24.10.2019
Species: Alopias vulpinus = Common sea fox. Common sea fox Fox find me a group shark
Big eye fox shark, or big-eyed sea fox, or big eye fox shark, or deep sea fox(lat. Alopias superciliosus) - a species of cartilaginous fish of the genus fox sharks of the family of the same name in the order Lamniformes. It lives in all temperate and tropical waters of the Indian, Pacific and Atlantic oceans. Reaches 4.9 m. Big-eyed fox sharks have an elongated upper lobe of the caudal fin, characteristic of fox sharks. The eyes are very large, in adults up to 10 cm in diameter. They have a streamlined body, a short and pointed snout. Their eyes are adapted to hunting in low light conditions. This is one of the few species of sharks that make vertical migrations during the day. They spend the day in the depths, and at night they rise to the surface to hunt.
Fox sharks hunt using their long tail like a whip. They knock down a school and stun their prey, this explains their English name. thresher shark, which literally translates to “thresher shark.” Reproduction occurs by placental viviparity. There are from 2 to 4 newborns in a litter. Embryos eat unfertilized eggs produced by the mother (oophagy).
Big-eyed fox sharks pose no danger to humans. Their meat and fins are highly prized and the species is subject to commercial and sport fishing. The low reproductive rate makes these sharks very susceptible to overfishing.
Taxonomy
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This species is also known as the common foxfish, fox shark and foxfish. The habitat extends to tropical and temperate waters. In the Atlantic Ocean, these cartilaginous fish live from Newfoundland to Argentina and from the North Sea to the southern tip of Africa. Found in the Mediterranean Sea. In the Indian Ocean they are common in its northern part. And in the Pacific Ocean, the fox shark has chosen a zone from Japan to New Zealand and from British Columbia to Chile.
This species is subject to seasonal migrations. He moves to northern latitudes along with warm masses of water. Moreover, the range of movement of males is wider than that of females. It is assumed that the populations of the Atlantic, Pacific and Indian Oceans have different life cycles. This is indirectly indicated by the fact that there are no migrations from ocean to ocean. Representatives of the species are deep-sea and live at depths of up to 550 meters. Only young sharks are sometimes found near the shore.
Description
The body is streamlined, torpedo-shaped with a short, wide head. The eyes are medium in size and lack urinary membranes. The mouth is small, its shape is curved. There are 35-52 rows of teeth on the upper jaw, and 26-49 such rows on the lower jaw. The teeth are small, triangular in shape, and have no serrations. There are 5 pairs of gill slits.
The main feature of the fox shark is its tail fin. Its upper part is very long and matches the length of the body. With the help of this powerful blade, a predatory fish stuns its prey. The pectoral fins are sickle-shaped. The dorsal fin is relatively high and is located approximately in the middle of the back. There is a tiny second dorsal fin. The pelvic fins are quite large. The skin is covered with protective placoid scales.
The color of the upper body varies from purple-brown to gray. The sides are bluish, the belly is white. In length, including the tail fin, the fox shark reaches 5 meters and weighs 230 kg. The officially registered maximum length is 5.7 meters. The estimated maximum length could reach 6.5 meters. And the heaviest caught was the female. With a body length of 4.8 meters, she weighed 510 kg.
Reproduction and lifespan
This species is ovoviviparous. Pregnancy lasts 9 months. There are from 2 to 7 newborns in a litter. They appear from March to June. They reach a length of 12-16 cm, weigh 5-6 kg and add 50 cm in length every year. Adult fox sharks grow 10 cm per year. Puberty in males occurs at a body length of 3-3.2 meters. Females mature at a length of 2.5-4.5 meters. In the wild, the fox shark lives 15-20 years. The maximum life expectancy reaches 50 years.
Behavior and nutrition
The main diet consists of schooling fish such as mackerel, herring, garfish, anchovies; squid and invertebrates are also eaten. Fish hunting is carried out individually or in groups. Sharks, with their long tails, drive their victims into a dense pile and swallow them. In addition, common fox sharks can use their tails to stifle prey. In this way they attack sea lions and seabirds. However, this happens when there are few fish. If there is a lot of it, then only it is eaten.
Conservation status
At the beginning of the 21st century, this species received the status of vulnerable. This was linked to commercial overfishing. Representatives of the species value their meat and fins. Vitamins are obtained from the liver, and the skin is tanned. Fox sharks are currently protected by law. Catch these cartilaginous fish has decreased, but poachers still cause some damage to this species.
Fox shark - most interesting representative ocean depths. This is a large cartilaginous fish whose body shape resembles a torpedo. The genus includes three species of predators. All of them have characteristic features of body structure and behavior.
What does the name mean?
The genus of sharks received its unusual name due to its long tail, or more precisely, the tip of the caudal fin. The upper segment can account for almost half the entire length of the predator. In addition to its size, the tail has another feature - the elongated lobe of the tail is flexible and movable. The British, having watched the predator hunt, gave it the most accurate name: thresher shark. It literally sounds like “thresher shark.” This is due to the unusual way of hunting.
Unusual hunt
The fox shark does not waste time on trifles: it does not chase individual victims, but prefers an abundant “restaurant” menu. During the hunt, the predator drives the frightened prey into a dense school, crashes into it and begins to “thresh” in different directions long tail. Then he leisurely dines on stunned fish. Considering the size of the predator, one can imagine the power of such a “thresher”. The fishermen who managed to catch the amazing shark complained that the fish, pulled out of its usual environment onto the deck, managed to smash and break with its tail everything it could reach.
Appearance
Since the tail is the most prominent part of this species, descriptions of the predator's appearance almost always begin with it. However, it is worth noting that the fox shark is the most impressive representative of cartilaginous fish. It has an elongated torpedo-shaped body, a wide head and a pointed muzzle. For breathing, the underwater inhabitant has 5 paired gill slits. The two outermost slits are located above the pectoral fins. The fins themselves are pointed and long. The fox shark has a small curved mouth with labial grooves. The predator's teeth are small and their edges are smooth.
The anal and dorsal fins, unlike the caudal fin, are small. There are slight differences in fin sizes and colors among different ones.
Taxonomy of species
The sea fox family is divided into 3 species:
- Alopias vulpinus, that is, the common sea fox.
- Alopias superciliosus is a deep fox shark called the big-eyed fox.
- Alopias pelagicus, a species of pelagic (small-toothed) fox.
In 1995, a fish was discovered in the waters of California, which they wanted to designate as a fourth species, but there was no confirmation of this theory, and the fourth species remained unrecognized.
Main differences. Common fox
It has a streamlined body shape with a clear curve of the back. She has a cone-shaped short head with medium-sized eyes that lack a third eyelid. The predator's teeth are small, fang-like, slightly flattened. The average size of sharks is about five meters. At the same time, a maximum was recorded - more than 7 m, and a minimum - less than four.
The shark's body color is heterogeneous. There were individuals of dark brown, blue-gray, and steel color. Some fish had a black back and a light belly.
Deep sea big-eyed fox
Despite the body structure typical of fox sharks, this representative is easily recognized by the size of its eyes. The big-eyed fox shark fully lives up to its name. In some individuals, the diameter of the eye reaches 10 cm. The peculiarity of the location of the organ in the orbit allows the predator to see not only in front and to the sides, but also to view the space above its head.
Another distinctive feature of the species is its special lateral grooves. They are formed at the junction of the body and the head, passing over the gill slits and eye sockets.
The teeth of the bigeye fox shark are larger than those of other species. They have one apex and are the same size on the upper and lower jaws.
The body color is brownish-violet, the belly is always lighter than the back. The dorsal fin is shifted towards the tail.
Pelagic fox
The color is dark: most often these are various shades of blue and gray colors. The shark's belly is much lighter.
The species has well-developed pectoral, caudal and dorsal fins. But at the same time, the second dorsal and anal fin are very small. The elongated lobe of the tail is narrower than in other species.
Habitat and diet
The fox shark has a wide range. It is found in the tropics and temperate latitudes. The pelagic species is characterized by an existence remote from coastlines. This species lives in surface layers and at depths up to 150 m.
The big-eyed fox prefers more serious depth. She is comfortable 500 m below the surface.
They love coastal zone, but they feel good and are far from the ground. This species prefers surface layers, but can dive up to 500 meters.
Fox sharks do not attack too large prey, since the basis of their diet is schooling fish. We have already talked about the hunting habits of this genus, but this does not mean that predators cannot make exceptions. In the absence of schools of fish, the diet of the fox shark can include any living creature. The person, most likely, will simply be stunned by the tail - the shark will not dare to dine on such an unpredictable enemy.
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Fox shark(second name “sea fox”, Latin name “Alopias vulpinus”) is a species of sea shark that belongs to the family Fox sharks, order Lamniformes.
Signs
Sea foxes are large sharks with an average body length of 3 meters; specimens up to 5 meters long are known. The upper part of the body is dark gray-blue, the belly is white. Average weight Fox sharks weigh 300 kilograms (maximum weight is 500 kilograms).
Distinctive sign sea foxes are their caudal fin, the upper blade of which is incredibly large, sometimes exceeding the length of the body of the fish itself. This tail is necessary for fish to hunt. Ichthyologists claim that the sea fox is capable of stunning schools of fish and even birds and small birds with its tail ladle. marine mammals. In search of food, the shark rises to the surface of the water and, seeing potential food, strikes the sea surface with its tail fin.
Habitat
Fox sharks inhabit the Pacific and Atlantic oceans. They prefer to stay in tropical waters, but often swim into waters of temperate latitudes.
Danger!!!
This type of shark does not pose a great danger to humans. However, cases of attacks by these sharks on people have been described. Sea foxes usually hunt collectively, that is, they gather in groups of 3-5 individuals and surround schools of fish, drown them with their tails, and then all together rush to the center of the fish cluster. It is during moments of collective hunting that fox sharks are most dangerous. During the chase, they rush after any moving object in the water.
Even in the depths of the sea there are workers who honestly “earn” their bread, that is, fish, fox shark or sea fox (Alopias).
Despite its large dimensions, the fox shark has no particular desire to attack a person, since it feeds on schooling fish, but if it is really hungry, it will chase after swimming invertebrates and even.
How does a fox shark hunt?
The fox shark is famous for its tail and the way it uses it: after tracking down a school of fish such as mackerel, mackerel, herring and other prey, the shark begins to circle, gradually disorganizing the prey.
With each revolution, the ring narrows, the fish huddles together, loses orientation, and the time comes to use the tail for its intended purpose: like a flail on a thresher, the shark methodically stuns the fish, after which you can calmly proceed to dinner - the stunned prey will not go anywhere for some time.
Watch video - Fox shark hunting:
Now it is clear English name fox shark (thresher shark) – thresher shark. One problem is that you need to eat a lot and at once - it is not known when luck will smile again.
The one glorified in legends comes to the rescue: the shark regurgitates what has already been chewed and greedily pounces on a new portion.
Why was the shark called a fox?
For work, that is, for food, the fox shark uses its unsurpassed tail, which, on average, occupies half the body length of the sea shark. Accordingly, if the length of a predator is 5-6 meters, then the length of the tail is 2.5-3 meters.
This is a truly formidable weapon, consisting of a greatly elongated upper caudal lobe (the lower lobe is almost atrophied), which arises from a strongly flattened caudal peduncle. With all this, its weight can reach 500 kg.
Watch video - Fox Shark Jump:
Description of the fox shark
Otherwise, the fox shark is a typical representative. The body is spindle-shaped, arched at the back. The head is small, wide and short.
The mouth is small; crescent-shaped mouth opening; , form rows, sometimes up to 20. The eyes, depending on the species, can be normal or very large. Five small gill slits, and squirt flaps may be absent.
The color is different (do not forget that there are three species in the family): gray, sometimes with a metallic sheen; gray-blue, gray-black, gray-brown - the back is always darker than the belly. Under the head and fins the color is the same as on the back.
The first dorsal fin is large, but the second dorsal and anal fins are small.
Lives almost everywhere: in the Pacific, Indian and Atlantic Oceans, in almost all tropical and subtropical sea waters.
Puberty occurs at a certain height, on average 4 meters. Quite often they live not alone, but in twos: it is believed that for joint hunting it is easier to find a school of fish and easier to suppress, working in two tails.
Watch the video - Fox shark fighting tail:
Fox shark, brings 2-4 sharks per litter. During the breeding season, it moves closer to the coast, where it stays for several months, monitoring how the water temperature affects the growing offspring.
Fortunately, the predator has no commercial value, does not like to settle on the coast, has formidable weapons and large size - all this greatly helps it not to be included in the Red Book.
True, fishermen are not very fond of the sea fox breed - while hunting for schools of fish, sea foxes get caught in nets and tear them mercilessly. Therefore, fishermen are happy to use a caught shark as bait for other fish.
The largest is the common sea fox (Alopias vulpinus), its size is 5.5-6 meters, and can be found in coastal areas.
The smallest is the pelagic fox shark (Alopias pelagicus), measuring about 3 meters, and lives in the depths away from the shore. The color is a beautiful dark blue with a whitish belly. It has smooth, wide pectoral fins.
The second species has larger eyes than the common fox, but not the same size as the big-eyed fox.
The most “beautiful” big-eyed fox shark (Alopias superciliosus) has unnaturally large bulging eyes.
And all representatives of this family are united by the possession of a magnificent fox tail!