Fish and other aquatic creatures

Hermit crab or hermit crab: description


The hermit crab is one of the representatives of the crustacean class. In nature, they are many species that can live both on land and on the seabed.

The hermit crab is a fairly common species, one of those animals that can always be found on the seabed. Its size depends on the species, but on average it does not exceed 8-12 centimeters.

The peculiarity of this type of crayfish is its soft abdomen, on which there is no shell. This makes hermit crab vulnerable enough, therefore, in order to protect itself, the animal is forced to hide all its life in the shell of the gastropod. Animals almost never part with their house, everywhere they wear it on themselves. In order to keep the sink, the back pair of hermit crab paws shortened in the process of evolution.

Some types of crayfish leave the shell and go to dry land after they have grown a little. However, their abdomen is still vulnerable, so the animals have to constantly bend their tails under them.

Seeing a hermit crab hiding in its shell is quite fascinating. Only his head and three front pairs of legs are visible. It is important to note here that the left claw of the front pair of paws of the cancer is always larger than the right. This is another precaution. It is the left claw of the hermit crab closes the entrance to his house.

The color of crayfish differs not only depending on the species, but also on its age. So, young individuals almost always have a pale beige color. Growing up, they become blue, pink, purple, red, or other shades of these colors.

Housing problem

The shell, which serves the hermit crab as protection and home, at the same time presents many problems. The fact is that as the individual grows, she has to change one house to another one that is suitable in size. In this regard, the sea hermit crab is much more fortunate than its land relatives, because there are almost always empty shells on the seabed.

In the absence of an empty shell, the crab is able to modernize its old home. How he does it? With the help of the same pair of legs that hold the house, it expands the inner space of the shell, and causes chemical corrosion of its walls. This behavior is more characteristic of land species, for example, Ecuadorian hermit crabs. Besides the fact that the house can be used for a longer time, such a redevelopment has another significant advantage. The weight of the shell becomes smaller, so it is much easier to carry it with you. It should be noted that the thinning of the walls does not affect the protective function.

For the crayfish living on the seabed, the housing problem is solved relatively easily: they simply transplant into another sink. If this is absent, the cancer begins to look intently at their relatives. If the hermit is lucky to find a brother, whose shell is clearly large for him, he can offer an exchange. For this cancer in a special way taps on the sink. If a neighbor agrees, he responds by knocking rock on a claw. But it may be that he does not like this idea. In that case he

takes a threatening posture, or simply closes in his house.

Hermit crab and sea anemone

Most often, the hermit crab can be seen not alone, but with a cohabitant. It is actinia. This is one of the classic forms of symbiosis, when both animals benefit from coexistence. For cancer, this is an additional defense, because actinia gives off a special poison that is dangerous for enemies. It should be said that the constant spraying of such a poison produces immunity in a hermit crab, so it does not cause him any harm.

For anemone, such cohabitation is a way to get more food, because the cancer is constantly moving, and it can catch more territory.

It is worth saying that almost all adult sea anemones live on the shell of a hermit crab, or directly on its back. Only young individuals remain on the stones. But many cancers independently transplant them to their house. In addition, when the cancer moves to another house, he carefully relocates his cohabitant.

There are cases when two sea anemones can live simultaneously on the shell. In this case, they are arranged in such a way as to balance the house, and do not accidentally turn it over with the owner.

Other roommates

Hermit crab and sea anemone are not the only neighbors. On the shell of cancer can live other animals. For example, polychaeta worms can live with them. Although these animals are food for the cancer itself, research has proven that it does not touch its "own" worm. They take food together, as the worm picks up its remnants during the host meal. In addition, polychaetes perform the functions of orderlies. They cleanse both the shell itself and the belly of the cancer from all kinds of parasites.

Among intestinal cavities, anemones are also not the only female partners who are recruited by hermit crab. The photos taken by scientists prove that zoantaria can settle on the hermit's shell. In this symbiosis, their role is exactly the same as that of actinium.

Hermit crab - content in an aquarium.

Scientific name: Clibanarius spp.

Other names: Dwarf hermit crab (born Dwarf Tip Hermit Crab).

The level of care for hermit crab: easy. Well suited for marine novices, but before launching into an aquarium, cancer must necessarily undergo a slow drip acclimatization (an hour or longer) in order to get used to the parameters of aquarium water. Do not be alarmed if you notice that a hermit crab began to molt.

Hermit crabs live: 2-4 years, but may be longer.

Size: up to 3 cm (1 inch).

PH level: 8,1-8,4.

t 0: 22-27 0 С (72-80 0 F).

Specific gravity: 1,022-1,025.

Clibanarius habitats: tropical and subtropical ocean waters.

The temperament of hermit crabs / behavior: very peaceful.

Reproduction of hermit crabs: hard-bred.

Aquarium size: 50l for one individual.

Compatibility of hermit crabs: despite the fact that they have a protective shell, care should be taken if you plan to keep them with more aggressive marine invertebrates.

Diet / Food for hermit crab: they, as a rule, rummage in live stones and sand, searching for algae and cyanobacteria (brown-red algae). If there is not enough algae in the aquarium, feed them with vegetable food, for example, dried algae.

Region: mainly located on or around living stones.

Floor: There are no definite ways to distinguish a male from a female.

Cost: you can buy a hermit crab for $ 8-15.

Interesting on YouTube:

Description of the land hermit crab

Seven species of tropical hermit crabs are distinguished. These crabs in length reach about 3 centimeters, the weight of an adult individual reaches 110 grams.

Body shape is cylindrical, elongated. The body is covered with small hairs. The front of the body is protected by a hard shell, and the abdominal part is much softer.

Land hermit crabs have 5 pairs of legs. The first pair is a claw. With the help of the right claw, the crab eats, and the left one is used for protection, for example, it can close the entrance to the hole during the danger. Most crabs have purple claws, but they are also lemon, brown or red. The second and third pair of crab legs is meant for walking. The last two pairs of legs are very small, they sometimes do not protrude from the shell.

Caribbean crabs breathe with the help of gills. There are 2 pairs of retractable antennae: long antennae are used for touch, and short ones perform the function of smell. The vision of land hermit crabs is good.

Semi-arched hermit crab (Coenobita clypeatus).

When the crab is outside the shell, its sex can be determined: the male has hair on the last pair of legs, and there are no appendages on the abdominal cavity.

Lifestyle of hermit crabs

Wood crabs are social animals living in numerous groups. They are nocturnal, their peak of activity is observed at 20 o'clock. Hermit crabs do not like heat and the sun, so they hide in small holes in the daytime, under stones, logs, leaves, and the like.

These crabs are constantly hiding somewhere under logs, pebbles or branches.

Land hermit crabs live on the sandy shores of the Caribbean islands, at a distance of 1.8-3.5 kilometers from the water. They are found among coastal plants. They avoid swamps and areas of dense vegetation. Hermit crabs prefer low salinity water.

If a tropical land crab stays in the water for a long time, it will drown. Adults molt every 12–18 months, and young molt several times a year. After molting, the crab chooses a new, larger shell.

At temperatures below 20 degrees, the activity of land hermit crabs decreases, and at temperatures below 18 degrees, they hibernate. These crabs can make different sounds: chirping, cracking, croaking.

Tropical land crabs hermit feed at night. They are omnivorous scavengers. Also in their diet includes the fruits of cacti and even fresh litter of horses and cows. In captivity, their lifespan can reach 11 years.

Land hermit crabs hibernate.

Reproduction of land hermit crabs

The breeding season for wood crabs falls in August-October. To mate, males and females have to leave their shells. Young females lay 800-1200 eggs, and adult females - 40-50000 eggs. The color of the newly laid eggs is red-brown, within a month they turn blue or gray.

After 3 weeks after mating, the female goes to the shallow water, her eggs are on the 5th leg, she collects them and shifts them to wet stones. Eggs are washed away by waves in water.

In the larvae of land hermit crabs there are several stages of development: Zoe, then Glaukotoe, after the young crab. During the metamorphosis, the larva sinks to the bottom, and then creeps to the land.

In the process of development, crabs go through several stages.

Zoe is thin and long, its size reaches 3 millimeters. She has 2 large eyes. At this stage, the larva feeds on plankton. Zoe makes 3-4 molts, during which grows.

After 4-5 molts, the larva enters the glaukotoe stage. At this stage, she has very small antennae, her eyes are located on the stalks, and the first paws are transformed into claws. Glaukotoe looks like an adult crab. This stage lasts about a month, after which the larva grows to 5 millimeters.

Before the last stage, young crabs begin to look for the shell. If a crab leaves the sea without a shell, it usually dies.

On land, young crabs are active mostly at night, and during the day they hide in various cracks and crevices.

Recommendations for the content of hermit crabs

These crabs are kept in terrariums of the horizontal type. The soil is partially flooded with water, but the water level should be very low, since the hermit crabs easily sink.

Puberty in wood crabs begins in the 2nd year of life.

There must be a sufficient number of shell-houses in the terrarium so that the crab can find a suitable size for itself after regular molting. In addition, it is recommended to place pieces of wood, corals, branches and artificial plants.

The substrate is washed sand, coconut chips, and small gravel. Substrate should be washed as it gets dirty. You can keep wood crabs in groups, so they will even be more fun. Crabs should swim weekly. The temperature in the terrarium is maintained at 23-28 degrees, and the humidity in the region of 50-70%.

It is very simple to feed land hermit crabs as they are omnivorous, it is easiest to use specialized feed for fish.

The origin of the crab and its native habitats

Perhaps someone may ask: "Why is he a hermit?". And, indeed, where did this strange name of this living thing come from? There are many different stories, legends and scientific versions to this question. One of these is the version of the relationship of this crab and the rest of the inhabitants of the deep sea.

Once upon a time, an unknown creature, whose body was equipped with several claws, approached the seashore a long time ago. Naturally, such a miracle of nature aroused the interest of the inhabitants of the sea and when they decided to get acquainted with this stranger, he began to talk about himself as an outstanding soldier who could not be defeated. For a long time he convinced everyone that he was the bravest, handsome and strong. And if at first many of them had such thoughts that he was no longer a brave and daredevil, but simply a boaster, but soon everyone unanimously accepted this information as a tribute, since neither dolphins nor fish and jellyfish have such powerful and big claws. Since then, everyone began to worship and submit in every way to an amazing animal, many even bribed him with a wide variety of delicacies.

But, unfortunately, such power and popularity did not last long, soon a flock of birds of prey decided to settle in the sea kingdom, which completely did not please its legitimate inhabitants, in their turn they hurried to ask for help from the great and terrible crab. banished unwanted guests. Here and everyone learned the truth. It turned out that the crab does not possess any supernatural power, moreover, he is still a coward, no one, of course, expected such a turn of events, and everyone drove away their ruler. And since then he has led a solitary and recluse lifestyle, trying to simply not be seen by anyone. From here and such interesting name.

The second version is not so exciting, but still more realistic. The thing is that the crab must always be hidden in its shell, which is often the empty shell of mollusks, because without it it will become very easy prey for many of the most diverse who want to eat them.

For the first time the world heard about an unusual crab, which lives far from water bodies in the far 1802 from the scientist Lathreil. It was this scientist who classified this original representative of the world fauna into a class of higher crayfish, a type of arthropod, a squad of decapod crayfish, and a subfamily of hermit crabs.

With their Homeland, these living decapods worship the lands around the Caribbean Sea, Venezuela, the Bahamas, Belize, India, Florida, the Virgin Islands, and many other countries. This eccentric settles in an area that is located over 500 m above sea level, feels excellent on sandy shores away from water, and sometimes it can move several kilometers away from water bodies. He likes very much the various plants on which he happily climbs, for example, low trees or mangroves, but the cute hermit tries to avoid dense dense vegetation and swampy locations. Maybe afraid of getting lost or drowning right in the thickness of the marshes?

Peculiarities of the behavior of the crab in its natural habitat

Despite their names, these land arthropods do not tolerate loneliness, so they try to live in the territory they occupy by social groups of small numbers. But since this little cow doesn’t like much to be seen by anyone, its activity begins in the evening and continues until the sun rises. In the daytime, this amazing creature prefers to hide in various earthen minks and other depressions, in the crevices of stones, and under stony debris, in the rhizomes of trees, or simply carefully wrapped in fallen leaves where it is unlikely to be noticed. Most of all in his life, he does not like the heat and direct scorching sunlight, it is also one of the reasons why the crabs are hiding during the day.

The optimum air temperature for this land dweller is 23–26 degrees, if it gets cooler outside, the activity of hermit crabs significantly decreases, and in the case when the thermometer falls below 17–18 degrees, the arthropod simply hibernates.

The diet of these decapod crayfish is not just diverse, they are simply omnivorous, their menu can contain absolutely any product from the plants and fruits of the cactus to cow and horse droppings, the main thing is that it should be fresh, so they don’t have much to eat problems.

The continuation of the hermit crab

The height of the mating season in such crayfish begins from the last days of summer and lasts until mid-autumn. No matter how hard the crabs try to wrap themselves in their shells, they will have to leave for the time of mating. Количество отложенной икры сильно зависит от возраста самки, так молодая особь женского пола, которая только недавно стала половозрелой, может отложить от 800 до 1500 икринок, а вот взрослые самки, которые уже становились матерями, откладывают обычно 30 000 — 50 000 икринок. У отложенных самками-крабами яиц есть необычное свойство — на протяжении инкубационного периода они могут изменять свой окрас, так только что отложенные яйца оттенены коричневым колером с легким красноватым отливом, а спустя примерно 20–30 дней они преображаются и становятся серыми, а иногда даже синими.

Approximately 2-3 weeks after the mating process, the expectant mother gradually approaches the reservoir, carefully storing the eggs, which are located in her leg, upon arrival to the water, she carefully collects them and lays them on the pebbles, which are washed by the water, and the eggs leave in water column.

According to many scientific sources, this species of crabs has three stages of development of the larvae - these are zoe, glaucotoe and young crab. All the above-mentioned metamorphoses occur at the bottom of the reservoirs, and then they float to the surface of the water and go to the shore.

Characteristics of the appearance of the hermit crab

After reading a lot of stories about this "predator" you might think that this should be a creature the size of a dolphin at least, but no. This is quite a miniature creation, the length of which does not exceed 30–40 mm, and the body weight of an adult held male varies from 90 to 120 grams.

The body of this mini-cancer in its configuration resembles the correct cylinder, so it is slightly elongated and slightly rounded. The entire surface of the calf is covered with small hairs. On the front side of the body there is a kind of shell, it is rather rigid in its structure and slightly protects its owner from injuries and bruises, but the abdomen area is completely devoid of such armor and at the slightest junction with something sharp or predatory, is damaged.

Nature has bestowed on these representatives of the animal kingdom great wealth in the form of ten limbs. The first pair of paws is represented by powerful claws, with the help of which the crab eats and defends itself, it is of course not able to hurt someone with it, but here it can cover the entrance to the mink or to any other shelter. Pincers can be painted in a wide variety of colors and shades, from lemon yellow to purple.

The second and third pair of legs of this arthropod performs its direct purpose, namely, with their help, the animal moves. Why does he need the last two pairs - nobody knows for sure, maybe in reserve? Simply, they are very tiny and almost never leave the sink.

As a respiratory organ, nature gave him a gill. Also, a hermit crab boasts two pairs of antennae that can be extended, they are quite useful, some of them, longer ones, perform the function of touch, and those that are shorter than the smell. Also, these crustaceans can boast excellent vision.

Sexual dimorphism is well expressed, but it is possible to notice it only when this crank is outside the shell, and this happens very rarely. Representatives of the stronger sex are devoid of appendages in the projection of the abdominal cavity, and the last pair of limbs is covered with hairs.

Rules for keeping a hermit crab in an aquarium

It is half the battle to buy a hermit crab, it is also important to create living conditions for him in which he will feel at home and even better, because at home they will feed him regularly, he will not need to constantly hide and hide, as there is no danger he is not afraid.

Before you bring such a wonderful wonder of nature into your home, you should arrange for it its own roof over your head. As a personal crab dwelling, a more or less spacious terrarium of a horizontal type will be perfect, some call it a crabarium, but this does not change the essence of the container at all. It is imperative to cover the floor surface with some kind of substrate, as a last resort it is good to use coarse sand, river pebbles, coral sand and even compressed coconut fibers. As for the width of the soil layer, it will be good that it gradually decreases, that is, in one of the corners of the terrarium you pour a little more soil, the thickness of this layer should be at least 10–12 cm, and the width to the opposite angle can reach about 4 –5 cm

By nature, the hermit crab is a very neat creature, so it will not require daily general cleaning, but it is still not recommended to forget about them. The dwelling itself should be cleaned approximately once every two weeks, it is necessary to clean the substrate somewhere once a month, but you can completely replace it once every 4-6 months, it all depends on how many individuals you have in one crabs.

Do not forget that this unique pet is very sensitive to temperature extremes, therefore for a comfortable life without a thermostat is nowhere. The average temperature of the air in the crab abode should be from 22 to 25 degrees. To maintain it at this level, you need to purchase some kind of heating device, it is best to use a thermal matrix, which is placed directly in the substrate.

Air humidity is also an equally important condition not only for the comfort and coziness of your home crab, but also for its health. The humidity coefficient should not be lower than 50%; with excessively dry air, your pretty pupil may experience serious problems with the organs of the respiratory system.

Since, by nature, a hermit crab is usually a night resident, no additional lighting equipment will be required, even if he changes his work regime in captivity, but at night he will sleep peacefully and peacefully. But if the wakefulness period of your new friend falls at night, then he may bring some anxiety. Since these craftsmen also make various sounds, such as croaking, low whistling, crackling and even chirping, but due to their small dimensions, it can only disturb your sleep if your bed is right next to his house.

Do not forget that, like all Crab pets, you need to put your energy somewhere, although it is small, it is still there. In order for this tenant to have something to do in his terrarium, you can put branches of trees, various snags, it is recommended to make peculiar ladders or bridges, your friend will climb on them.

Like a cat or dog, your home hermit with claws needs attention, be sure to tame this exotic, he also needs to feel that he is not a lonely crab at all. To do this, offer him goodies from the hands, and also it should be bathed every week, those individuals who are already accustomed to human hands are not at all afraid of this procedure.

The diet of the homemade tenth crustacean can be quite diverse, since he was accustomed from birth to eat everything that catches his eye. The most favorite food for land crab are fruits, namely bananas, apples, peaches, pears. In addition, he will never give up corn, almonds, peas, crackers and even dry dog ​​food. Usually, this omnivorous pet is able to “devour” as much as 5-10 grams of food at one meal. You can also feed your crustacean with normal dry fish food. Leftovers are best removed immediately after the meal.

From time to time it is necessary to feed this fragile comrade with vitamin and mineral complexes, especially calcium, which is vital for good development and good health in general.

Purchase and price of a hermit crab

Today, you can buy, probably, anyone from the animal kingdom, there would be a desire and enough material resources, a hermit crab is no exception, and even to buy it you will not need a large fortune. The average price starts from 400 rubles.

See below for more information about hermit crabs:


Due to the evolutionary development, the hermit crab has received many adaptations that allow him to feel comfortably in the ocean. For example, his hind legs were shortened to make it easier for an animal to move with a heavy house on its back. At the same time, the front part of the body of these crustaceans is securely covered with an impressive layer of chitin, but the abdomen is soft and devoid of any cover. The size of the animal usually does not exceed 1 inch, i.e. 2.5-3 centimeters.

Interestingly, the question of how a hermit crab looks like cannot be answered unambiguously. The fact is that to protect the abdomen, he uses a variety of objects. The classic version of the house is a clam shell, in which the animal hides during an attack or a hunt.

As the cancer grows, sometimes it has to change the shell to a larger one. Most often, he prefers something light, because such a house is not so difficult to move from place to place. Scientists say that sometimes a kind of shell exchange takes place between hermits! One of them taps on the shelter of the other, offering a deal. If the second does not agree to it, then simply closes the entrance to its sink with a claw.

If there are no mollusks nearby, then instead of seashells, the hermits can use any objects suitable for protection. This may be, for example, a piece of bamboo stem or any other solid object that reliably protects the tender body of the animal.


A hermit crab is found in the following bodies of water:

  • Baltic Sea,
  • North Sea,
  • European coast,
  • Mediterranean Sea,
  • coast of the islands of the Caribbean.

Usually these animals live in shallow water, although some species prefer to descend 70-90 meters under water.

What are hermits

An incredibly large number of hermit crabs lives in the seas and oceans. Outwardly, they are quite similar and differ most often only in color. The table below shows the names of the most common of these animals:

Russian name Scientific name English name

Steppe hermit crab Clibanarius sp. Tawny hermit crab

Hermit Crab Clibanarius cruentatus Gold-spotted hermit crab

Mexican red legged hermit crab Clibanarius spp. Mexican red leg hermit crab

Orange-striped hermit crab Clibanarius infraspinatus Orange-striped hermit crab)

Blue-striped hermit crab Clibanarius longitarsus Blue-striped hermit crab

What does a hermit crab eat

The next step when meeting a hermit crab is a description of its diet. Like his relatives, he belongs to omnivores, i.e. Eats elements of plant and animal food. Among his favorite products include:

  • worms
  • seaweed,
  • spawn of different types of fish
  • mollusks,
  • fish

In some cases, hermits may also eat carrion or food remnants of neighboring anemones. If these crayfish come on land, they can sometimes eat coconuts, fruit, or small insects.

Life in an aquarium

A hermit crab in an aquarium is an ideal choice for beginners. Caring for him is a no-brainer. It is important to remember that these animals need to be acclimatized. It is necessary to produce it slowly, within 60 minutes or more, so that the pet has had time to get used to the quality of aquarium water. Also, do not worry if you suddenly notice that the animal sheds, this may be due to a change in habitat.

It is recommended to keep a pet in sufficient volume of water (about 50 liters for one individual). Recommended temperature indicators - 22-27 ° C, and the pH level - 8.1-8.4. Feed hermits can be dried algae, but often they can take care of themselves, finding food in the sand and live rock. These crayfish eat brown algae, also called cyanobacteria.

These marine animals are not recommended to settle near the aggressive inhabitants of the aquarium. Although hermits have protection, they can fall victim to attacks, such as some invertebrates. At the same time, the crayfish themselves are very peaceful and kind, so they will never harm the neighbors in the aquarium.

So, the content of a hermit's cancer is a fairly simple and busy affair. Visit such an unusual pet in your tank and watch his life and behavior.