When it comes to the sharks, primarily remembered for their huge toothy jaws. The spiny dogfish shark does not pose any threat to life, and is a valuable food product
Katran or korotkaia prickly shark belongs to the genus of Spiny shark, a part of the family Katrenova sharks. Other names: sea dog, rogatica, spotted spiny. Not thermophilic, inhabits cool temperate waters of the World ocean. Found off the coast of Norway and England, in a Black and far Eastern seas, is found in the Bering and White. Kept close to the coasts at depths of 100-200 meters.
As all members of the superorder of sharks have a fusiform body structure, light on the belly and darker on the back and sides color. The nose is pointed, the bottom part is sickle-shaped jaws with several rows of sharp teeth, which the shark grabs the prey, tearing off pieces. Teeth updated throughout life, replacing the dropped or ground off.
Skin like a coat of mail, covered with the special placoid scales, similar in composition to the bones and teeth. This is the oldest type scales, consisting of adjacent to each other leather plates with sharp peaks. So iron sea dog “against the grain” is dangerous.
An interesting feature of the breeding of crambe. This kind of otnositsa ovoviviparous fish, the eggs are up to four centimeters in diameter. Bearing offspring record lasts for a long time – 22 months. For spawning, the females move to the shallows with depths up to forty meters. There appear 10-20 brood size 20-25 cm, fully adapted to independent existence.
The main food for juveniles are shrimp, fish fry, small fish. Adult sharks feed on herring, sardine, mackerel, cod, etc. Squid, clams, octopus is also included in the diet. Hunting in small flocks, following the migrating schools of fish. The average life expectancy of prickly sharks is 25 years.
Along with typical symptoms, characteristic of all sharks, Katran has its own particular characteristics. Its dimensions are small: a length of five feet, weight up to 15 kg. there is No anal fin, no “third century” – a nictitating eye membrane. But most importantly, the bases of both dorsal fins have poisonous spikes, covered with mucus.
The presence of thorns and gave the name to the genus – Barbed. The cut of the cleat can determine the age of fish caught, because it has annual rings, like trees. Sharp spines should be wary of fishermen and divers. Containing the venom and bacteria, the mucus, once in the wound, causing severe inflammation.
Shark spiny dogfish is among the major predators of the Black sea. For bathing is not dangerous, but fishermen often spoils tackle and eats the catch. In the Northern and far Eastern regions, where population is numerous, is a valuable commercial fish.
All parts of the body Katran are used. Extracted from the liver of cod-liver oil. The skin, covered with sharp scales, used for polishing wood. After special treatment and removal of placoid scales of the shark skin has the texture of sharkskin famous. It is used to produce fine haberdashery. Their taste is famous for meat Katran. With proper treatment it does not have the ammonia smell peculiar to the meat of many shark. Katran fried, baked, marinated, and smoked. Among the popular gourmet shark fin soup. Used even eggs, the yolk of which is larger than the chicken. On sale shark Katran comes in canned, fresh and frozen form.
Composition and useful properties of shark Katran
In meat, liver and cartilage of crambe contains valuable nutrients required by humans. They contribute to the improvement of the body, but are not a panacea.
Meat and liver are rich in polyunsaturated fatty acids omega-3, which are indispensable for the normal functioning of the cardiovascular system and the blood. They prevent the development of atherosclerosis, reduce inflammatory processes of different localization, restore immune status. Contains micro – and macroelements: potassium, phosphorus, calcium, magnesium, iodine, sodium, chromium, zinc, etc. as well as a complex of vital vitamins, essential amino acids, easily digestible proteins.
In the liver oil of crambe contains several times more vitamin A and D than cod liver. Alkylglycerol (glycerolipid with an alkyl linkage) have immunomodulatory effects, enhance resistance to infections and fungal diseases. Squalene, first isolated from the liver of spiny sharks, regulates metabolism, promotes the excretion of cholesterol.
Preparations of cartilage Katran due to the high concentration of collagen and other substances included in the composition of cartilage, relieves the condition in diseases of the joints, arthritis, osteochondrosis, used for the prevention of cancer.
Individual intolerance. High levels of mercury typical of long-lived marine predators, is a limitation to use products from crambe pregnant women, nursing mothers and young children.