king crab (lat. Paralithodes camtschaticus) a species of part-tailed crayfish. Scientists were able to identify about 8,000 different types of crabs. The most valuable is the king crab.
Description
He is given the 3rd place in the world in terms of fishing. They are distinguished by agility and strength when circumstances require it.
Kamchatka crab is the largest representative of crustaceans, it is also called “royal” because of its impressive size. The life of a marine inhabitant is interesting from the point of view of its biological ability to successfully undergo artificial relocation. It is of great economic importance in terms of fishing. Hermit crabs, related to craboids, are considered direct relatives.
Stand out in large sizes, up to 30 cm wide, and up to 1.5 meters long.
What does it look like
The structure of the body was formed due to the characteristics of the environment in which the crab lives, nutrition and water temperature.
It consists of shortened five pairs of legs hidden under the shell, with the help of which it moves. With the help of a short pair of limbs, it holds its shell. Having evolved, the king crab lost its shell and therefore ceased to hold it. Now with the help of the fifth pair of legs, the crab cleans the gills. Four pairs of limbs move in turn, the king crab moves very quickly, mainly to the side.
The abdomen is bent inward, shortened, its surface is dotted with small plates and micropedia. With the help of front antennas and sensitive cylinders located on them, the crab can touch and smell. Thanks to them, he identifies and searches for food.
It sheds especially strongly in the first years of life, when the frame skeleton is replaced. Then this process is much less common. The average life expectancy of a crab is about 15 20 years.
Body structure: cephalothorax under the shell and abdomen under it. Eyes are protected by armored rollers. The carapace has many protective spikes in the form of needles. The shell serves as a support for the crab, on which the muscles are attached and help it move. Lateral surfaces of the shell are equipped with gills. The chain of nerve nodes in the animal body is the nervous system. The head part consists of the stomach, and in the back is the heart. Claws have their own special tasks. To cut through the softest food or transport food to the mouth, the crab uses its left claw. To crush a sea urchin or mollusk, use the right claw. Thus, the right claw in most cases is used for hard work, t.to. it is characterized by increased size and greatest strength.
Males reach a weight of about 7 kg, a case with a width of 15 to 25 cm. The female is up to 15 cm in size, and weighs about 3 4 kg.
The shell has a red-brown color, the lateral surface is purple. Consists of gastric, cardiac and two branchial zones.
Types of king crab
Officially, the king crab is not divided into species. But there is a conditional division, based on the habitat:
Where does it live
Mostly distributed in the Pacific Ocean. Massively settles in the areas of Kamchatka, the Sea of Okhotsk and the Bering Sea. In America, found near Bristol Bay and Norton Bay.
In Norway, the authorities are drawing attention to the problems of a high population of king crab, which is crowding out indigenous inhabitants. Crustaceans cause damage to local fauna.
The crab settles in salt water, where the percentage of its content is 32%, at a temperature ranging from +2 to +7 degrees. Migrating and molting, king crabs are found in places where the water warms up to + 15 18.
What does it eat
The king crab is omnivorous, prefers to eat a variety of molluscs, plankton, worms, sea urchins, crustaceans, ascidians, small fish, starfish. Young individuals eat algae and hydroid organisms, worms. Food goal drives animals to make massive movements. With the help of powerful claws, the crustacean kills its prey. In cases of lack of live food, it feeds on cadaveric remains from fish and various organisms. The animal has a unique feature to adapt to different foods. So, waiting for a molt, the crab is looking for food containing a high level of calcium.
Its frame is highly durable and provides a high level of protection, but does not allow the body to grow between shell changes. Therefore, the crab can only grow in a short period of time, which lasts up to 72 hours. At this time, the animal sheds the old frame, and the new one lends itself well to stretching and does not prevent the crab from growing. After that, the chitin cover gradually strengthens and stiffens due to calcium salts. Then the growth of the king crab stops.
reproduction
Crabs are characterized by great migration. The chosen route of the premises from year to year remains the same. They migrate due to seasonal changes in water temperature, as well as in search of food and for reproduction. In winter, the crab dives to the bottom, to a depth of up to 300 m. In spring comes to shallow water, where it is warm and there is a lot of food.
The male reaches sexual maturity at the age of 10 years, and the female is considered sexually mature at the age of eight.
It is established that the female can lay about 300,000 eggs at a time! During the year, females store eggs on their abdominal legs. Temperature fluctuations in water determine the movement of animals. When the king crabs move to the shore, in females, the eggs have already passed into the stage of formed larvae. On a shallow shore, the larvae hatch and are already able to swim independently. At this time their moms keep moving. Very young individuals die before reaching adulthood, t.to. are a favorite prey of marine life.
Peculiarities
In summer, crabs massively rush to shallow water, and in winter they move into the depths of the ocean. Can dive to a depth of 300 m. Thanks to this feature, king crabs lead an active life and do not hibernate.
Can move at an average speed of up to 5 km per day. With mass movement along the bottom, the speed remains at the same level.
King crab is a slow growing animal, the key growth factor is water temperature. So, in America, crabs living in warm water grow much faster than in Eurasia, living in the cold waters of Kamchatka.
Eating
Crab claws are an expensive, valuable all over the world and exquisite delicacy. At the right claw, the contents are more tender and nutritious meat composition and are of the greatest value. King crab meat contains many essential vitamins, amino acids and minerals such as zinc and iodine. Meat is especially rich in protein and is indispensable for the human body. The shell and internal organs are processed as useful fertilizers.
Crab meat is rich in taurine, tocopherol, ascorbic acid, polyunsaturated fatty acids, calcium.
Benefits of eating crab meat:
Contraindications and harm
Due to high demand, multiple cases of poaching have been provoked. Due to illegal catching of crustaceans, the market is teeming with low-quality products. A person can easily get poisoned by low-quality meat containing microbes, pathogenic organisms and various infections. Such a crab may end up on your table if it does not have a quality mark check. A spoiled product can cause severe toxic poisoning, impair hearing and vision, and cause severe disturbances in the functioning of the nervous system.
In order to prevent this, it is very important to treat the place of purchase, not to look for cheap goods. In order not to buy an infected crab, you need to purchase meat in stores that have the necessary documentation. When cutting seafood, you should pay attention to the condition of cartilage, spikes, small dense elements. Care must be taken not to put the sharp part into the mouth, which can damage the esophagus and gastrointestinal tract.
natural enemies
Although the king crab is considered an animal of considerable size, it has enemies, but not many. The shell helps the arthropod defend itself. Only large marine predators can handle needles.
Who are the king crabs afraid of:
Man risks becoming the worst enemy. Taking into account the fact that in recent years the catch of the king crab has reached an industrial scale, soon uprights may become a real threat to arthropods. The Russian state has set quotas for catching the animal. The goal is to respect the population so as not to undermine the number of crabs. But poaching activities are recorded by authorities regularly.
Octopus the enemy of the king crab
Another reason that soon a person will become an enemy is the uncontrolled throwing of garbage into sea waters. Most of it does not tend to decompose this can kill crabs, despite the number.
Interesting Facts
- A distinctive feature of the Kamchatka crab is its caviar, light purple in color, reminiscent of grapes.
- In the USSR, a biological campaign was carried out to resettle the Kamchatka crab in the Barents Sea.
- King crab is exported to eastern countries, as well as large cities of Eurasia and local markets.
- They are long-lived, as they live up to 20 years. At the same time, the population is quite high, despite the high level of crab catch by fishing vessels.
- Crabs are characterized by high fecundity, which stimulates the fishery, allows it to grow from year to year, without loss in the population.
- Crab shell is recyclable, it is turned into flour, which is used in the food industry.
- The male can shed the shell in a matter of minutes, it takes him about 10 12 minutes. At such moments, he is especially vulnerable, and can become a tasty morsel for marine life.
- In a female, the change of shell can last about a week. If she has a patron who supports the female with claws and guards her, then soon he will take the place of her husband.
- The size of the head is very small compared to the rest of the body, while the stomach is located in the head.
