Which group does the Kamchatka crab belong to? King Leopard Crab (Parathelphusa Pantherina). Calories and nutritional value

In the waters of the seas washing the shores of the Far East of our country, a creature called the Kamchatka crab lives. It belongs to the phylum of animals – crustaceans. Although the animal looks like a crab, scientists still classify it as a member of the hermit crab family, believing that its biological essence falls precisely under this category.

We won’t argue with them, but just find out more closely what kind of cancer this is, called the crab.

What is the appearance of Kamchatka crab?

It is believed that this is one of the largest representatives of crustaceans. The width of the shell is approximately 25 centimeters, and if the crab opens its legs, the distance from one leg to the other will increase to one and a half meters! The average individual Kamchatka crab weighs about 7.5 kilograms (although females are almost twice as light). The entire body of the animal consists of a fused head and chest (cephalothorax), covered with a large shell. The animal has no tail.

Inside, the crab is structured as if backwards: its heart is located in the back of the body, and the stomach, on the contrary, is in the head. The animal has ten limbs in total, but uses only eight legs to “walk”. The remaining two legs are used as a "device" for cleaning the gills.

The shell and limbs of the animal are dark red, sometimes even with a purple tint, and the abdominal part is yellowish-white.

Where does the animal live?

His territory of residence is considered to be the northern regions of the seas washing the Far Eastern region, namely: the Kamchatka region, the territory of the Shantar and Kuril Islands, the shores of Sakhalin Island, the northern territory of the Sea of ​​Japan, Bristol Bay, the Sea of ​​Okhotsk and the Bering Sea.

Lifestyle of the Kamchatka crab

In the marine environment it lives at depths from 2 to 270 meters, choosing a flat sandy or mud bottom for living. This crab cannot be called sedentary; it constantly migrates, but always along the same route.

In the cold season, it sinks deep to the bottom - up to 200 meters, and after wintering it rises to the upper layers of water warmed by the spring sun. Molting in these animals (adults) occurs once a year, and not only the outer shell (shell) changes, but even the walls of the internal organs (heart, esophagus and stomach).

In the natural environment, these creatures can live 15–20 years.

What does the Kamchatka crab eat?

The main food for this crab are worms, sea urchins, small fish, plankton and a variety of shellfish.

Mating season and offspring of the Kamchatka crab

The breeding season for these marine inhabitants occurs at the beginning of spring. After mating games, the male and female mate, as a result of which the female lays a huge number of eggs (up to 400 thousand!).

From the eggs small larvae emerge, only the size of a small fly. A “newborn” crab has no legs, and in general it is poorly protected. That is why the larva settles to the bottom, in thickets of underwater plants, and lives there for about two months. Three years after birth, the small crab moves from its old “place of residence” and begins to live on sandy soil. When a baby king crab turns 5 to 7 years old, it begins the migration process.

Who are the natural enemies of the king crab?

These underwater inhabitants become prey for sea otters, cod and other fish, gobies, and hairy quadrangular crabs. But the first place in the extermination of this species undoubtedly belongs to man.

What are people's interests? Why do they hunt these sea creatures?

The answer is obvious - a person is ready to uncontrollably consume everything that brings him benefit and benefit. So Kamchatka crab was no exception because of its valuable, incredibly tasty and healthy meat. Massive catching, which lasted for a long time, led to a sharp reduction in the number of this species of marine animals. Therefore, strict state control has now been established on the production of Kamchatka crabs. Unfortunately, this ban did not affect the activities of poachers, and they still, breaking the law, catch these sea creatures for profit.

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. The characteristic structural features of crustaceans, reproduced in the Kamchatka crab on a large scale, are strikingly striking even at 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, the next three pairs are used for movement, and the last pair of reduced legs is always under the shell and is used for cleaning 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 crabs are guided by in their search for 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 the 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, the animals lost an unusually large amount of time, traveling an unnecessary long distance.

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 move to depth is explained by lower water temperatures in shallow waters and the formation of ice. 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 at an average speed of about 4 kilometers per day, destroying a significant number of 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 Posiet Bay through the northern part of the Sea of ​​Japan, through the Sea of ​​Okhotsk and most of the Bering Sea along the Aleutian Islands to the Pacific coast of Canada.

Titles:king crab, king crab, red king crab, giant king crab .

Area: northern regions of the Far Eastern seas. Kamchatka, Shantar Islands, Bristol Bay, Okhotsk and Bering Seas, the shores of Sakhalin, the Kuril Islands, the northern part of the Sea of ​​Japan (Peter the Great Bay and the coast of Hokkaido).

Description: Kamchatka crab is one of the largest species of crustaceans. It looks like a crab, which is why it got its name, but in reality it is closer to hermit crabs. The body consists of a cephalothorax, which is covered with a common shell, and a belly (abdomen). The abdomen is tucked under the cephalothorax, and looks like a tail, which the crab does not have. The shell protects the crab from enemies and serves as a support for the muscles. There is no internal skeleton. At the leading edge of the crab's shell is a beak that protects the crab's eyes. The nervous system (chain) of the crab stretches along the underside of the body. The female differs from the male in having a more strongly developed abdomen. The male's abdomen is almost triangular. The lateral edges of the shell cover the gills, which are washed by water. The crab's stomach is in the head, and the heart is in the back of the body. Six large spines stick out on the shell above the heart, and eleven above the stomach. Eight legs are involved in locomotion, including legs with claws. The fifth pair of legs is reduced; the crab hides it under its shell and uses it from time to time to clean its gills. With its right claw, the Kamchatka crab crushes the shells of mollusks and sea urchins, and with its left claw it cuts worms and other soft animals.

Color: On top, the shell and legs of the Kamchatka crab are dark red (red-brown), with a purple tint. Yellowish-white underneath.

Size: in large males the width of the cephalothorax is up to 25 cm. The leg span is up to 150 cm.

Weight: male - up to 7.5 kg, female - 4.3 kg.

Lifespan: 15-20 years.

Habitat: depths from 2 to 270 m. Leveled areas of the shelf with sand or mud.

Enemies: humans, octopuses, gobies, cod, hairy quadrangular crab, sea otter, fish (sculpin).

Food/food: bottom invertebrates (molluscs, starfish, urchins, sea urchins, especially the flat sea urchin Echinarachnius, worms), fish, crustaceans, zoo- and phytoplankton. Fingerlings feed on hydroids.

Behavior: Kamchatka crab migrates regularly (speed up to 1.8 km/h). Every year it repeats the same route. In winter (off the western coast of Kamchatka) it goes to a depth of 110-200 m. In spring, in schools (large males separately from females and juveniles) they rise from the depths to warmed shallow water. Adult crabs molt once a year. Molting lasts about three days (all this time the crab hides in holes at the bottom or crevices between rocks). During molting, the crab not only changes its shell, it also breaks away from the old walls of the stomach, esophagus, and intestines. Renews all tendons. Molting females are guarded by males. After molting, females and young males move to shallow water, and adult males move deeper into rich food fields.

Reproduction: during molting, remaining in a new soft shell, the female releases dark purple eggs under her belly. Later, in the summer, the eggs become brown, and the following spring you can already see the eyes of the embryos in each egg. One female lays up to 20-445 thousand eggs. Next spring, on the way to shallow water, the larvae emerge from the eggs, and the females continue on their way. Each year, the female lays eggs once, while the male can mate with several females (up to 11) during the entire breeding season.

Breeding season/period: in Primorye: March-April.

Puberty: females - 8 years, males - 10 years.

Courtship ritual: the female stands in front of the male and holds his claws with her claws. The crabs can remain in this position for up to 3-7 days. The female helps the male molt, after which mating occurs.

Pregnancy/incubation: 11.5 months.

Offspring: The crab larva is the size of a fly, it has a long abdomen, an oblong smooth shell with three spines along the edges. There are no legs. Swims with the help of its jaws, its long abdomen plays the role of a rudder. The first two months the larva lives in the water column, then it molts and settles to the bottom, where it lives in thickets of ahnfeltia algae. Mortality from the moment of birth to settling to the bottom reaches 96.5%. After birth, crab juveniles go through several stages of development. After three years, the crab larva leaves the shelter (during this time it molts several times) and moves to areas with sandy soil. At the age of 5-7 years it begins to migrate, the width of the shell reaches 43-69 mm. More than a hundred kilometers pass along the bottom in a year.

Benefit/harm for humans: Kamchatka crab is the most valuable commercial species - a source of delicious and dietary meat.

Population/Conservation Status: The number of Kamchatka crab has been greatly reduced, so its fishing is limited.

Literature:
1. State Darwin Museum of Natural History (http://www.museum.ru/darwin/)
2. Technology of crab farming in the Far Eastern seas Zh. No. 1 1998 (http://www.partnerregions.org/)
3. V. Fedorov. Kamchatka crab

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King Leopard Crab(Parathelphusa Pantherina)
Latin name: Parathelphusa Pantherina
Other names: Panther Crab, Freshwater King Crab.

Habitat

In nature, the king leopard crab lives in fresh water reservoirs located in Indonesia.

Appearance and gender differences

The color of the leopard crab is very unusual and beautiful. The light beige body is decorated with a scattering of dark brown spots, which is how this species got its name. The king crab is not very large: its body, including its claws, reaches 12 cm in length, and its carapace is 4 cm in length and 3 cm in width.

Conditions of detention

The king crab can hardly be called peace-loving. This animal prefers to stay isolated and have a personal territory that it does not want to share with other members of its family. Crabs of this species are recommended to be kept in families, which usually consist of 2-3 females and one male. But if you plan to place several males in one aquarium, then it is important for each of them to provide a territory of at least 30 cm² in order to prevent the manifestation of intraspecific aggression, which often ends in self-harm and death of pets. Also in the aquarium you need to place a large number of various shelters, for example, ceramic pipes, clay shards, caves, grottoes and driftwood, so that each of the pets has a personal shelter and the opportunity to retire.

The leopard crab does not need sushi, so it feels quite comfortable in a regular aquarium. Although, if desired, you can keep your pets in an aquaterrarium with islands of land protruding above the water in the form of driftwood and stones. King crabs tend to escape outside the aquarium. They leave the tank quite quickly, using aquarium equipment for this purpose - cords, hoses, tubes, etc. Taking this into account, it is important to ensure that the aquarium with pets is always covered, be it with glass, mesh or a lid, which will prevent the escape. Unlike other types of crabs, which live on land for months and can freely do without a body of water for a long period, the leopard crab spends most of its life under water, only occasionally getting out onto land. Therefore, the animal’s gills dry out quite quickly, which, of course, can cause the death of the pet.

Molting is one of the most difficult periods in the life of a crab, and how quickly the pet adapts after it largely depends on the conditions of detention, for example, on the quality of food, temperature conditions and even lighting intensity. It is worth noting that crab molting occurs exclusively in water, so it is important that it is not contaminated with waste products. Therefore, care should be taken to filter and aerate the water. The water parameters in the aquarium must correspond to the conditions in the natural habitat: temperature - 25–28 ° C, hardness - about 10 °, pH - approximately 8.0 (a slightly alkaline or neutral environment is needed, but in no case acidic, since it prevents hardening of the chitinous cover, which can have a detrimental effect on the pet).

It is important to ensure that your crab aquarium contains a sufficient number of live aquarium plants of all kinds, as this provides the crabs with a more complete nutritious diet. Indeed, in addition to specialized feed and food of animal origin, the king crab also needs plant food, on which the normal growth, development and health of pets depends.

The Kamchatka crab (Latin: Paralithodes camtscaticus) is one of the largest representatives of the family of hermit crabs (Latin: 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

The original habitat was in the Bering Sea and the northern waters of the 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.” In recent years, Norwegian activists have been 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 all the nutrients that are essential for the 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 to shallow waters in early spring to reproduce. 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.

Due to their small size and 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 the acidity exceeds these values ​​for a long time, 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 mollusks, starfish and urchins. 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 is even able to guard the entrance to the shelter for a long time, where the lady of his heart undergoes 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 limb span is 150-180 cm. The average weight is 6-8 kg. Some particularly 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.