Kamchatka crab belongs to the type of arthropods, subtype of crustaceans, and the genus of craboids. Outwardly, it looks like a real crab, but in terms of taxonomy it is closer to hermit crabs. It lives in the Japanese, Bering and Okhotsk seas. It can migrate to the Barents Sea.
Kamchatka crab - the most impressive in size among crustaceans. The main parts of the body are the cephalothorax, covered with a shell, and the abdomen (abdomen). The female differs from the male in a more developed abdomen. He has no tail. There is no internal skeleton either; its role is played by a shell, additionally protecting it from enemies.
The gills are located under the shell on the sides, the heart in the back, the stomach in the head. There are 11 large spines in the carapace above the stomach, and only 6 above the heart. The crab has 4 pairs of legs that are clearly visible, and the fifth pair is hidden under the carapace. It serves not to move, but to clean the gills. On the front pair of legs, claws are most developed. The crab uses the right claw to break shells of mollusks and shells of sea urchins, and the left - to cut sea worms.
Kamchatka crab has a dark red shell with a purple hue, for which it is called red. The inside of the shell is yellowish white. The mass of a large male can reach 7 kg, the width of the shell is 28 cm, the span of the middle legs is 1.5 m. They can live up to 20 years if they are not caught and eaten. The enemies are people, octopuses, bulls, cod, sea otters, etc.
Kamchatka crabs annually pass along the same route and migrate. In winter, they spend at a depth of about 250 m, and in the spring they move in shallow water to shed and breed. In the fall they go back to deep water. A change in water temperature serves as a signal for movement. Crabs do not move alone; many, thousands, hundreds of thousands of them move. Moreover, large males are kept separate from young animals and females. For a year, crabs wind up to 100 kilometers along the seabed.
Adult crabs molt once a year. Shedding lasts 3 days, these days the males hide under the stones, burrow into the pits. Together with the carapace, their intestines, esophagus, stomach walls, and tendons are renewed.
Having replaced the shell, the female releases caviar (eggs can be from 20, 000 to 445, 000) under the abdomen. She bears her 11.5 months. The following year, moving in shallow water, the larvae emerge from the eggs, and the females continue to move. The female lays eggs once a year, and the male can mate with several females during the breeding season.
Kamchatka crabs mature late, females reach maturity at 8 years old, and males at 10 years old. Their ritual of courtship is unusual. Holding on to each other with claws, they can stand for 3-7 days. The female assists the male in the process of molting, then mating occurs.
Larvae survive a little, about 4%. At first, the larva swims in the water, and moves due to the movement of the jaws. Then settles at the bottom, living in algae. Only by the age of three she leaves her habitat, having managed to shed several times. Begins to migrate at 5-7 years.
Kamchatka crab - an object of profitable fishing, but recently limited due to their reduced numbers. King crab meat is a valuable dietary product, a delicacy containing vitamins A, PP, C, group B and trace elements. Right claw is most valued. The shells and entrails also go into business, they make excellent fertilizer from them.
