it finds shelter at the bottom or becomes a prey for scavengers. In addition, she knows how to maintain the desired temperature of her body, which is higher than the temperature of sea water. How does she do it? The herring shark has its own thermoregulation mechanism. Everything happens quite simply. The blood in the muscles circulates through special heat exchangers, where it is heated. Thus, the shark raises its body temperature by seven to ten degrees. Such an amazing property helps predators quickly adapt to cold water and makes it possible to move faster in pursuit ofprey.
Where do herring sharks live?
The Atlantic herring shark lives in expanses of water that stretch from the Western Atlantic to Argentina and Brazil. The habitat is quite wide. In the east Atlantic, the shark is found in both Iceland and South Africa. Sometimes it can be seen in the Mediterranean Sea.
The Atlantic shark knows how to adapt well, and therefore it feels equally comfortable both in open water and in the coastal waters of islands and continents. For her, not very warm waters with a temperature of no more than twenty degrees are more preferable.
What does the Atlantic predator eat?
The basis of the shark diet is herring, and therefore the fishermen believe that if you need a herring shark, you must first find a school of fish. The predator lives at a depth of 700-800 meters from the sea surface.
Her diet includes sardines, tuna, herring, mackerel. He also does not neglect bottom fish: squid, flounder, rays, crustaceans and small sharks. The Atlantic shark is a very active and agile predator. Often these fish gather in small flocks of ten to fifteen individuals, cruising near the sea surface, exposing their dorsal and caudal fins.
This schooling habit allows them to hunt effectively, surrounding schools of fish, they drive them to the center, in a tight circle, and then start the meal. They pounce on the victim with lightning speed, greedily devouring it.
Sometimes sharks attack even fishing nets. Their unbelievablethe sight of a large number of fish caught by fishermen is stunning, then they bite through the nets, and the fish rush out, right into the mouths of greedy predators. Once, in the belly of one such shark, fifty-seven fish ranging in size from fifteen to twenty centimeters were found. Impressive, isn't it?
Atlantic shark breeding
Herring sharks are a genus of ovoviviparous predators. Fertilized eggs remain inside the fish until the birth of offspring. The embryo is surrounded by a temporary shell, which gradually disappears, and it begins to feed on the maternal secretion. It must be said that developing embryos during this period eat nearby unfertilized eggs. Pregnancy lasts eight to nine months. And in the summer, well-formed young individuals are born. Moreover, their length is from fifty to seventy centimeters. Each predator can bring two to five babies at a time.
Industrial fishing for herring sharks
The herring shark (the photo is given in the article) is not just a predator. Oddly enough, but it is an object of commercial fishing in many countries: Canada, USA, Norway, Ireland, Great Britain.
It turns out that the meat of the thunderstorm of the seas is quite tasty, although with an unpleasant specific smell. However, with proper preparation, this defect is very easily eliminated. Especially valuable are the fins, fat, liver and, of course, the skin. All parts of the fish unsuitable for food, haberdashery or medicine are sent for manufacturing.fishmeal.
Is a shark dangerous to humans?
The Atlantic shark is fast and dangerous to humans. However, there is no reliable information about her attack on people. Currently, several cases of bites inflicted by a predator have been registered. Therefore, it is difficult to talk about the degree of its danger. But in any case, it’s better to be as far away from such a predator as possible, because it’s not just that one of its names in ancient times came from the Greek expression “monster-eater”. At present, thanks to industrial fishing, the Atlantic shark is not so easy to meet. It is practically non-existent in the Mediterranean Sea, and in fact until recently there were quite a lot of it. Therefore, it is taken under protection by all-seeing ecologists as an individual that is on the verge of extinction.
Pacific shark
The Pacific herring shark is the closest relative of the Atlantic shark, from which it outwardly differs in a wide and short snout, as well as characteristic spots on the belly. In all other respects, these predators are quite similar, although they live in completely different places. The salmon variety is found only in the North Pacific.
The streamlined body is gray-blue in color. The head of the shark is large, but shorter than that of its relative. This makes it look like a small white shark. Here is such an unusual Pacific herring shark. Her structural features are such that she also knows how to maintain the desired temperature of her body, which gives her the opportunity to live in cool waters and be faster and more energetic.
Sizes of the Pacificsharks
Pacific shark reaches a fairly decent size. According to unofficial data, her body length is 4.3 meters, and the documented value is a little more modest - 3.7 meters. And the weight reaches 454 kg. These are quite serious parameters for a predator. Females are usually larger than males. An interesting fact is that in different regions of habitat there is a difference in the size of individuals. Moreover, females predominate in the east of the Pacific Ocean, but males predominate in the west. The reason for this phenomenon is unknown. Females live up to thirty years, and males - up to twenty.
Pacific shark habitat
The Pacific shark is found off the coast of Korea, Japan, in the Bering and Okhotsk Seas, in US waters, its presence has been recorded off the coast of Mexico and California. An interesting fact is that the Pacific herring shark, whose lifestyle is directly related to waters rich in food, does not sink to great depths. It will never be found below 500 meters from the sea surface.
What serves as food for Pacific predators?
Sharks feed on small fish: mackerel, herring, chum salmon, sockeye salmon, pink salmon. Their diet also includes bottom fish. In addition, the predator can afford to attack swimming birds. Gathering in flocks of twenty to thirty individuals, sharks arrange a collective hunt. The predator is so fast and agile that sometimes it even makes migratory transitions for potential food.
Pacific sharks breed in much the same way asAtlantic.
It is believed that this species is dangerous to humans, although the facts of the attack are not confirmed by documents. Nevertheless, predators are very large and aggressive, and therefore you should be careful in the regions where they live.
Some sources report shark attacks on divers, but such data has not been verified or confirmed. Moreover, this species is easily confused with others, and therefore there could be an error regarding the variety of the attacking predator.
Is Pacific predator meat edible?
Shark meat is considered tasty, and in some countries, such as Japan, and in regions of East Asia, it is generally a delicacy. However, this species of sharks is not engaged in industrial fishing. Rather, it happens by chance, while catching salmon. However, the Pacific shark is of interest for sport fishing, especially since its numbers are quite large. However, environmentalists are concerned that the fate of the endangered Atlantic shark does not await it in the future.
In Alaska, industrial fishing was banned back in 1997, and sport fishing is also quite strictly controlled. Each fisherman is allowed to catch only two fish per year.
These are such amazing creatures these sharks. On the one hand, these are formidable predators that are dangerous to people, and on the other hand, they are on the verge of extinction at the hands of all the same people. And it is not clear who should be more wary of whom. Although any predator inconditions of the wild, of course, is dangerous for humans, because you never know what to expect from him.
