Kamchatka crabs are one of those inhabitants of our planet that have long become an object of close attention, both from the planet’s leading specialists and from ordinary fauna lovers. And this is perhaps not surprising. The animal is actually unusual and quite rare today.

Unfortunately, there are still those representatives of the human race for whom Kamchatka crabs are just one of the lines on the menu of an expensive restaurant.

We are not at all trying to preach or promote vegetarianism. To eat or not to eat animals is, undoubtedly, everyone’s business. However, after reading the proposed sections, the reader, if desired, will be able to reconsider his views on the surrounding reality, for example, by learning what characteristic features has a live king crab where it lives, what it eats and how it reproduces.

Section 1. Where do these animals live?

Basically, the name speaks for itself. Even the most incurious reader will immediately realize that this type of crab is found en masse in Russia, namely off the coast of Kamchatka.

Although not everyone knows that it is also found in Primorye. Among other things, it can be found in the territory from Posiet Bay to the Pacific coast of Canada, if you move through the northern part of the Japanese Sea to the Okhotsk and Bering Seas along the Aleutian Islands.

Section 2. What does it look like?

The Kamchatka crab (in Moscow, St. Petersburg and other cities of central Russia it can only be seen in the zoo) is a fairly large species of crustacean.

By the way, it is not uncommon for him to be mistakenly classified as an ordinary representative of this species. This is nothing more than an unfortunate misconception. Why? The thing is that it has one significant difference: instead of five, this creature has four pairs of legs, so it would be more correct to classify it as a craboid.

The shell and phalanges of the Kamchatka crab are brown, have purple spots on the sides, and the abdomen is yellow-white.

The Kamchatka crab can live 20 years. Surprisingly, in rare cases adult the width of the shell grows to 20-25 cm, and the weight can reach 7 kg. On average, there are males with a shell of 15-16 cm and a weight of 2.5 kg.

The females of this crustacean are much smaller in size and weight. They are distinguished by semicircular shapes, a fairly wide abdomen, under which almost all year round egg development occurs. But the abdomen of males more closely resembles a symmetrical triangle.

Section 3. What do they eat?

Kamchatka crabs are real predators. They feed on mollusks, polychaetes, echinoderms, small sea acorns and many other bottom animals.

The claws of the Kamchatka crab are quite powerful. With them, he effortlessly tears apart the prey, then, using his legs and jaws, grinds it and sends the food into his mouth.

As a rule, the right claw is larger in size; it is used to break mollusk shells and crush skeletons sea ​​urchins, but the left one is used by the crab only for grabbing.

Section 4. Where do they winter?

Perhaps the answer to this question cannot but interest me. But in fact, where does the animal spend time during the cold season?

The wintering grounds of crabs are located relatively far from the coast, where the depth reaches 110-200 meters. Kamchatka crabs do not hibernate; they lead exactly the same active lifestyle in winter as in summer.

They have to go deeper due to the lower water temperature in shallow water and the formation of ice. In the spring, as soon as the sea bays are cleared of ice, crustaceans begin to move to smaller areas. It is interesting to note that during this period, male and female king crabs move towards the shore in separate groups. This can be explained simply: female crabs carry last year’s developed eggs on their abdominal legs. Halfway through the adults' journey to the shore, the larvae hatch.

Section 5. How do Kamchatka crabs reproduce?

About a month after migration, shoals of female and male individuals mix in shallow water, and the mating period begins. Moreover, female Kamchatka crabs at this time look far from beautiful: a dirty shell overgrown with shells, empty shells from eggs completely covering the abdominal legs. But the males do not pay attention to this, they choose their girlfriends, pinching the females’ claws with their claws. Couples remain in this “handshake” position for 3 to 7 days.

After this, the males help the females molt - they pull off the females' contaminated old shell, and then attach spermatophores to the bases of their third pair of walking legs.

It should be noted that after mating, females and males again migrate separately, going in search of food.

Before the summer migration, males also molt, but alone among the stones. After a while, the female lays eggs, fertilizing them from the spermatophore. The female carries the eggs on herself until next spring.

Section 6. Why is this type of animal valuable?

Kamchatka crabs, or rather, their tender meat, are highly valued by gourmets for their excellent taste, minimal amount of calories, high content of mineral elements, zinc, iodine, vitamins, and amino acids.

The most valuable are caviar and meat located in the area of ​​​​the legs, claws and the articulation of the legs with the body. From a medical point of view, dishes made from this crab are often recommended to be consumed to improve vision, as well as for anemia and various cardiovascular diseases.

Section 7. How to cook Kamchatka crab?

Properly cooked Kamchatka crab, photos of which can be seen on the menus of the most luxurious restaurants on the planet, has the most tender meat and a subtle aroma of sea freshness.

Is it possible to try it, as they say, at home? Surely! Not everyone knows that there is a simple and sufficient quick way cooking crab that everyone can handle. So, first of all, this crustacean should be boiled in very salty water, and to improve the taste, it is recommended to add allspice, carrots, leeks, onion, celery root and even wine. How to calculate everything correctly? Very simple. For example, for a crab weighing 1.5 kg, you need to take a pan that can hold at least 30 liters of water and 4 liters of wine.

You need to cook it for at least 15 minutes, but at the same time, when cooking, it is important to ensure that the crab is not overcooked, otherwise its meat will resemble rubber more than a delicious delicacy.

Kamchatka crab, photos and detailed description dishes from which are found in almost all cookbooks is great way surprise even the most picky gourmet guests.

Naturally, when setting the table, you cannot do without a beautiful presentation of the dish. For example, why not place the prepared crab on a dish along with herbs to make the delicacy look as if it were alive? Tempting? By the way, please note: it is advisable to first cut the crab shell near the claws. This will make cutting it much easier.

Kamchatka crab (lat. Paralithodes camtscaticus) is one of the most major representatives family of hermit crabs (lat. Lithodidae). The span of its legs can reach 1.8 m, and its weight exceeds 7 kg. Due to its impressive size and valuable meat, it is also called king crab.

Spreading

Original habitat was in the Bering Sea and northern waters Pacific Ocean. In the 60s of the twentieth century, Soviet scientists resettled part of the population to the Barents Sea near Murmansk. For this purpose, aviation was used, since transportation by rail turned out to be ineffective. The animals died after just two days in transport tanks.

The species successfully acclimatized to new conditions, and 30 years later began its active spread towards the coast of Norway.

It persistently captures new territories at a rate of about 50 km per year. Currently, its numbers off the northern coast of Europe have increased so much that it poses a threat to the continued existence of many local species of marine fauna. According to various estimates, it now amounts to 120-140 million individuals.

In Norway, excessively proliferated crustaceans are called “Stalin’s crabs.” Last years Norwegian activists are persistently demanding that their government take decisive action and stop the growing expansion of Far Eastern settlers. Biologists do not share such calls, believing that it will stop on its own.

Commercial fishing

Industrial fishing of king crab in Norway began in 1994. It runs from October to December. Its volumes are controlled by Norwegian-Russian agreements, according to which only males are allowed to be caught. For catching, special boxes are used that can accommodate up to a hundred animals. They rarely end up in fishing nets and in small quantities, so they continue to be considered an exquisite and expensive delicacy.

They are supplied to the retail chain in live, frozen and boiled form. Both whole specimens and legs and claws are sold separately. Fresh king crab weighing about 3 kg in EU countries costs up to 300 euros.

Crab meat contains everything nutrients, which are necessary for human body. It is especially rich in proteins, B vitamins and selenium, which has a strong antioxidant effect and prevents the development of cancer.

Features of physiology

The Kamchatka crab feels comfortable at water temperatures from 1.5° to 11°C at depths from 4 to 300 m. It annually makes seasonal migrations to deeper waters in the winter months and returns in early spring in shallow waters for procreation. Adults prefer muddy or sandy seabeds, while larvae tend to settle near the shores in dense aquatic vegetation, where they can hide from predators. Males like colder water; at 1.7°C they spend the least amount of energy.

From mid-June to mid-November, the entire population moves to a depth below the summer jump layer (thermocline).

When bad weather rages in the surface layers of the sea due to their strong heating and wind mixing, crustaceans enjoy peace and quiet at the bottom. To start molting, the water must warm up to 8°C. In such conditions it begins, but goes slowly. Rapid molting occurs at 12°C, so crabs are forced to constantly migrate to warmer areas to undergo it safely.

Juveniles can live in waters with low salinity, while adults require a higher concentration of salt.

Because of their large sizes and the fragility of the exoskeleton in young animals, the concentration of sodium and potassium ions in the hemolymph is relatively low and increases as the body matures and the exoskeleton thickens. This allows large crabs, with increased or decreased salinity, to respectively increase or decrease the osmotic pressure inside the body.

When the water acidity is 7.8-8 pH, the growth of crabs slows down. If acidity long time exceeds these values, the animal will die due to a violation of acid-base homeostasis.

For breathing, five types of gills are used, located in the gill chamber inside the carapace. Their surface is covered with chitinous cuticles with partially permeable membranes that carry out gas exchange based on diffusion. The opening to the gill chamber is located at the base of the walking legs. Water is removed from it through a hole in the front of the lower edge of the carapace. In air, the crab can live for a short time, extracting oxygen from the moisture present in the gill chamber.

Nutrition

King crabs, like many other crustacean species, are omnivores. Cannibalism is common among them, and they willingly eat their weaker and smaller relatives.

With their right claw they tear the victim into pieces, and with their left they eat its meat.

The basis of the diet is shellfish, sea ​​stars and hedgehogs. Algae and various representatives of benthic fauna are also eaten. Carrion is considered a special delicacy. Feeding can be done at any time of the day. Maximum activity occurs in the evening and at night.

Reproduction

The mating season begins in early spring. Obsessed with the idea of ​​procreation, males cease to see only food in females and are filled with the highest feelings towards them. They spend many days in a row with them, driving away competitors and taking care of their health. A noble gentleman can even for a long time guard the entrance to the shelter, where the lady of his heart is undergoing another molt.

After the eggs are fertilized, the ardent suitor loses interest in his beloved and goes home. The female lays from 25 to 40 thousand eggs, which are placed between the stomach and tail in a special protected pouch on her walking legs. She constantly moves them so that there is a constant flow of fresh water to the eggs. Their gestation lasts about 11 months.

The hatched larvae immediately leave the mother and hide in the thick of aquatic vegetation. Two weeks later they migrate from shallow waters to the deep sea.

At this time, their body length ranges from 50 to 70 mm. The larvae feed mainly on plankton. The next spring they already resemble their adult fellow tribesmen. They shed very often, which leads to rapid growth. Sexual maturity occurs no earlier than 6 years of age, after which growth slows down, and molting occurs only once a year.

Description

The width of the carapace of adult individuals reaches 20-25 cm, and the span of the limbs is 150-180 cm. Average weight 6-8 kg. Some especially large specimens weigh 10-12 kg. Color changes depending on age, habitat and nutrition. It can be reddish, reddish brown, brownish, golden yellow or bluish.

The shell on the back is covered with multiple spines. There are six walking legs and two claws, which also have spines. Red stripes run through them. There are many small brown spots on the belly. Small notches are clearly visible on the front of the shell.

The tip of the rostrum is pointed and armed on top with one large spine and a pair of small spines. At the base of the outer antenna there is a movable spine (scaphocerite). The right claw is larger than the left. The lifespan of the Kamchatka crab reaches 30 years.

Origin and description of the species

The Kamchatka crab (Paralithodes camtschaticus) owes its name to its external resemblance to crabs, however, according to the zoological classification, it originated in the process of evolutionary development from hermit crabs belonging to the Craboid family, the general genus Paralithodes.

The main difference from crabs is the fifth pair of walking legs that is shortened and hidden under the shell, as well as irregular shape, with chitinous scutes, an asymmetrical abdomen in females. A short pair of limbs in hermit crabs serves to hold the shell. In the process of evolution, the Kamchatka crab stopped living in a shell and therefore the need to hold it disappeared. The fifth pair of legs is used to clean the gills.

The crab moves with the help of four pairs of limbs, moving them in turn. It moves at a fairly high speed, the direction of movement in this species is to the side.

The abdomen, bent and shortened, has small plates and microlegs, the asymmetrical arrangement of which confirms the origin of the arthropod from species in which the abdomen is twisted in a spiral shape.

Video: Kamchatka crab

The senses of touch and smell are provided by the front antennae with sensitive cylinders located on them. This species feature has significant influence on eating behavior, helping in the search and choice of food.

As the individual grows, a change in the frame skeleton occurs, or molting. The frequency of molting at the beginning of life, especially during the development of larvae, is high and occurs much less frequently, up to 1-2 per year in an adult, and by the end of life it happens only once every two years. How often crabs should molt is regulated by special glands located on the eyestalks. Before shedding the old frame, the soft parts of the arthropod are already covered with a still weak, pliable shell. The Kamchatka crab lives on average about 20 years.

Appearance and features

The crab's body consists of two parts - the cephalothorax, located under a protective shell, and the abdomen, folded under the cephalothorax. The eyes are protected by an overhanging shell or beak. The carpax has sharp protective spine-like spines, 6 of which are located above the heart and 11 above the stomach area.

In addition to the protective function, the shell also serves as a support and exoskeleton, because muscle fibers that carry out movements are attached to it from the inside. On the lateral surfaces of the frame shell there are respiratory organs - gills. Nervous system represented by a chain of interconnected nerve nodes located on the underside of the cephalothorax and abdomen. The heart is located at the back, and the stomach is located at the head.

Of the five pairs of legs, the crab uses only four to move. The reduced fifth pair is hidden under the shell and is used to clean the gills.

Interesting fact. The use of claws in the Kamchatka crab differs in the nature of the function performed. With its left claw, the crab cuts softer food, and with its right claw it crushes hard food - sea urchins that live on the bottom, the shells of various mollusks. The claws differ in size; the right one is larger, performing more difficult work.

In males, the width of the body varies from 16 to 25 cm and the weight reaches 7 kg. About 1.5 m is the distance between the ends long legs in the largest individuals. Females are smaller in size - body up to 16 cm, weight on average 4 kg. The female is also distinguished by the presence of a round and irregularly shaped abdomen.

The color of the Kamchatka crab shell is red on top with brown tint, on the side surfaces there are areas and inclusions in the form of specks of purple color, below the color of the crab is lighter - from white to yellowish.

Where does the Kamchatka crab live?

Wide distribution is noted in the northern part of the Pacific Ocean, where arthropods of this species are more abundantly found in the Kamchatka region in the Sea of ​​Okhotsk, as well as in the Bering Sea. The crab also lives off the American coast in Bristol Bay, Norton Bay and near the Aleutian Islands. In the Sea of ​​Japan, habitat is noted on the southern side.

Interesting fact. Biologists of the Soviet Union developed and carried out the relocation of the species to the Barents Sea.

New environmental conditions are different from familiar conditions natural habitat(lower water salinity, temperature ranges, annual temperature changes). The theoretical preparation process took place since 1932, induced by the main goal of achieving economic profit from fishing in its waters, avoiding high competition from Japan and other countries.

The first attempts to transport crabs were carried out by rail and were unsuccessful - all individuals died, the travel time was long, it took more than 10 days. After this, in the 60s, air transportation was carried out, occupying short time. This is how the first batches of arthropods were delivered and acclimatized. Later, in the 70s, transportation took place in specially equipped cars and was the most successful.

Currently, as a result of the process of invasion, an independent population unit with a high replenishing and self-regulating population has formed in the North Atlantic. There is an industrial catch of large males. Catching juveniles and females is prohibited.

What does the king crab eat?

The food for this species is very diverse and the crab is inherently an omnivorous predator.

Food objects are all inhabitants of the seabed:

• various shellfish;
• plankton;
• worms;
• sea ​​urchins;
• crustaceans;
• ascidians;
• fish small sizes;
• sea ​​stars.

The young feed:

• algae;
• hydroid organisms;
• worms.

During their lives, representatives of this species make mass movements for food purposes. Moving from one ecosystem to another, the dominant species in a particular system become food.

Powerful claws serve as an excellent tool, and the crab easily obtains the necessary food. Moreover, when killing the prey, the crab does not eat it completely, and most of its mass is lost. Crabs also eat the corpses of fish and other marine organisms, acting as a water purifier. After the introduction of the crab into the waters of the northern seas, there is still no clear opinion about the impact of the settler on local biosystems as a whole.

Some scientists criticize the experiment, fearing for the presence and numbers of native species of inhabitants of the northern seas, with which the Kamchatka crab competes in nutritional needs and on which it feeds. After all, by consuming certain types of organisms en masse, the crab can lead to their depletion and even extinction. Other scientists speak favorably of the results of the introduction, emphasizing economic benefits.

Interesting fact. At different periods of his life cycle arthropods have preferences for different foods. For example, an individual that is about to molt in the near future preferably chooses organisms with a high calcium content, such as echinoderms, as food.

Features of character and lifestyle

The strong frame of the arthropod, serving as protection and support, at the same time prevents growth between the moments of its change. The animal grows only in a short period (usually no more than 3 days), when the old hard frame is discarded, and the new one, still soft and pliable, does not interfere with its rapid increase in size. After a growth spurt, the chitinous cover is intensively impregnated with calcium salts and overall growth stops until the subsequent molt.

The frequency of shell changes varies over the course of life:

• up to 12 times after the formation of the larva during the year;
• up to 7 times, less often in the second year of life;
• 2 times during the year during the period of life from the third to the ninth year of an individual’s life;
• 1 time from the ninth to the twelfth years of life;
• Once every two years, from the age of thirteen until the end of your life.

During molting, the animal tries to find shelter in depressions or rock cracks, as it becomes defenseless without a strong frame.

Interesting fact. Molting affects not only the outer cover of the crab, but also renewal internal organs- the membranes of the esophagus, stomach and intestines are renewed. The ligaments and tendons with which muscle fibers are attached to the exoskeleton are also subject to renewal. Cardiac tissues are also renewed.

A representative of this species is a rather active arthropod, constantly performing migratory movements. The route of movement does not change, repeating itself every year. The reason for migration is seasonal changes in water temperature and the availability of food, as well as the reproductive instinct.

So, with the onset of winter, the crab sinks along the bottom into deep waters within 200-270 m. With warming, it returns to the warm shallow waters filled with food. Crabs migrate en masse, gathering in groups of varying numbers. Males are ready to breed when they reach ten years of age and females are seven or eight years old.

Social structure and reproduction

After the onset of spring, males begin their journey to shallow water. Females move in the same direction, but in separate groups. The female carries already ripe eggs on legs located near the abdomen. Closer to shallow water, larvae emerge from the eggs and are carried away by the current. By this time, new eggs have already been formed in the female’s genital organs, which are yet to be fertilized.

With the beginning of molting, individuals of both sexes come closer and form a characteristic pose - the male holds the female with both claws, reminiscent of shaking hands. The holding continues until the end of the moult; sometimes the male helps the chosen one to free herself from the old frame. After the completion of molting (on average from three to seven days), the male releases a ribbon with germ cells - spermatophores, which is attached to the female’s legs. The male, having completed the mission, leaves and also moults.

After some time (from several hours to several days), the female spawns eggs (from 50 to 500 thousand), which, when they meet the male’s ribbon, are fertilized. A special sticky substance collects the eggs together and attaches them to the villi on the female's abdominal legs, where they undergo a development cycle until the following spring, for 11 months. The female spawns eggs only once a year, in the spring, but males can mate with several females.

The larvae that have just hatched from the eggs remain in the water column for about two months and are transported by the current; at this stage of development, up to 96% of the larvae die. Afterwards, the surviving larvae sink to the bottom, into algae thickets, where they live for three years. They molt frequently and go through several stages of development. Then the young individuals move to sandy bottom areas. Migration begins after reaching 5 years of age, sometimes 7 years of age.

Natural enemies of Kamchatka crabs

Adult large representatives of the species have few natural enemies, since the crab has excellent protection - a reliable and durable shell, which in addition is covered with sharp spine-like needles. Only large ones marine mammals able to overpower an adult crab.

Smaller individuals have a greater number of enemies, among them:

• predatory fish;
• Pacific cod;
• halibut;
• marine;
• bulls;
• octopuses;
• large crabs, different types(intraspecific cannibalism is noted).

During the molting period, the crab becomes absolutely vulnerable and is forced to seek shelter. Man is not one of the natural enemies of the species, however, given uncontrolled commercial fishing and poaching, man has every chance of becoming a species enemy. Therefore, quotas for catching royal arthropods are determined at the state level in order to use population reserves as carefully as possible without undermining their numbers and ability to recover.

Human activity indirectly negatively affects sea ​​creatures, in particular Kamchatka crab. Industrial chemical waste, plastic, and petroleum products pollute the vast seas and oceans, negatively affecting all flora and fauna. As a result, entire species are vulnerable to depletion or are on the verge of extinction.

Population and species status

King crab migration occurs in groups of individuals, with females and males moving separately, meeting only once a year, in the spring, for mating. Juveniles also move separately, creating groups of young. The size of the crab population in the Kamchatka region is this moment significantly reduced, for the same reasons of large-scale and uncontrolled commercial fishing.

In the Barents Sea, where the species was artificially introduced, the situation is the opposite. Thanks to the absence of many natural enemies regulating numbers, the royal arthropod quickly spread throughout the coastal territory of the Barents Sea. According to rough estimates, the population size in 2006 was more than 100 million individuals and continues to grow.

The polyphagous predator quickly exterminates the indigenous species of many crustaceans, mollusks and others, which rightly raises concerns among many biologists for the continued existence of a stable ecosystem in the Barents Sea.

Since 2004, Russia began commercial fishing. Allowable fishing volumes are determined each year based on the current situation in the estimated population size.

Kamchatka crab An interesting arthropod with a special development cycle. Representatives of this species have successfully completed the process of introduction and acclimatization into the northern Barents Sea. Scientists predict differently how this invasion will affect the integrity of the marine ecosystem in the future.

For those who saw Kamchatka crabs for the first time in their lives, these animals make a great impression.

In terms of its size, the Kamchatka crab is an outstanding representative not only of decapods, but also of all crustaceans. Character traits The structures of crustaceans, reproduced in the Kamchatka crab on a large scale, are strikingly striking even with the most superficial glance at this animal.

The width of the shell of the average male Kamchatka crab is about 16 centimeters, the span of its legs is almost 1 meter, and its weight exceeds 2 kilograms. The largest specimens reach 25 centimeters in carapace width, one and a half meters in leg span and 7 kilograms in weight.

The body of the Kamchatka crab consists of a cephalothorax, covered with a common shell, and a belly, folded under the cephalothorax. Therefore, if you look at a crab from above, only its shell and legs are visible. A powerful shell with large sharp spikes reliably protects the animal and, in addition, serves as a support for the muscles. The shell, like that of the crayfish, fuses with the body only on the back, and on the sides it lags behind the walls of the body and hangs down like the sides of a jacket, covering the gills. The gills in the resulting cavities are protected from damage and at the same time are easily washed with water. In front of the cephalothorax are attached two pairs of antennae, eyes on stalks, jaws and legs. The front edge of the shell is armed with a sharp outgrowth that protects the eyes.

The abdomen of the crab, always tucked under the cephalothorax, in females bears special appendages for bearing eggs. The abdomen contains the intestines and internal genital organs. The first pair of crab legs is armed with powerful claws, three next couple serve for movement, and the last pair of reduced legs is always under the shell and is used to clean the gills. The muscles of the walking legs are very well developed.

What do Kamchatka crabs eat?

Kamchatka crabs are predators. They eat marine bottom polychaetes, mollusks, amphipods, echinoderms, small sea acorns and other bottom animals. The crabs tear their prey with their claws and, using their legs and jaws, crush, grind and send it into their mouths. The right - large - claw is used to crush shells of mollusks and skeletons of sea urchins. With its left claw, the crab can tear only soft prey. Very interesting experiments were carried out to find out what sense guides crabs in search of prey. Food was lowered into a large aquarium where Kamchatka crabs were kept. The animal immediately reacted to the smell with characteristic movements of the antennae and began searching for prey. The crab cannot determine the direction to the prey by smell, so it begins to move slowly, feeling the bottom with the ends of its claws. The crab lowers its claws vertically downwards and, touching the ground with the ends of its claws, quickly opens and closes them, as if snapping scissors, to see if anything gets caught. These probing movements are very energetic and "nervous".

The crab searches blindly, describing the most incredible loops along the bottom of the pool. As it approaches the feeder, when the smell of food intensifies, the crab becomes very excited and probes the bottom with its claws even more often. However, even in close proximity to the food (for example, at a distance of 1 centimeter from the end of the claws to the food), the crab repeatedly misses and moves away from it again. This suggests that the crab's sense of smell and vision are poor helpers, and it finds its prey only through touch.

Finally, the crab probes for food with the tip of its claw and quickly grabs it with one claw or both at once. In search of prey, animals lost an unusually large amount of time, doing unnecessary a long way.

Kamchatka crabs spend their entire long lives wandering, repeating the same route every year. The Kamchatka crab is an exclusively running animal and is completely unsuited to either swimming or burrowing into the ground. The crab cannot burrow, because then its open gills can become clogged with silt. Powerfully developed leg muscles allow you to cover long distances. The crab runs both forward and sideways, alternately throwing out and bending its walking legs. The claws of the feet act like pegs stuck into the ground. The body is supported by weight when walking. The speed of movement of Kamchatka crabs in a straight line reaches 2 kilometers per hour. However, the crab usually moves in zigzags, and the distance it travels per day does not exceed 10-13 kilometers. Individual crabs wander in different directions, and the speed of movement of the entire school is only 2-4 kilometers per day. Crab shoals move throughout the year within their migratory area. The size of such areas for one school is almost 200 kilometers. Some crabs stray from their schools and move into schools in neighboring areas. The reason for such transitions is strong competition for food. Animals often move to areas where fishing is more active. There, the number of crabs drops significantly due to fishing, and competition for food decreases.

Where do Kamchatka crabs winter?

The wintering grounds of crabs are located quite far from the coast at depths of 110 to 200 meters. In fact, the crab does not hibernate, but continues to lead the same active lifestyle in winter as in summer. The departure to depth is explained more low temperatures water in shallow waters and ice formation. In the spring, when the bays of the sea are cleared of ice, the crabs move to shallower areas. During this period, males and females of the king crab stay in separate herds and move to the shore in parallel paths. Female crabs carry eggs on their abdominal legs, which have been developing since last year, and halfway through the adult crabs' journey to the shore, a mass hatching of larvae occurs. The fully developed crab embryos in the eggs, whose translucent eyes gave them the name “caviar with eyes,” tear the shells of the eggs into two halves and float up into the water column.

Reproduction of Kamchatka crabs

About a month after the start of migration, schools of males and females meet in shallow waters and mix. The mating period begins. The females at this time look very unpresentable: a dirty shell overgrown with barnacle shells, empty egg shells on the abdominal legs. Nevertheless, the males choose their mates and clamp the claws of the females with their claws. Couples can remain in this “handshake” position for 3 to 7 days. Then the males help the females molt by pulling off the contaminated old shell from them, and attach spermatophores to the bases of the third pair of walking legs of the female. After this, the partners separate. After some time, the female lays eggs on her abdominal legs, which are fertilized from the spermatophore and which the female carries on herself until next spring.

After mating, the schools of females and males again migrate separately, now the crabs go in search of food and feed all summer. Before the summer migration, the males molt, but in complete solitude, hiding among the underwater rocks. During the feeding period, crab schools gradually move from one field to another with average speed about 4 kilometers per day, destroying significant amount bottom animals.

Where do Kamchatka crabs live?

The largest quantity of Kamchatka crab, as its name suggests, is found off the coast of Kamchatka, as well as in Primorye. Its distribution area goes from Posyet Bay through the northern part Sea of ​​Japan, through the Sea of ​​Okhotsk and most of the Bering Sea along the Aleutian Islands to the Pacific coast of Canada.

Hello, dear aquarists!

I have already talked about freshwater shrimp and crayfish. It's time to introduce you to the freshwater crab. So!

King leopard crab(Parathelphusa pantherina) is a freshwater crab that has absolutely no need for land areas: it is perfectly confined to the bottom! No, he can climb onto land, but he does this extremely rarely.

The appearance of a leopard crab in an aquarium rightfully evokes admiration and attracts the observer’s eye: of course! Just look at the colors: the crab is painted in the perfect combination of pastel colors - the beige color of the carapace (that is, the “boxes”, the body) and claws, and is all strewn with dark brown dots. The spectacle is amazing!

By the way: it is precisely because of the ideal combination of color and dots that the color of the crab is very similar to the body color of a leopard, hence the name - leopard. And the crab received the name “King” for its size: the diameter of the carapace (“box”) is 5 centimeters, the width is 3-4 centimeters, and the length of the entire crab - including the claws - reaches 15 centimeters! Well, why not His Majesty?!

The king leopard crab is native to Indonesia. In nature, it lives in reservoirs, with a fairly high hardness reaching 8 (Ph), at a temperature of +28*C. But they can also live in cooler water +20*C: the main condition is not lower than +20*C.

In an aquarium, the crab does not need acidic water: neutral water and low hardness are sufficient - only 10*.

leopard crab

An aquarium for a crab should be equipped in the same way as for a crayfish: driftwood, stones, empty pots - all this is used as shelter and housing.

You should not put several male crabs in one aquarium: they will fight and fight until they die! The optimal solution: one male and two or three females.

The food for the leopard crab in the aquarium should be complete and varied. Under the concept " good nutrition» means shrimp meat, pieces of frozen or boiled sea ​​fish(fillet), chicken (fillet), plants (lettuce leaves that need to be chopped, pieces of zucchini, cucumber). In general, both protein and carbohydrates should be present. It is highly recommended to add eggshell powder to the crab diet: this is calcium, which crabs need to form a new shell during the molting period.

By the way, about molting. This period in the life of a crab that lives in natural conditions sharply different from the period of a crab living in an aquarium.

The fact is that in natural conditions, the crab prepares for molting at the hormonal level, since in nature everything is clearly predetermined: both the temperature of the water and its parameters (acidity, aeration, etc.). There are no such conditions in an aquarium: only you create them! Yes, friends: in the aquarium you act as Neptune and everything depends only on you and your attention.

Therefore, you need to know the following:
First of all, with crabs you never turn off!
Secondly, you cannot overfeed the crab, since the crab begins to excrete more waste products, thereby poisoning its own habitat (well, if you don’t take it to the toilet, it will leave with the tide in the toilet).
Thirdly, at the moment of molting, the crab should not experience.

How to find out? Simple: ask him! Joke. You won't need to find out if you follow simple rule: rational nutrition is the key to health and longevity. This means that you need to feed the crab twice a day: for example. In the morning they gave him a piece of meat, and in the evening - a piece of cucumber. The next day, in the morning they gave me boiled fish or shrimp, and in the evening - lettuce leaves and a piece of zucchini.

Keep the bottom clean: remove waste in a timely manner.

And finally, a warning: although the leopard crab does not like land, it can still get out of the aquarium, and how! Therefore, if you don’t want to spend half a day looking for it, then close the aquarium with a lid.

That's all. I hope you liked the article. Let me take my leave for now. See you in the next articles!