Why is the hermit crab? Cancer hermit. Lifestyle and habitat of the hermit crab. Some types of hermit crabs

The hermit crab is a prominent representative of the crustacean class. They have many species, each with its own little characteristics, but for the most part they are similar to each other.

Description of the hermit crab

The hermit crab lives almost its entire life in the shell of a gastropod, although in rare cases they can choose another shell, the main condition is that it is quite spacious and comfortable. Life in the house is due to its relative vulnerability. So, outwardly it is covered with a hard chitinous shell. But its abdomen is practically unprotected by anything, and therefore, in order to protect itself from predators, they hide their entire body in the shell.

It is also important to note that there are species that, after growing up, leave their shells and move onto land. To protect their vulnerable belly, they tuck their tail completely under them. The sizes of these crayfish are quite varied, some are as small as a fingernail, and some are as big as a fist. As they grow, they change shells during molting. At the same time, always selecting a new house both in size and weight, so that it is not difficult to carry it with you.

Only the head and three pairs of legs protrude from the shell. The left claw of the first pair of paws is always larger than the right one. It is with this that he closes the entrance to the shell when he hides. The remaining legs are used for quick movement and securing in the mobile home.

The color depends on the species and age of the individual. There are blue, purple, red, pink with different shades. Juveniles are almost always pale beige in color. The hermit's eyes are oblong in shape. As additional protection, they may place sea anemones on their claws or shell. At the same time, anyone who wants to take the sink or climb into it can at least get burns.

Habitat and food

Hermit crabs live on the shores of Australia, Indonesia, the Marshall Islands, Malaysia and so on. Various species are found almost all over the world from the Indian to the Pacific Ocean. They live in shallow waters of seas and oceans. The greatest depth at which they occur is 80 meters. Some species live on shores or in forests located directly next to the ocean.

Nutrition varies depending on habitat. Land hermits feed on spoiled fruits, fallen coconuts, and small insects. Marine species are primarily predators and their frequent food is annelids, dead fish, and shellfish.

Reproduction and features

Free by nature and habits, hermit crabs do not reproduce in captivity. Therefore, for the purpose of reproduction, you always have to buy a female with eggs. They reach puberty in the second year of life. At this time they are already sufficiently formed. Almost all species reproduce in water, so that even after leaving the marine environment, they have to return for breeding time. They live for about 11 years. Sometimes more or less depending on habitat and nutrition. Aquarium lovers often choose this particular type of crayfish as a pet. Although they do not breed in captivity, they are quite easy to care for.

Class - Higher crayfish
Order - Decapods
Superfamily - Hermit crabs

Of all the representatives of the fauna of our planet, crustaceans are perhaps the most common. This biological subclass includes about 73 thousand representatives. They live in various bodies of water, both salty (oceans and seas) and freshwater (lakes and rivers). The latter also include the most famous types of crayfish, for example, the hermit crab, which is what we will talk about in our article today. We will try to give a detailed description of this species and talk about the intricacies of keeping it at home.

Appearance

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

It is interesting that the question of what a hermit crab looks like cannot be answered unambiguously. The fact is that he uses a variety of objects to protect his abdomen. The classic version of the house is the shell of a sea mollusk, into which the animal hides during an attack or hunt.

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

If there are no shellfish nearby, then instead of shells, hermits can use any objects suitable for protection. This could be, for example, a piece of bamboo stem or any other hard object that reliably protects the delicate body of the animal.

Habitat

The sea hermit crab is found in the following bodies of water:

Baltic Sea;
North Sea;
coast of Europe;
Mediterranean Sea;
coast of the Caribbean islands.

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

What are hermits like?

An incredibly large number of species of hermit crabs live in the seas and oceans. Outwardly, they are quite similar and most often differ 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

Gold-spotted hermit crab Clibanarius cruentatus Gold-spotted hermit crab

Mexican red leg 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 getting to know a hermit crab is to describe its diet. Like its relatives, it is an omnivore, i.e. eats elements of plant and animal food. Some of his favorite products include:

worms;
seaweed;
caviar of different types of fish;
shellfish;
fish.

In some cases, hermits may also eat carrion or food remains of neighboring sea anemones. If these crayfish come to land, they can sometimes eat coconuts, fruits or small insects.

Reproduction

The main role in reproduction belongs to females. The female’s body regularly produces eggs (sometimes up to 15 thousand at a time!), which she carries on her abdomen. After a week, larvae emerge from them, ready to swim and live in water. They molt four times and become young crayfish.

In living nature, the process of reproduction does not stop throughout the year. Hermits do not reproduce under artificial conditions. At the same time, cancer lives for a maximum of about 10-11 years.

Life in an aquarium

Hermit crabs in an aquarium are an ideal choice for beginners. Caring for it is a simple matter. It is important to remember that these animals definitely need drip acclimatization. It is worth doing it slowly, over 60 minutes or more, so that the pet has time to get used to the quality of the aquarium water. Also, do not worry if you suddenly notice that the animal is molting, this may be due to a change in habitat.

It is recommended to keep your pet in a sufficient volume of water (about 50 liters for one individual). Recommended temperatures are 22-27°C and pH levels are 8.1-8.4. You can feed hermits dried seaweed, but they can often fend for themselves by searching for food in sand and live rocks. These crayfish eat brown algae, also called cyanobacteria.

It is not recommended to house these marine animals next to aggressive inhabitants of the aquarium. Although hermits have defenses, they can be attacked by, for example, some invertebrates. At the same time, the crayfish themselves are very peaceful and kind, so they will never harm their neighbors in the aquarium.

Did you like the article? Take it to your wall and support the project! Hermits are permanent wanderers of shallow sea waters. So, with a house on their back, they waddle along the sand and stones in search of food: organic remains and small algae. If you see a quickly moving mollusk shell, rest assured that it has been occupied by a hermit crab as its home. Only legs and a bouquet of sensory organs stick out from the house - compound eyes on stalks, the first and second pair of antennas. These feathery fans are the organs of touch and smell, and at their base there is also an organ of balance. Hermits live in the shells of gibbula, nassa, cerithium, and rapana. It has been noticed that individuals in rapana shells reach larger sizes. Young hermits occupy the shells of rissoi and tricolia.

Having no shell covering, hermits with a bare and rather plump abdomen are a constant temptation for numerous predators. Therefore, the hermit crab hides its precious abdomen: it selects an empty shell of a gastropod and, backing away, climbs into it. Although the abdomen and this shell were not at all created for each other by nature, it adapts well to the position of the lodger in its spiral tunnel. The claws of a hermit crab are also, as a rule, disproportionate, and when it wants to completely protect itself from any danger, it climbs deeper into the shell and blocks the entrance with the larger claw. “It is impossible to get a hermit out of her shell, since he breaks into pieces and never leaves his refuge, unless it becomes cramped for him and it becomes necessary to find another, more spacious shell for his room,” wrote Alfred Bram.

This exchange of living space is perhaps the most interesting thing in the hermits’ lifestyle. These crabs grow throughout their lives, so the housing problem worries them almost constantly. It’s good if there are a lot of empty shells at the bottom, but this is not always the case (hermits never attack living snails or try to free the apartment by force). If the choice of available housing is small, the hermit looks closely at his brothers. If he finds someone whose shell is too big, he offers an exchange. This is done by special tapping on the shell. If the partner agrees, he responds by lightly tapping the initiator of the exchange on the claw and leaving the shell. If he doesn’t want to, he hides deeper or takes a threatening pose. The signal knock on the shell is different for each type of crab. If the exchange takes place, both partners can benefit. One needs to expand his living space for growth, while another doesn’t make much sense in carrying around a house that is too heavy and spacious. There is an area off the coast of Florida where three species of hermit crabs live together. While observing them, biologists discovered that two of them did not understand each other's language. Representatives of the same species, in order to propose an exchange, tap their shell with a frequent shot on the shell of a possible partner. The other kind doesn’t knock on the sink, but shakes it, saying, shake yourself out, I want to change with you. The third species turned out to be a polyglot. He uses both of these signals in order to propose an exchange, and he himself understands either of them correctly. So, a meeting of hermits who do not understand each other usually ends in nothing or even turns into a fight. And the polyglot crab, as a rule, successfully changes both with its relatives and with any of a number of living species.

Two species of hermits live in the Black Sea off the Crimean coast. Diogenes Cancer(Diogenes pugilator), named after the famous ancient Greek philosopher who, according to legend, lived in a barrel, prefers the proximity of flat shores. These are small crayfish (up to 30 mm long), varying in color, in which gray and pink colors predominate.

If the sandy soils in the Black Sea are occupied by the hermit Diogenes, then the rocky soils are inhabited by the Clibanaria (pictured). Cancer clibanaria(Clibanarius erythropus) found near rocky coasts. It is several times larger than Diogenes and usually chooses rapan shells as a house. This hermit has a beautiful and bright color, reminiscent of a coral reef inhabitant.

Hermit crabs can become pets just like dogs or cats. Even if they are not so attractive, they are very interesting to watch and sometimes even play with, offering your pet various toys. Caring for crayfish is not difficult, but the child will definitely feel the responsibility entrusted to him. To create the most comfortable living conditions for an animal, it is enough to follow a few simple rules.

Description and photo

Keeping a hermit crab at home- is no longer news today, although many people still know little about these arthropods. They are representatives of the superfamily of decapods and live in the intertidal zone or in shallow waters of coastal coastal zones. Empty mollusk shells are used as a temporary home, and some of them, as adults, move out of the water for a long time, returning to their usual habitat only to reproduce.

The appearance of these animals is explained by their life in a spiral shell. From the outside, only three pairs of legs are clearly visible. The first of them contains claws of different sizes (the larger one is used by many crayfish to close the entrance to their shelter, while the 4th and 5th pairs are much weaker and are needed by the arthropod to fix it in the chosen dwelling).

Did you know? In the absence of free “homes,” crustaceans can offer exchange to their relatives. Crawling up to the shell that interests him, the crustacean knocks on it with his claw, and if its resident is not against the new tenant, then in response he also taps his claw with his claw, as if agreeing to give up his place. However, not all animals are peaceful, so many take a threatening pose and try to scare away the stranger.

The peritoneum of “hermits” is asymmetrical and there is a soft layer of cuticle on it (except for the 1st and 5th parts), which cannot be said about the cephalothorax part. Most often, the right legs of the abdominal part undergo significant reduction, while the left ones are preserved and organize the flow of water (due to this, gas exchange occurs through the soft covering). Simply put, a shell is needed not only to protect the arthropod, but also to preserve its life on land. In females, eggs mature on the left legs of the peritoneum.

Hermit crabs grow throughout their lives, so the question of where to live is always relevant. Some animals look for empty and uninhabited shells, while others can exchange houses among themselves. They never touch snails and generally lead a completely peaceful way of life.

In the modern world, people know about 450 different types of hermit crabs, and some of them are quite successfully grown at home.

About life in nature

Hermit crabs They are quite rightly considered to be travelers in shallow sea waters, because with their dorsal house they travel over rocks and sand in search of food (food for the arthropod is leftover food of organic origin and small algae), sometimes moving quite long distances. If you encounter a mollusk shell on your way, you can be sure that a crayfish that is already familiar to you will appear from it: at a minimum, legs and eyes, and sometimes several specific antennae, acting as organs of smell and touch, will peek out from its shelter.

In addition to mollusk shells, in natural conditions hermits can settle in “houses” gibulla, rapanov, nassa and cerithium, and many crustaceans that occupy the shells of rapans often reach unusually large sizes.

Important!In most cases, the claws of a hermit crab are large in size, and it is based on this indicator that they choose the size of the shells (then the entrance to it is blocked by the claw for greater safety: with this placement, it is almost impossible to pull out the animal).

The lack of their own permanent shell makes arthropods easy prey for numerous predators, which is why the animals have no choice but to constantly look for shelter.

The reason for changing its place of residence can only be its limited space, when the crustacean simply grows out of its previous shell.

Living at home

Keeping wild animals at home is not an easy task, and when it comes to exotic species, things become even more complicated. However, you shouldn’t be scared right away, because in the case of a hermit crab, everything is not as complicated as it might seem at first glance. It is enough to know just a few rules for preparing the habitat and further caring for the arthropod.

Choosing an aquarium

The first thing your pet will need is a spacious aquarium. A tank with a volume of 40-75 liters is suitable only for keeping 2-4 large crayfish, while a volume of 75-150 liters is enough for 10 small or 4-6 large representatives. It is imperative to take into account the animal’s need for social connections, that is, one aquarium must contain at least two individuals.

You can use an old fish aquarium, but if possible, it is better to purchase an acrylic container, since this material retains heat better and maintains humidity.

Attention to the cover

Hermit crabs move very quickly, and the glass walls of the aquarium will not keep them from escaping. For this reason, a lid on the aquarium must be present. The best option is the same glass damper with ventilation holes, which will be an excellent prevention of constant searches for escaped arthropods.

Home improvement

If you have already found a tank for keeping hermit crabs, then the next step is to create the most comfortable environment in it. First of all, organize the substrate- a layer of material laid on the bottom of the selected tank. The only suitable option for this is fine and pure granulated sugar, since large grains of sand may well leave damage on the body of the cancer. To moisten the substrate, you can use salted, non-chlorinated water so that the sand becomes the same as what children use to build various figures.

As an alternative to creating a bottom in an aquarium, you can use coconut fiber, pre-compressed and placed in the same water that you will give to your pets. Aquarium gravel or other materials that cannot hold their shape (for example, calcium-containing sand) are not suitable for organizing the substrate. Some "hermits" like to bury themselves in damp moss, like that intended for reptiles.

Important!The substrate should always be clean, because the formation of mold may well harm your pets. This bedding is completely replaced every 4-6 months, depending on the number of inhabitants of the aquarium, but until this point it should be regularly checked for mold.

The optimal height of the poured layer should be approximately 3-5 times greater than the height of the largest crayfish, which will allow it to easily build a variety of tunnels and caves.

To create comfort for your pets, take care of the “furniture” in their home as well. In natural living conditions, hermit crabs love to climb rocks that appear in the water at low tide and can provide them with food, although they often climb trees. This means that it is necessary to place objects in the aquarium that suit their needs, but it is highly advisable to use unpainted toys.

Perfect fit coniferous branches or hoya roots, leaned against the corner of the tank, and also natural shells, stones, mollusk shells, which can serve as an excellent source of food (it is recommended to boil them before placing them in the tank to ensure sterility). Plastic products can be used as a replacement or addition to branches to develop climbing skills, but just be careful that the crayfish do not start eating the plastic.

In addition to all of the above, you can use it to set up an aquarium broken dishes, large empty shells and even halved coconuts(sold in pet stores). They will be an excellent refuge for your pets, of course, if you make sure in advance that they will not get stuck there.

Important! Under no circumstances should pine branches be used to furnish an aquarium, as this tree causes irritation to arthropods and often has a very toxic effect.

Finally, put a few plants in the tank: for example, bamboo, Venus flytraps and spiderwort, which will be completely safe even if the crayfish eat them.

Water requirements

Considering the natural origin of the described arthropods, it is not surprising that they require access to water, both salty and fresh. This is why there should always be two containers of liquid in the aquarium, deep enough for your pet to climb in and get water. If you keep species that prefer to swim underwater (for example, strawberry hermit crab), then you can organize a mini swimming pool.

The main thing is that the animal can get out of the building without any problems (a container with a slanted bottom would be an excellent option, and small pebbles should be placed closer to the exit, which your pet can easily cling to). When keeping large and small crayfish together, you can put a couple of small stones in the water so that the depth is sufficient for large representatives, and the small ones do not drown.

Important! To create a salty environment, you should not use kitchen salt, since the components it contains can be harmful to crayfish. Salt for sea fish is ideal, which can be easily found in any pet store.

You can also use special, pre-mixed water for crayfish, which already has the optimal level of salinity. Popular brands "Oceanic" And "Instant Ocean".

If you use self-prepared water, be sure to make sure there is no chlorine in it. Chemical compounds and heavy metals found in regular running water can kill hermit crabs by causing blisters to appear on the gills (this is accompanied by quite painful sensations). The longer the water sits, the more chlorine is removed from it, but chloramines still remain. In this regard, when using running water, be sure to buy a dechlorinator.

Optional equipment

As in an aquarium with fish, when keeping hermit crabs, air temperature and humidity levels play a big role in their normal well-being, to control which you will need a hydrometer and thermometer. The optimal temperature values in this case are considered to be +24…+30 °C, and the optimal humidity values are 75-85%. Low humidity levels can cause your pets to suffocate and die a slow, painful death.

A great way to naturally increase humidity is to placement of natural moss in the aquarium, especially since it is also an excellent source of nutrients. You can buy moss for reptiles at the nearest specialized store, and if it is not there, then sponges will be an excellent alternative for the next 2-3 weeks.

Most modern apartments cannot guarantee compliance with the specified temperature conditions throughout the year, so it would be appropriate to install a special heater at the bottom of the aquarium. This is a low-power device that gives an increase of no more than 5 degrees, however, this will be quite enough. The popular tungsten filament is not suitable in this case, as it quickly reduces humidity.

Of course, the ideal option is to create different temperature conditions in different parts of the tank, but achieving such a result is quite difficult.

What to feed hermits

Hermit crabs- omnivorous arthropods, so even if kept at home, no problems with their nutrition should arise. In their natural environment, they eat almost everything they find, which means leftovers from your table (especially canned food) will be a good part of the diet. However, you should not give them industrial food that contains a large amount of preservatives (for example, copper sulfate), or feed crayfish with spicy, hot foods or plants from the onion family.

Seafood and fruits (apples, pineapples, pears, grapes, papaya, etc.) will be very important for the harmonious development of arthropods, which will help maintain the optimal amount of vitamins and other nutrients in the body. They happily eat chicken fillet, fresh shrimp and other fish delicacies sold in any fish store. Of the cereals, special attention should be paid oatmeal, rice, but even if you don’t prepare anything, the crayfish will not refuse specialized food.

Any food should be added to the aquarium in small portions, not only because these animals do not eat much, but also because you need to monitor their reaction to a new product.

If you have several hermit crabs in your aquarium, you can bring them a large fish head and put it in a separate plastic box with large holes in the lid. By moving the crayfish there for the duration of the meal, you will protect the aquarium from a terribly unpleasant odor and disorder. True, as for the latter, it will be so, because these arthropods really like to bury leftover food, which often does not look very aesthetically pleasing, and sometimes can even cause mold to appear. Remains of food from the previous day must be carefully removed, and only after that give your pets a new portion of food.

Did you know? One of the interesting aspects of the life of hermit crabs is their symbiosis with sea anemones. The arthropod places it on its shell and uses it as protection from predators, and in return the sea anemone gets the opportunity to feed on leftover food. When changing the “shell house”, the crayfish transplants its sea anemone to a new place and their interaction continues.

Do Cancers get along with anyone else?

Despite their name, several hermit crabs living in one spacious aquarium can coexist. In addition, many owners believe that social relationships are simply necessary for them and one crayfish will be bored.

It is also no secret that the described arthropods are able to interact well with sea anemones and zoantharians, although it is with the former that they create strong symbiotic connections. Arthropods build good neighborly relationships with various types of plants, although it is best to use Venus flytraps, cleome and bamboo in an aquarium.

In general, if you are interested in unusual animals, then the hermit crab can be called an excellent option for keeping at home, since it is moderately demanding, both in terms of keeping conditions and nutrition.

A reef aquarium is a source of joy, and inhabitants such as hermit crabs provide many positives: inexpensive, hardy, long-lived and, importantly, beneficial. It's always nice to notice a hermit in a new shell one morning - that means everything is as it should be.

Almost any reef aquarium is home to hermit crabs, the main “cleaners” of the aquarium; they often appear after an aquarium owner communicates on a forum, where they advise placing a “handful” of crayfish in any new aquarium where algae problems arise. Often, hermits are the hardest working inhabitants of the aquarium, although many people underestimate them. In my article I will try to explain my warm attitude towards these amazing creatures, very harmoniously arranged and often brightly colored.

Clibanarius tricolor (Blue-legged hermit crab). The most common species in pet stores, also known as the "dwarf blue-legged hermit crab", C. tricolor is considered a staple in the aquarium, although some authors caution against creating excessive competition between individuals for food and available shells, suggesting limiting the number of hermits: no more than 1 individual, or even less, per 10 gallons (about 38 l) of water (Shimek R., 2009).

Scientific classification
Hermit crabs are closer to lobsters and porcelain crabs than to true crabs (brachyurids); Six families of hermit crabs are grouped into the superfamily Paguroidea, which includes more than 1,100 known species:

. Coenobitidae - 2 genera of terrestrial hermit crabs, including the largest known arthropod, Birgus latro.
Diogenidae - 20 genera of "left-handed hermits", including the well-known aquarium species Clibanarius tricolor (blue-legged hermit crab).
Paguridae - 76 genera, including red-legged hermit crabs, Paguristes cadenati and P. digueti.
Parapaguridae - 10 genera of deep-sea hermits, some of which are associated with deep-sea hydrothermal vents.
Pylochelidae - 10 genera of hermits that show no particular interest in shells and prefer wood, sponges or bamboo.
Pylojacquesidae - 2 genera, each with one species.

Biology

Hermit crabs inhabit all seas and oceans, with the exception of the Arctic and Antarctic regions. Many genera of land-dwelling hermits are quite remarkable and play an important role in the pet trade. However, this article is dedicated to marine hermit crabs.

The main and most noticeable characteristic of hermit crabs is their dependence on a rigid structure for shelter and protection from predators. In most cases, hermits use the shells of gastropods, such as whelks, snails or newts, although they are not always limited to them. It has been observed that hermits of the order Pylochelidae use Dentalium vulgare shells, pieces of bamboo or even living sponges. Representatives of the Pagurids family, in particular Discorsopagurus schmitti, colonize the tubes of tube worms such as Sabellidae, and sometimes unceremoniously make their way to living stones.

Hermit crab Calcinus elegans. A very attractive species, but be careful - quite often it targets certain types of snails that benefit the aquarium. In this case, a member of Calcinus elegans destroyed Turbo fluctuosa before occupying its shell. Beginner aquarists often choose C. elegans because of its small size, and as time passes, they get rid of it.

Certain species, such as Ciliopagurus strigatus (red-legged hermit crab), have special requirements for the shell. This hermit, a dandy in yellow and red stockings, is quite common in pet stores, where it is sometimes offered as the Hawaiian hermit crab.

Needless to say, hermits usually do not expect the shell to free itself - before moving to a new “home,” they simply “evict” the shell’s owners and eat them. There are cases of transfer of free shells, more often in terrestrial species, when the largest individual moves into a larger shell, leaving its home vacant for the next largest individual, which, accordingly, leaves its shell for smaller hermits - this situation is advantageous for everyone. A similar change of shells can also occur in an aquarium, when during the night all the hermits “move” into new shells.

Living in a “removable” shell has serious advantages: hermits do not need to enlarge their scutum and take care of it, as other arthropods do; although on the other hand, hermits are forced to limit themselves to only “available” shells. In a situation where there are not enough free shells, the hermits will begin to evict small inhabitants from the shells, since without a shell, hermit crabs are easy prey for predators. The transition to a larger shell is necessary when the hermit sheds its hard exoskeleton; Often, only by finding the remains of the cover, aquarists begin to think about the hidden morphology of hermits. The inability to move into a larger shell slows growth and increases competition.

D.tinctor (anemone hermit crab). With five Calliactid sea anemones, this crab may be clumsy, but it is well protected.

Some hermits, such as Dardanus pedunculatus, use sea anemones (Calliactis sp.) as protection from predators. In this case, the sea anemones also benefit – they catch food particles from the crayfish. The hermit does not part with his sea anemone even when changing the shell, and, if possible, will increase the collection.

Hermit crabs use two pairs of legs to walk, the rest are used to move and hold the body in the shell. The claws (claw-like limbs) can be used as a "door" or lid to block the entrance to the shell in case of "retreat".

Hermit crabs reproduce through the dispersal of eggs by females. Cases of reproduction in aquariums occur quite often. The young shrimp, which resemble shrimp in appearance, will go through several stages of “molting” before they find their first shell.

Conservation in the wild

In general, marine hermit crabs are not endangered, although a significant number of specimens are caught for aquariums. Some authors are concerned about the numbers of blue-footed hermits off the coast of Florida. The catch of more than nine million fish in 2009 has raised concerns about the lack of natural algae controls on reefs, although this has not yet been proven.

Calcinus tibicen. Possibly safe for corals, but certainly not for snails.

Note that the left claw is superior to the right - the main morphological characteristic of this genus.

Coral compatibility

Small hermit crabs, such as C. tricolor and red-legged hermit crabs (P. Cadenati, P. digueti), are the most widely traded hermit crabs: they diligently dispose of uneaten food and dead organisms. In large aquariums, it is sometimes difficult to remove dead fish; hermit crabs, along with other “cleaners,” successfully perform this job. A reasonable number of hermits will not cause any serious problems to the reef aquarium owner, except that they may occasionally eat food caught by corals such as Catalaphylla. Here I would like to remind you that, as experience shows, all hermits are capable of killing other shell-bearing creatures; Thus, Ceriths receive increased attention from C. tricolor; and therefore the expression “coral-safe” does not mean “snail-safe”.

Larger species, such as C. elegans, are considered harmless to corals, although watching a hermit dragging a large shell through fragile corals, destroying them, can cause an aquarist's blood pressure to skyrocket and result in the hermit's deportation. Even larger species, such as Petrochirus diogenes and Ciliopagurus strigatus, can pose an open threat due to their large size and ability to damage corals and even knock over live rocks if they are not firmly anchored.

As always, some aquarists have no problem with hermits, while others cannot cope with them. To preserve the corals and ensure a happy life for the hermits, place a sufficient number of empty shells of varying sizes in the aquarium so that the hermits can change “homes” as they grow. A variety of shells are suitable for hermits, but in my experience, it is worth going to the sea and collecting mollusk shells, such as Littorina littorea and Nucella lapillus. Gastropod shells, Murex, Ceriths and Top Shells are also great for hermits.

As already mentioned, without a sufficient number of empty shells and food, it will be difficult for hermits, so you should not overload the aquarium with these creatures; a few specimens will be enough. I believe that many hermits are starving in modern aquariums with low nutrient levels; as a rule, hermits are only placed in the aquarium when necessary. In other words, when there is enough waste in the aquarium, the hermits will be able to survive, but if there is not enough food for them, and the owner of the aquarium maintains low nutrient levels, they will die. The outlook for many "aquarium guardians" is quite dismal; millions of snails sold as "Turbo" will face the same problem - not to become an appetizer for hermit crabs.

Dardanus lagopodes. This species is rarely found in pet stores.

Hermits are very sensitive to copper-containing drugs; it is believed that they can exist in water conditions that are far from ideal; In their natural environment, they are easier to find in coastal waters than among corals.

Hermit Crab Festival

Hermits are an inexhaustible source of delight and surprise; their appearance amuses. I feed my hermits a spirulina tablet from time to time; Having felt the presence of algae in the water, the hermits take off and start a race. The lucky owner of the tablet will hold it, despite the surgeon fish, who are absolutely happy to have someone holding the algae in a stationary position.

A reef aquarium is a source of joy, and inhabitants such as hermit crabs provide many positive things: inexpensive, hardy, long-lived and, importantly, beneficial. It's always nice to notice a hermit in a new shell one morning - that means everything is as it should be.

Enjoy your hermit crabs and enjoy these amazing creatures: take good care of them and they will look after your aquarium for many years to come.