Kamchatka crab. Lifestyle and habitat of the Kamchatka crab

The king crab is actually a crayfish, but got its name due to its external resemblance to crabs. Its name also clearly indicates its habitat. It is distinguished by its short fifth pair of legs, hidden under its shell. Also, female Kamchatka crabs have an asymmetrical abdomen and chitinous scutes. A direct relative of this type of cancer are hermit crabs, together with which they belong to the craboid family. Initially, this arthropod had a shell, and it needed a fifth pair of legs to hold it. But in the process of evolution, the shell became unnecessary, and the fifth pair of legs remained. But even now it has practical significance, it is used to clean the gills.

How do crustaceans molt?

In the life of any crustacean there is one extremely important, quite complex and entertaining process, without which growth and development are impossible.
This is a molt. Crustaceans molt many times throughout their lives, some frequently, some less frequently. Daphnia molt up to several times a day, while crayfish and crabs molt from a couple of times a month when young to once every few months and even years when adults and old people. Molting occurs more often the more actively the crustacean’s body develops.

First of all, the importance of molting is due to the presence of an exoskeleton in crustaceans. In other words, a shell. All muscles are attached to the shell from the inside; it protects the animal’s internal organs from damage by external forces, primarily predators. But at the same time, the shell limits growth - after all, it is hard and cannot stretch. Animals with internal skeletons - vertebrates - reach enormous sizes, like thirty-meter blue whales or forty-meter lizard-hipped dinosaurs, and they can become so precisely because the development of the skeleton does not prevent an increase in body weight. It is interesting that the largest invertebrates - cephalopods - also turned out to have an external skeleton, a shell, and have only its rudimentary remnant, which is also located inside the body and serves to attach muscles.

The vast majority of crustaceans have to molt in order to grow. The same thing, however, happens in insects and arachnids, although a little differently. Molting occurs approximately like this (I will omit the physiological and biochemical details; they are in biology textbooks).

First, the crayfish or crab looks for a secluded place where no one will disturb it for at least several hours. Fortunately, this does not always happen, and in a calm environment, a living animal can shed in the open, allowing us to film (or just see) this process.

After the shelter is found, its skin bursts at the junction of the cephalothorax and the first abdominal segment. Over the past few days, a new layer of young exoskeleton has been forming under the old shell, gradually separating from the old layer. After the new layer is completely formed, the old one is separated from it and through the gap between the scutes, which move apart, the soft body of the cancer is thrown out by powerful muscle contractions. In crabs, this process occurs more slowly and is somewhat reminiscent of squeezing toothpaste out of a tube - there is no single powerful jerk, there is a long sequence of small contractions.

After the body of a crayfish or crab has left its former skeleton, it is very soft and tender, and the animal is absolutely defenseless against possible predators. Over the next few hours, the cancer will sit motionless, and amazing processes will take place in its shell. To begin with, the internal organs, having the opportunity to spread out to the sides, straighten out, the muscles stretch the still elastic skeleton to the sides and it becomes larger than before. All this time, the animal’s body is soft, whitish, practically uncolored, actively absorbs minerals from the water, primarily calcium, and gradually hardens. During the hardening process, it also acquires characteristic pigmentation. After complete or partial hardening of the skelea, the crustacean usually leaves the molting site and looks for a new shelter. Some species stay in place to eat their own old skeleton - it contains a lot of calcium and proteins, primarily chitin.

In all crustaceans, the process of reproduction is also associated with molting. The first pair of abdominal legs of males are transformed into reproductive organs, which the male introduces into the female’s body to fertilize her eggs. But the male can introduce them only before the female’s body has completely hardened. Therefore, before mating, the female, ready for it, molts, and the males gather, attracted by her smell and, possibly, pheromones released at the moment of molting or shortly after it. There is a rather subtle point here - the male should come only when the female’s body hardens so much that it can no longer be crushed or eaten. Crustaceans are mostly solitary animals, and predatory species can easily profit from a molting fellow.

Another interesting phenomenon in the world of crustaceans is also associated with molting. This is limb regeneration. If in a fight or battle with a predator a crayfish, crab or shrimp loses one or even several of its limbs, it will not cost them their lives: the lost leg or claw will gradually form under the old shell and, with a new molt, will begin to grow back little by little. At first it will be very small and non-functional, but after two or three molts it will completely restore its size and function.

Below we show the molting process that Tasha observed in her red Florida crabweed (Procambarus clarkii var. Orange). This female, having been purchased at the Moscow Pichy market under the guise of a completely different animal - a dwarf orange crayfish (Cambarellus patzcuarensis), shed almost continuously for several months - every two weeks, or even more often. And it quickly outgrew the 4 cm allotted for dwarf crayfish. Adult Florida crayfish easily reach 15 cm in length.

Short description

In its structure, indigo is a unique representative of crustaceans. The carapace is blue, the legs are orange, the claws are gray/blue, the abdomen is white with blue veins. The size of an adult reaches twenty centimeters, the male has a brighter color than his female. The animal spends all its free time searching for food; not finding food, it goes into the forest thickets. This feature distinguishes indigo from other representatives of the crustacean family, which go to the ocean in search of food.

• homeland - West Africa;
• for keeping in captivity you need an aquarium 60 x 45 x 45 cm;
• food - meat, vegetables, fruits;
• night beast;
• reproduces by eggs;
• the shell is changed once every 1 – 1.5 years;
• females live 8 – 10, males – 6 – 7 years.

The crabs received the nickname “patriot” for a reason; they love to protect their territory. If there are two males in the aquarium, they will not get along, as they will share the territory. But they fight hard and can die.

Distinctive features

1. A striking feature is their colors. Their shell is blue, the claws are gray or blue, the paws are orange to bright red, and the abdomen is white and blue. Males are brighter in color than females.
2. Lives on average 10 years and grows about 20 cm, although this is rare in captivity.
3. Another feature is that these crabs look for food on land, not in water.

The sex of individuals is determined by the shape of the abdomen (abdomen): in females it is wide, in males it is narrow.

Cardisoma armatum is the scientific name of this beauty. It is also called rainbow, indigo, blue-red, red-blue, tricolor, terrestrial. For his love and protection of his home and territory, he was nicknamed the patriot crab.

Features of crab care, brief description

Patriots can be kept in an aquaterrarium under conditions of the coastal zone of at least 1/3 of the total size of the tank. It is not necessary to fill the water to the edge of the aquarium; a level of 15 centimeters is sufficient. Sometimes crabs need to crawl out of the water, so place a rock at the bottom of the aquarium. Create a bank, recommended by Kenyan stones. You need to pour coarse soil onto the bottom of the aquarium, then it will siphon well.

Clean the aquarium regularly; the easiest way to do this is with a funnel. Install a filter in the tank so that the nitrate content does not go off scale. The rainbow crab loves to dig in the sand, so you can see holes with mounds in the aquarium. If you do not want such a mess inside the container, it is recommended to lay the pipe at an angle of forty-five degrees on the shore part; it should be larger in diameter than the size of the crab.

You can add a little salt to the water in a ratio of 6 ppm/1 liter, this will create a favorable atmosphere in the aquarium. For the soil, clean sand, not very fine, is suitable. The rainbow crab in the aquarium will feel good if the habitat is landscaped. To keep plants safe and sound, it is recommended to give animals foods rich in fiber and vitamins. Crabs need to hide; for the animal’s comfort, place underwater shelters in the aquarium.

The most favorite food of the rainbow crab is:

1. Brussels sprouts.
2. Pear.
3. Apple.
4. Boiled carrots.
5. Banana.
6. Orange.
7. Pumpkin.
8. Polka dots.
9. Shellfish.
10. Nettle.
11. Lettuce leaves.

The following types of plants can be planted:

It is better to diversify your pet's diet; homemade food is suitable: chicken liver, squid/mussels, potatoes, carrots, cabbage. Since indigo is a predator, give it bloodworms, mealworms, small insects, and snails.

The only plant that should not be given to crabs is celery. They don't like the taste of citrus fruits.

It is recommended to keep the temperature at 25 degrees. The acidity of the liquid should be 7.0 pH. For the best life of crabs, attach a filter and a low-power fluorescent lamp to the aquarium. For each animal, 0.3 sq.m. should be allocated. Swordtails, barbs and guppies can be housed with this type of crustacean. It has been established that crabs will not eat these fish.

Aquaterrarium and maintenance features

A simple aquaterrarium with everything you need to keep your crab.

The care and maintenance of rainbow crabs has its own characteristics. For a comfortable existence, the tricolor crab needs a large aquaterrarium. The average size for one animal is 50x40 cm. This beauty does not tolerate neighbors, so if you plan to keep several individuals, consider the area for each. In cramped conditions, battles for territory and food cannot be avoided. It happens that during battles pets injure each other and even kill each other.

In an aquaterrarium for a crab there should be 2 zones - a zone with water and land. A food-grade plastic container is suitable for a water container. Water is poured up to 15-16 cm. Under the soil for sushi they use: river sand, fine gravel, coconut shavings... When choosing an embankment, take into account the patriotic crab’s love for digging holes.

It is interesting to watch this worker when he, pressing several grains of sand, carries them to the water and pours them out. In this case, the entire bank will be dug up. You can lay a clay tube on dry land at a slight slope so that the crab can easily climb into it. This way he will have a hole and you will avoid disturbances. The sand grains of the soil should not be small, 3-5 mm per grain, this will make the soil easier to siphon.

You can put small stones and shells on land, and the crab will carry them from place to place. An aquaterrarium or aquas is the most optimal way to keep rainbow crabs.

A rainbow crab can also be kept in an aquarium. To do this, pour water up to 10-15 cm; stones and pieces of sushi should protrude from the water. The settler will spend most of his time on them - resting, warming up, eating...

You can add small fish to the crabs in such a container.

The crab can escape from the terrarium using filters, a thermometer and even rough edges in the corners. Therefore, you definitely need a tight, heavy lid that he won’t move away when he tries to escape.

If the indigo still manages to escape, place wet pieces of cloth on the floor and place bowls of water

. Most often, fugitives are found near them, and this can also save the life of your pet. Dry air is harmful to these creatures.

Fresh or salt water

The blue-red pet can live in fresh water. To do this, a filter with biological filtration must be installed in the water to purify the water from nitrates and nitrites, which are harmful to the animal. Every 5-7 days, a quarter of the water in the aquarium is replaced, this reduces the concentration of harmful substances. If the pool is a small container, the water is changed daily.

Water mineralization should be high, hardness (GH) greater than 10. Water acidity (PH) ―7.2-7.5.

After purchase, given that all the specimens sold were caught in the wild, to quickly adapt the animal, it is advisable to add sea salt to the water. Consumption: 1 tablespoon of salt per 5 liters of water. It should be free of flavors and additives. This salt is sold in pharmacies, supermarkets and pet stores.

Temperature

The most comfortable water temperature for crab will be 24-26°C, air temperature 27-29°C. When overheated, an indigo begins an extraordinary molt, during which it most often dies, since the body does not have time to prepare. Therefore, you need to monitor the temperature of the stones and the crab’s favorite places, adjusting the heating by moving the incandescent lamp.

Maintaining temperature control is vital for your pet.

If not properly cared for, the crab may lose limbs and claws.

Aquaterrarium decor

For decoration, use stones, driftwood, clay shelters, shell houses, stone grottoes, and slides. It is better to landscape with the help of artificial plants, since this swallow will definitely try to eat all living plants. If you still want to use live plants, check your pet’s taste preferences and offer him the plants you want to place on his territory. Perhaps some of them will not be to the taste of this gourmet. Then these plants can be used for landscaping.

Use your imagination when decorating your aquarium.

How does the molting process occur?

Information about how molting should occur is sparse. What is known is that “young animals” molt more often than mature individuals. Shedding is controlled by the animal's internal secretions. During molting, a new cover forms under the old shell. The whole process takes ten to thirty minutes, the old shell breaks between the chest and abdomen, due to which the animal is freed from it. During molting, a rainbow crab in an aquarium hides in algae and under stones to get better.

Attention! After molting, the crab should not be disturbed; you must wait three days.

Under good housing conditions, indigo will quickly recover after molting. Lack of calcium and low mineralization of water can lead to poor health of the animal and such an imbalance in the crab’s body will affect the color; red-blue-yellow stains may appear on the shell.

Lifestyle of the Kamchatka crab

The Kamchatka crab leads a fairly active lifestyle; it constantly migrates. But his path is always built along the same route. Travel speed is up to 1.8 km/h. Crabs walk forward or sideways. They do not know how to burrow into the ground.

In the photo there is a blue Kamchatka crab

During cold periods, the crab goes deep to the bottom, dropping to 200-270 meters. With the arrival of heat, it rises to the warm upper layers of water. Females and juveniles live in shallow water, while males move a little deeper, where there is more food.

Once a year, an adult Kamchatka crab molts, shedding its old shell. By the time the old cover disappears, a new, still soft, shell is already growing under it. The molting process takes about three days, during which the crab does not like to be seen and hides in holes and rock crevices. “Naked” females are guarded by males.

Molting for the “stronger sex” takes place later, around May, when the water temperature reaches 2-7 C⁰. In addition to the chitinous cover of the animal, the outer membranes of the heart, stomach, esophagus and tendons also change. Thus, the animal is almost completely renewed every year and gains new mass.

Young animals molt frequently - up to 12 times in the first year of life, 6-7 times in the second year and then only twice. After reaching the age of nine years, crabs become adults and molt only once a year, and old 13-year-old individuals only molt once every two years.

For what reason do they sometimes die in an aquarium?

Since the crab's body is covered in a hard shell, these animals can only grow during the molting period, before the fresh shell has time to petrify. Molting is a complex process for these animals; in nature it is controlled by hormones. During the molting period, it is necessary to create favorable conditions for the animal; food, temperature and lighting must be suitable. At this time, indigo should not feel deficient in vitamins.

Molting occurs in water, and not all owners provide decent maintenance. This is why rainbow crabs so often die when molting. Many people buy these colorful babies without realizing that this is a big responsibility. Natural conditions in an aquarium are quite difficult to create, so crabs do not survive more than one molt.

Keeping these extraordinary creatures is not easy; it is a lot of work that requires responsibility. It is noteworthy that during molting, not only the old shell is shed, but also some parts of the intestines. It's hard to imagine how it's possible to shed your own stomach, but these creatures do it.

Another reason for the death of rainbow crabs is incorrect temperature conditions, severe overheating or hypothermia. When overheating is strong enough, the animal begins to shed involuntarily, and the body does not have time to prepare for this process as it should. Therefore, you should not place stones close to a warm place where these creatures like to bask. If you touch the stone, it should not be too warm. If the stone is very hot, it must be lowered lower.

Food and taste preferences

Under natural conditions, the diet of the blue-red crab is dominated by plants. He enjoys eating insects and animals that have recently died.

• At home, his diet should include plant foods, greens: lettuce, cabbage (cauliflower, regular cabbage, Brussels sprouts), cucumber, apple, beets, boiled carrots, zucchini, asparagus, green peas.
• You should not give food with excess copper or starch - parsley, beans, potatoes, celery, vermicelli
  ... Fatty foods are contraindicated.
• Once a week, add protein food - lean veal, chicken or beef liver, shrimp with shell, fish fillet... Most animals eat dry food for fish or turtles, bloodworms, crickets, mealworms.
• The red and blue crab loves leaves from trees. They can even be prepared by drying them. Raspberry, oak, and maple leaves are suitable for this. You can give and harvest leaves of nettle, dandelion, clover, and calendula.
• Calcium should be a must in the diet. Small pieces of meat are rolled in ground eggshells, chalk is given for parrots, and calcium powder is given.

Video: rainbow crab eats an apple

Watching your pet, you will quickly pay attention to its taste preferences.

The tricolor crab feeds on land; food needs to be left in the same place. If you have several crabs, each should have its own feeding place, otherwise a fight cannot be avoided. Rainbow crabs cleverly hide food from their opponents under their abdomen, threatening with their claws.

You need to feed the rainbow crab twice a week, in small portions.

. Overeating is dangerous for indigos; it provokes frequent molting and bacterial diseases.

How does reproduction occur?

If we talk about the process of reproduction, then it is impossible to do it in captivity. Under natural conditions, reproduction occurs in seawater with the characteristics of the natural biotope. The life of a crab in an aquarium is an interesting spectacle; you can look at it every day and never tire of admiring it. Indigo is a reasonable creature, with the help of its high intelligence, these crabs recognize their owner and go into their arms. In general, whoever decides to purchase a rainbow crab for his aquarium will not regret it 100%. But at the same time, you need to understand that such a creature requires attention and special care, so you need to measure your strength so as not to ruin the crab.

Price and owner reviews

Nowadays you can buy many animals at the poultry market, including this handsome one. The cost is low, however, there is no need to take risks. We advise you to purchase it only in specialized stores. Exotics require proper pre-sale maintenance; in addition, they will advise you on how to handle them and help you choose food.

The price of a rainbow crab ranges from 850 to 1100 rubles, depending on the number of copies purchased. According to reviews from the owners, such a desirable acquisition is 100% justified. The animal not only pleases the eyes, but is also capable of displaying intelligence, gets used to the owner, and calmly goes into the hands. He is not picky about food.

It is interesting to watch for both adults and children; such proximity can brighten up a family evening. However, there is also a fly in the ointment. In addition to carefully fulfilling climatic conditions - temperature, filtration, cleaning - you will have to put up with some nonsense of character.

It is dangerous to put two males in one aquarium; you can lose either one or two at once. Only a heterosexual existence will be peaceful. And we repeat - do not forget about the lid for the aquarium, otherwise the nimble fugitive will disappear from sight.

The rainbow crab spends most of its time in its burrow, which is located on land.

Something with crab.

Something with crab.

Post by Rina163 » Jul 24, 2021, 03:54 pm

Something with crab.

Post by Roman » Jul 26, 2021, 11:42 am

Something with crab.

Post by Rina163 » July 26, 2021, 12:00

Something with crab.

Post by Roman » Jul 26, 2021, 12:54 pm

Something with crab.

Post by Rina163 » Jul 26, 2021, 01:52 pm

Something with crab.

Post by Rina163 » Jul 26, 2021, 01:52 pm

Something with crab.

Post by Rina163 » 08 Aug 2021, 08:56

Something with crab.

Post by Max » 08 Aug 2021, 09:10

Something with crab.

Post by Max » 08 Aug 2021, 09:14

Something with crab.

Post by Rina163 » 08 Aug 2021, 09:37

Something with crab.

Post by Rina163 » 08 Aug 2021, 09:52

Something with crab.

Post by Rina163 » 08 Aug 2021, 10:07

Something with crab.

Post by Max » 08 Aug 2021, 10:14

The appetite does not appear immediately, for me it takes 3-4 days. I can recommend sera rings for crabs and crustaceans, I also think that you should feed pieces of shrimp in the shell (be sure to remove what you haven’t eaten after 1-2 hours).

And the paws will become larger from moult to molt until they are restored.

White is incomprehensible, let's hope that the shell has not yet gained color.

And I would change the colored primer to a normal one. May be harmful.

Also, if the crab stopped eating, it means it was full, the food was removed so that the water did not spoil. They gave me a fresh portion every other day.

Something with crab.

Post by Rina163 » 08 Aug 2021, 10:26

Something with crab.

Post by Max » 08 Aug 2021, 12:32

I think you were asking why the crab has strange white spots. if you are confident in the excellent properties of the colored primer, then OK. But if you read more information on this topic, it is believed that they try not to put colored soil in jars, as there are precedents for the death of aquatic organisms.

Answer these questions: 1. What are my water parameters, are they acceptable for this species of crab? (What kind of water filtration and/or change system do I have? Is there any leftover food rotting in the soil (the crabs can hide it?) Is it enough to keep the crab alive?)

2. What is my water and air temperature, is it acceptable for this type of crab?

3. Do crabs need shelter? Do they exist?

4. Is there an excess or lack of nutrition, is it balanced?

5. Are there any substances harmful to aquatic organisms in the jar?

If all parameters are OK, then hurray!

90-95% of the problems of aquatic organisms are problems with water, the rest are diseases, and they develop due to a decrease in immunity in water that is unsuitable for this species.

But I want to please you, successful molting is a positive sign!

Conditions

When keeping a crab in an aquarium, it is important to know the characteristics of their body, daily routine, and dietary preferences. Before purchasing an arthropod pet, you need to weigh the pros and cons, find out information about keeping and caring for them.

A large number of varieties of crustaceans live in salt water bodies. Therefore, the water in the aquaterrarium should also be salted. To do this, use sea salt. If it is not available, then mix table salt, soda and calcium chloride.

Crabs do not need very high water levels like fish. 10–15 cm will be enough.

Water must be purified from foreign impurities, especially nitrates and ammonia. The inhabitants of the aquarium quickly become poisoned by the products of their vital activity. The water needs to be changed frequently and regularly.

Water hardness does not affect the life of arthropods, but this indicator should be below 10. Water acidity is 7–8 pH. The water temperature should remain at the same level of 25–27 degrees, without sudden fluctuations.

A soil base is essential in a pet's home. Bacteria multiply in the soil, useful for maintaining biobalance in the mini-ecosystem of the aquaterrarium. A good choice would be zeolite with the addition of crushed coral. Gravel and tuff granules are used as a replacement.

Their size should not be small; the correct size is 4–5 mm. This will facilitate the siphoning process, which is mandatory for crustacean soil.

Plants in an aquarium are planted not for decoration, but for food. Therefore, it is important to choose safe species of underwater plants. Plants that are aquatic or located in the water column are better suited. On rooted plants, crustaceans will dig up and damage the roots.

Suitable plants:

• Pemphigus.
• Duckweed.
• Java moss.
• Water hyacinth.
• Riccia floating.
• Vallisneria.

The main requirement for an aquarium is a sufficient amount of dry land. A fatal mistake would be to add crabs to a tank without dry land; because of this, the arthropods usually die within the first month after purchase. On land, lay a small slide or a ladder of stones that your pet can climb up.

The dimensions of the aquaterrarium for one representative are 50*50 cm, for several - 1*1 m.

When setting up an aquarium, remember the characteristics of crabs. They are more suited not to an open body of water, but to moist soil or moss under their limbs and high air humidity. But the aquarium still has a small bathing area in which the pet can completely immerse itself. The bath is useful during molting or simply to wet the gills.

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Avoid placing heating pads, filters, cleaners, or lamps with wires in the aquaterrarium. The arthropods will bite them with their claws and get electrocuted. Place all equipment out of reach.

To prevent burrowing, place a pipe inside that your pet can climb into.

Equipment

To monitor the temperature, you will need a thermometer. It is located on the wall or inside the aquaterrarium.

If the crab spends a long time in water, then install a filter and compressor in the pond. This will help purify the water and create small currents so that the water does not stagnate.

Freshwater

Freshwater crabs in an aquarium require settled fresh water with plenty of calcium carbonate. For an aquarium with fresh arthropods, the water temperature is maintained at 23 degrees. The water should not be too soft.

Appearance

Like all crabs, opilio has a protective shell. The carapace, that is, a continuous shield covering the soft parts of the body, is characterized by rounded shapes, its length and width are practically the same size. In an adult male it reaches 16 cm. The crab has long, up to 90 cm, flattened legs. They are located on the sides and lower part of the body. Females are approximately twice as modest in size. In total, the strigun has five pairs of limbs, four of which it uses for movement, and the fifth pair, equipped with claws, for obtaining food. There is a ridge above the mouth (called an epistome), which at first glance can be mistaken for teeth.

The shell is covered with tubercles and spines, has a gray-sandy or reddish color, and can turn green before molting. The crab's eyes are green. An adult male in the Sea of ​​Okhotsk can reach 2 kg of weight, in the Bering Sea it is slightly less - up to 1.4 kg.

How is king crab prepared?

Dishes containing crab meat are widely popular in different countries of the world. When preparing them, it is recommended to take into account some nuances:

• King crab, which is boiled alive, is considered the most delicious. Pre-frozen meat components will not be as tender.
• The meat component of king crab has a very delicate taste. This is why spices can quickly overwhelm it. You can highlight the exquisite aroma using celery, bay leaf, salt, apple cider vinegar and black pepper. Do not overdo it, it is recommended to use a moderate amount.
• The main feature during cooking is the elimination of the possibility of overcooking the Kamchatka crab. If you boil meat for a long period of time, it will definitely become rubbery. Cooking time must be calculated taking into account the weight of the Kamchatka crab. For the first 0.5 kg. 15 minutes is enough, and for the next 0.5 kg. - about ten minutes.
• When removing the crab from the pan, it is recommended to place it back down. This will eliminate the possibility of juice leaking. Once cooked, it will continue to absorb into the meat.

King crab can be eaten alone, in salads or as a topping for stuffing chicken. Meat goes optimally with mushrooms or Italian pasta.

Snow Crab Habitat

Strigun prefers muddy and sandy-muddy bottoms, cool, but not completely cold, water. In the Bering Sea, the crab lives at a depth of up to 115 cm and at temperatures around zero, in the Okhotsk Sea - at a depth of up to 166 cm. The younger the individual, the closer it stays to the surface. Sexually mature males and females prefer deeper places where they form large aggregations. During the breeding season, they rush down, and the movement of groups of crabs, stretching for many meters, looks simply mesmerizing.

Where does this crab live?

You can meet this very large animal in many seas. The main range is in areas located in the north and far east. The king crab often found in the depths of the Sea of ​​Japan, Okhotsk, Bering Sea, near the Shantar/Kuril Islands, etc.

In 1932, these animals were released into the Barents Sea, but only in 1974 were they able to catch the grown-up individuals. Now the population has grown greatly. The crab is often found near the coast of Norway, in the north of Spitsbergen, etc.

According to rough estimates, in 2006 there were about one hundred million individuals living in the Barents Sea. They prefer to live at different depths; the bottom can be either sandy or with a high content of silt.

The emergence and development of a new generation of Opilio

When the size of the carapace reaches 40-50 mm, we can say that the crab has reached sexual maturity. Full readiness to give birth to a male comes after the terminal molt, when the width of his carapace reaches at least 60 mm, maximum 120 mm. At the same time, the size of his claws changes, becoming much wider. The spawning period is spring, April and May. Before mating, swifts moult. One male can fertilize several females during one season. The reproductive potential of opilio is very high, this is explained by the fact that most of the larvae die, so you need to play it safe. One female produces about 150 thousand eggs.

Since industrial fishing only involves male crabs, there may not be enough of them to reproduce. But nature foresaw such a turn of events. The female can store sperm in a special part of her body and then use it. But usually there are enough males. About a week or two before mating, crabs of different sexes find each other, and the male firmly grabs his girlfriend’s legs with his claw. This is how he asserts his rights to her and protects her from encroachment. All the time that the claws are holding the female, the crab does not eat anything, and his lady moults. When the molting ends, the groom helps her get rid of the old shell, then fertilization occurs, after which the groom leaves his friend and rushes in search of a new one.

The female has a special place on her legs for eggs, where they settle to ripen. This is a long process, lasting from one to three years, after which the larvae finally hatch. The current carries them to their fate. Few will survive and grow to adulthood. The larvae stay on the surface, especially a lot of them accumulate in the gyres. So, in plankton, they exist for 3-5 months. In appearance, opelio larvae resemble shrimp.

The babies that win in natural selection turn into small rudimentary crabs - megalops. They descend to the bottom, where they feed on organo-mineral particles - detritus. This period lasts one month. At its end, the megalopa moults and turns into a full-fledged crab, which still has to grow. Having reached four years, opilio acquire all the features of a sexually mature individual. On average, swifts live 12-19 years.

Place in the animal world

Indeed, Cardisoma armatum spends most of its life on land. The distribution area of ​​this species is small - the coastal strip of some islands in the western part of the Pacific Ocean.

In sandy soil, the crab digs holes for itself, which serve as a refuge and place for rest. He spends most of his life near this shelter, searching for food.

If it is not nearby, then the multi-colored arthropod cheerfully goes in search of food in the nearest thickets. You can be sure: there he will definitely find something to feed himself.

An interesting feature: the crab always returns to its hole. How he finds her is unclear.

But sometimes incidents occur when, having returned to his sandy house, the “traveler” finds it occupied by another representative of the species. In fact, why would an invader dig a hole for himself if he finds a ready-made one?

In this case, a showdown inevitably begins, and victory does not always go to the true owner of the house. Well, in this case, our rainbow crab will move away and deftly dig a new house for itself. Even better than before!

But this animal rarely enters brackish ocean water. This only happens during the mating season and during molting. However, it also feels great in fresh water, which has allowed some scientists to consider the rainbow crab not only land, but also freshwater.

Sexual characteristics are weakly expressed, but experts determine gender by the appearance of the abdomen - the back of the abdomen. If in males it is narrow, then in females it is much wider and resembles a blunt triangle in shape. In addition, females are often larger than males.

Nutrition and lifestyle

Snow crab feeds mainly on small marine life. It is omnivorous and its diet changes with age. As already mentioned, larvae feed on plankton, megalopas feed on detritus. Young animals prefer to consume worms, and adults have a wide choice - their diet includes mollusks, cephalopods, shrimp, starfish, urchins and other representatives of marine fauna, as well as bryozoans, sponges, and algae. The larger the size of opilio, the more space mollusks occupy in their diet. Intraspecific cannibalism is also observed among crabs, with larger individuals devouring smaller ones.

It is interesting that for a couple of weeks before and after molting, the snowtail does not eat anything. Molting is necessary so that the crab can grow and acquire a larger shell. When the old shell cracks and falls away from the body, a new, but still soft, one is revealed underneath. Until it absorbs calcium salts and hardens, the strigun hides in a secluded place. In order for the new coating to be of sufficient size, taking into account the growth of the crab until the next molt, the animal absorbs water and increases in volume by one and a half times. After the shell hardens, the crab gets rid of excess water and regains its natural parameters. But at the same time, the size of the shell “with a reserve” gives it the opportunity to grow.

Molting during the burial of a hermit crab

Crabs buried in their bedding are a little more difficult to care for or determine whether they are molting or not. Smooth the sand around their hiding place and look for tracks to see if they are coming for food at night. Many crabs often disappear during the day, but tracks around the cage in the morning will let you know they are still active. If weeks have passed since your crab burrowed and you are still unsure whether your hermit crab is alive, you can carefully sweep some sand around its hiding place to check for any rotting smell.

Commercial significance and nutritional characteristics of snow crab

In Russia, opilio is mined in Primorye and the Far East. In order to preserve the species, there is a rule to hunt only adult males with a shell diameter of more than 15 cm, and then only during a certain period of time (from October to April) and according to a quota. Mining takes place at a depth of up to half a kilometer. Thanks to the measures taken, at the moment the number of swifts does not have a tendency to dangerously decrease.

Crabs are harvested for their nutritious, tasty meat. It has a salty-sweet taste, contains a lot of protein and virtually no fat. This meat is dietary and delicious; dishes made from it are served in the best restaurants in the world. It is also sold in stores and markets, so anyone can prepare opilio at home. The composition of the meat is rich in B vitamins, it contains many useful microelements, such as potassium, phosphorus, calcium, iron, etc. At the same time, the calorie content is low, 100 grams of meat accounts for 73 kilocalories, so those who adhere to a diet can safely consume this product.

The easiest way to prepare it is boiling, but baking is also possible. Snow crab meat complements various salads well, giving them a unique piquant taste, and can also be consumed as a main dish.

A resident of Kamchatka coastal waters, the snow crab is an interesting representative of marine fauna that is of great commercial importance.

Dangers

The main danger to Kamchatka crabs is, of course, the people who catch them commercially. In addition, human activity affects the ecology and pollutes the ocean, the habitat of this animal. All this leads to a decrease in the population, so people are trying to help replenish it. Periods of predatory extermination must become a thing of the past. Nowadays, permissible production volumes are determined every year, taking into account the number of livestock. Only adult males can be harvested.

An adult crab has few other enemies. Its durable shell, also armed with spikes, serves as a good shield. Young animals are less safe. Young crabs can fall victim to internal cannibalism, when larger individuals attack smaller ones. Predatory fish, sea otters, and octopuses also pose a danger. Now the most favorable habitat for the Kamchatka crab has become the Barents Sea, where this species was artificially populated during Soviet times. This resettlement was planned back in 1932, but was implemented only in the 60s after several unsuccessful attempts.