Contents
Katran is also called sea dog (Sgualus acanthias), but it is better known under the name “katran”. The shark represents the “katranovye” family and the “katranovye” detachment, which are part of the genus of spiny sharks. The habitat of the family is quite wide, since it is found in the temperate waters of all the world’s oceans. At the same time, the depth of habitation is quite impressive, about one and a half thousand meters. Individuals grow in length to almost 2 meters.
Shark tar: description
It is believed that the katran shark represents the most common shark species known to date. Shark, depending on the geographical point of its habitat, has several names. For example:
- Katran ordinary.
- Common spiny shark.
- Spiny short shark.
- A blunt-nosed spiny shark.
- Sand katran.
- South katran.
- Marigold.
The katran shark is an object of both sports and commercial fishing, due to the fact that its meat does not have the specific smell of ammonia inherent in other types of sharks.
Appearance
Compared to other shark species, spiny sharks have a more streamlined body shape. According to many experts, this form is more perfect when compared with the forms of other large fish. The maximum body length of this shark reaches a size of about 1,8 meters, although the average size of a shark is slightly more than a meter. At the same time, males are smaller in size compared to females. Because the core of the body is cartilage and not bone, it weighs significantly less, regardless of age.
The katran shark has a long and slender body, which allows the predator to move easily and quickly in the water column. The presence of a tail with different lobes allows the shark to carry out various quick maneuvers. On the body of a shark, you can see small placoid scales. The back and lateral surfaces of the predator are dark gray in color, while these parts of the body often have small white spots.
The shark’s muzzle is characterized by a characteristic point, and the distance from its beginning to the mouth is about 1,3 times the width of the mouth itself. The eyes are located at the same distance from the first gill slit, and the nostrils are slightly shifted towards the tip of the snout. The teeth are of the same length and arranged in several rows on the upper and lower jaws. The teeth are quite sharp, which allows the shark to grind food into small pieces.
The dorsal fins are shaped in such a way that rather sharp spikes are located at their base. At the same time, the size of the first spine does not correspond to the size of the fins and is much shorter, but the second spine is almost equal to the height, but only of the second dorsal fin, which is somewhat smaller.
Interesting to know! In the area of uXNUMXbuXNUMXbthe head of the katran shark, approximately above the eyes, one can see fairly short processes called lobes.
The shark does not have an anal fin, and the pectoral fins are impressive in size, with somewhat concave edges. The pelvic fins are located at the base, projected by the location of the second dorsal fin.
The most harmless shark. Shark – Katran (lat. Squalus acanthias)
Lifestyle, behavior
The katran shark navigates the vast water areas of the seas and oceans thanks to its sensitive lateral line. She is able to feel the slightest vibrations that propagate in the water column. In addition, the shark has a well-developed sense of smell. This organ is formed by special pits that are connected directly to the throat area of the fish.
The katran shark feels its potential prey at a great distance. Due to the excellent aerodynamic characteristics of its body, the predator is able to catch up with any underwater inhabitant included in the diet. In relation to humans, this species of sharks does not pose any danger.
How long does a katran live
As a result of the observation of scientists, it was possible to establish that the katran shark is able to live for at least 25 years.
Sexual dimorphism
It is possible to distinguish females from males, except in size. Therefore, we can safely say that sexual dimorphism in this species is poorly expressed. As a rule, males are always smaller than females. If females are able to grow up to one and a half meters, then the size of males does not exceed one meter. It is possible to distinguish the katran shark from other types of sharks by the absence of an anal fin, regardless of the sex of the individuals.
Range, habitats
As mentioned above, the habitat of this predator is very wide, so it can be found anywhere in the oceans. This relatively small species of sharks is found off the coast of Japan, Australia, within the Canary Islands, in the territorial waters of Argentina and Greenland, as well as Iceland, both in the Pacific and Indian Oceans.
These predators prefer to inhabit temperate waters, therefore, in too cold waters and in too warm waters, these predators are not found. At the same time, the katran shark is capable of making rather long migrations.
Interesting fact! The katran shark or sea dog appears closer to the surface of the water only at night and only in conditions when the water temperature is about +15 degrees.
This species of sharks feels good in the waters of the Black, Okhotsk and Bering Seas. Predators prefer to stay close to the coastline, but when they are hunting they can swim far into open waters. Basically, they are in the bottom layer of water, sinking to a considerable depth.
Diet
Since the katran shark is a predatory fish, various fish, as well as crustaceans, form the basis of its diet. Often the shark feeds on cephalopods, as well as various worms that live in the bottom soil.
There are cases when the shark simply swallows jellyfish and also eats seaweed. They can follow flocks of forage fish over long distances, especially in relation to the Atlantic coast of America, as well as to the eastern coasts of the Sea of Japan.
It is important to know! Too many spiny sharks can cause serious damage to fisheries. Adults spoil the nets, and also eat fish that have fallen into the nets or on hooks.
During cold periods, juveniles, as well as adults, descend to a depth of up to 200 meters, forming numerous flocks. As a rule, at such a depth there is a constant temperature regime and a lot of food, in the form of horse mackerel and anchovy. When it is warm or hot outside, katrans can hunt whiting in whole flocks.
Reproduction and offspring
The katran shark, compared to many bony fish, is a viviparous fish, so fertilization takes place inside the fish. After mating games, which take place at a depth of about 40 meters, developing eggs appear in the body of females, located in special capsules. Each capsule can contain from 3 to 15 eggs, with an average diameter of up to 40 mm.
The process of carrying offspring takes a long period, so pregnancy can last from 18 to 22 months. Before the birth of fry, the shark chooses a suitable place, not far from the coastline. The female gives birth to 6 to 29 fry, up to 25 cm long on average. Young sharks have special cartilaginous covers on spines, so at birth they do not cause any harm to the female. Immediately after birth, these sheaths disappear on their own.
After the next birth, new eggs begin to mature in the ovaries of the female.
In colder waters, juvenile katran sharks are born somewhere in the middle of spring; in the waters of the Sea of Japan, this process occurs at the end of August. After being born, shark fry for some time still feed on the contents of the yolk sac, in which the main supply of nutrients is concentrated.
It is important to know! Young sharks are quite voracious, as they need enough energy to breathe. In this regard, juvenile katrans swallow food almost constantly.
After being born, shark fry begin to lead an independent life and get their own food. After eleven years of life, the males of the katran become sexually mature when their body length reaches about 80 cm. As for the females, they are able to breed after a year and a half, when they reach a length of about 1 meter.
Shark katran. Fishes of the Black Sea. Squalus acanthias.
All types of sharks are distinguished by the presence of intelligence, innate power and cunning of a predator. Despite such facts, the katran shark has natural enemies, more powerful and more insidious. One of the most feared predators living in the world’s oceans is the killer whale. A serious influence on the number of this shark is exerted by a person, as well as a hedgehog fish. This fish, falling into the mouth of a shark, stops in its throat and is held there with the help of its needles. As a result, this leads to starvation of this predator.
Population and species status
The katran shark is the representative of the underwater world, which is not threatened by anything these days. And this, despite the fact that the shark is of commercial interest. In the liver of a shark, scientists have identified a substance that can save a person from some forms of oncology.
Useful Properties
The meat, liver and cartilage of the katran shark contain a lot of useful components that have a positive effect on the functioning of the internal organs of a person. It should be remembered that these components are not a panacea.
In meat and in the liver, there is a sufficient amount of Omega-3 polyunsaturated fatty acids, which have a beneficial effect on the functioning of the cardiovascular system and the circulatory system. Omega-3 fatty acids help reduce the risk of heart disease, reduce the risk of various inflammatory processes, stimulate the immune system, etc. In addition, the meat contains trace elements, as well as a whole complex of vitamins and amino acids, including easily digestible proteins.
Liver fat of katrans is characterized by a large amount of vitamins “A” and “D”. There are more of them in shark liver than in cod liver. The presence of alkylglycerides contributes to the immune modulation of the body, increasing its resistance against infections and fungal diseases. For the first time, squalene was isolated from the shark liver, which takes part in the body’s metabolic processes and promotes the breakdown of cholesterol. The cartilaginous tissue of the katran shark contains a high concentration of collagen and many other components. Preparations made on the basis of cartilaginous tissues help in the fight against diseases of the joints, arthritis, osteochondrosis, and also for the prevention of the appearance of malignant neoplasms.
In addition to benefits, the katran shark, or rather its meat, can also harm a person. Firstly, in case of individual intolerance, it is not recommended to eat the meat of this shark, and secondly, which is typical for long-lived marine predators, the meat contains mercury, which limits the consumption of meat for such categories of people as pregnant and lactating women, small children , the elderly, as well as weakened people as a result of a severe illness.
In conclusion
Given the fact that a shark is a strong and huge predator, negative associations arise at the mention of them and a person imagines a huge mouth, literally dotted with sharp teeth that are ready to tear any prey to pieces. As for the katran shark, it is a predator that has never attacked a person, which means it does not pose any danger to him. At the same time, it is a valuable food object, which cannot be said about other, similar predators.
What is interesting is that all parts of the body find their use. The skin of a shark is covered with sharp scales, so it is used for polishing wood products. If the skin is processed using a special technology, then it acquires the texture of the famous shagreen, after which various products are made from it. Katran meat is characterized as tasty because it does not smell of ammonia if it is properly cooked. Therefore, meat can be fried, boiled, baked, marinated, smoked, etc. Many gourmets prefer shark fin soup. Shark eggs are also used, which have more yolk than chicken eggs. You can buy shark meat in canned, frozen or fresh form.