02.05.2020

Coconut thief. Palm thief, or coconut crayfish. Origin of the species and description

Palm thief, or coconut crayfish (Birgus latro) is a species of decapod crayfish from the superfamily of hermit crabs (Paguroidea) with a spectacular appearance. It is able to grow up to relatively giant size, it is likely that the palm thief is the largest among terrestrial arthropods in the world. Indeed, Charles Darwin described him as a "monster". Unlike most other hermit crabs, only very young coconut crabs find and use gastropod shells to protect their exposed belly. Later, tough skin develops there, as over the rest of the body. This protects the crayfish, reduces water loss and does not limit its growth, which allows the palm thief to reach 0.5 meters in length and weigh more than 4 kg.

photo:weedmandan

This huge crustacean is well adapted to life on earth, with long strong legs. It also has large, muscular claws that it uses to peel coconuts and open different shells. This is unique among crabs and explains why this species is called coconut. Its claws are actually so strong that the palm thief can lift objects weighing up to 20kg. Its stalked red eyes and body color varies between islands from purplish blue to orange red. Studies show that the males of this species are significantly larger than the females.

photo:Andrew Lancaster

The palm thief is almost entirely terrestrial and has adapted to it so well that it actually drowns in water. However, it still breathes through modified gills. They are surrounded by a spongy "cloth" that must be kept moist. The coconut crayfish does this by dipping its foot into water and running it over its gills. The palm thief does require some contact with the sea, as it often drinks water to maintain its salt balance, and the females return to the sea to lay their eggs.

Photo: Jungle Diary

During the day, the palm thief sits in a hole where he is protected from withering and enemies, and at night he goes in search of food. As its name suggests, this crayfish feeds on coconuts. When coconuts are no longer available on the ground, he can climb a coconut tree, where he will pluck the coconut with his powerful claws. This crab also feeds on other fruits and other types of crustaceans, which are believed to provide it with calcium for carapace growth.

photo: marcushooi1

After mating on land, the female carries the fertilized eggs to the edge of the sea at high tide and releases the larvae. The larvae are pelagic and remain afloat in the sea for up to 28 days. In the amphibian stage, they are from 21 to 28 days, after which young crayfish occupy empty shells and migrate to land. They molt regularly to ensure their continued growth. Moulting takes place in a safe place and takes about 30 days, after which the palm thief eats the old exoskeleton. These crabs grow very slowly and have been proven to live for more than 40 years, after which they do not increase in size, although they continue to live for many years.

photo: Martin Navratil

The palm thief lives on oceanic islands and small sea islands adjacent to large continental islands in a wide range geographic ranges in the tropical Indo-Pacific region. It inhabits the cracks of rocks and equips sandy holes along coastline. For example, on the island of Olango, Philippines, he lives in holes in coral rock, while on the island of Guam, in Oceania, he makes a hole inside the porous limestone.

Seeing this amazing animal, every faint of heart will shudder with horror and surprise - after all, there is no one in the world more interesting and, at the same time, more terrible than a coconut crab. In any case, among arthropods - after all, he is rightfully considered their largest representative.

The coconut crab has many other "names" such as the thief crab or the palm thief, because this strange animal does indeed steal its prey. Travelers of the past centuries, who visited the islands spread out in the West Pacific Ocean and in Indian Ocean, talk about the fact that the coconut crab hides from prying eyes in the dense greenery of palm trees in order to suddenly grab its prey lying right under the tree or not far from it.

Coconut crab (lat. Birgus latro) is actually not a crab at all, despite its striking resemblance to the arthropod relative mentioned in the name. This is a land hermit crab belonging to the species of decapods.

Strictly speaking, it is also a stretch to call a palm thief a land animal, since part of his life passes in the sea, and even tiny crustaceans are born in the water column. Newborn babies with a defenseless soft abdominal cavity are busily crawling along the bottom of the reservoir in search of a reliable house, which can serve as a nut shell, and an empty shell of a mollusk.

In truth, most of the legends noted this particular feature of it - the first Europeans who arrived on the islands described coconut crabs as creatures with long claws hiding in the foliage of trees, which unexpectedly stretched to the very ground and captured prey, up to sheep and goats. Scientists have confirmed that birgus latro has great strength and can lift up to 30 kg of weight. However, they found out that the crab uses its abilities to drag cargo from place to place, preferring to eat dead animals, crabs and fallen fruit.

How do crayfish manage to exist equally comfortably both in water and on land? It turns out that wise nature provided them with two breathing instruments at once: lungs, ventilated by air on the surface of the earth, and gills, allowing them to breathe underwater. But over time, the second organ loses its functions, and palm thieves have to completely switch to a terrestrial lifestyle.

Those wishing to meet such a miracle would have to go to the tropics - coconut crabs are found on the islands of the Indian Ocean and on some western Pacific islands. It is not easy to see them in the light of day: palm thieves lead night image life, and in solar time hide in rock crevices or in sandy burrows lined with coconut fibers - this helps to maintain the required level of humidity in the home.

And although the version that the crayfish is able to crack a coconut with its front claws failed miserably, its limbs, nevertheless, are sufficiently developed to quickly climb a palm tree trunk or bite off a person’s finger phalanx. And cancer is really not indifferent to coconuts: nutritious pulp is the main dish in its menu, to which it owes its “coconut” name.

Sometimes the diet of crayfish is enriched with pandan fruits, and according to some sources, palm thieves happen to eat their own kind. A hungry crayfish accurately finds the nearest "restaurant": an excellent sense of smell serves as an internal navigator, which brings it to the source of food, even if it is many kilometers away.

As for the “thieves' status” of cancer, this is due to its uncontrollable desire to pull into its mink all sorts of things from the category of the one that lies badly - edible and not very.

Coconut crab meat is not only among the delicacies, but also belongs to aphrodisiacs, so these arthropods are actively hunted. In order to prevent their complete extinction, some countries have established severe restrictions on the capture of coconut crabs.

The body of the coconut crab, like all decapods, is divided into the front part (cephalothorax), on which there are 10 legs, and the stomach. The front, largest pair of legs has large claws (claws), and the left claw is much larger than the right one. The next two pairs, like those of other hermits, are large, powerful with sharp ends, used by coconut crabs to travel along vertical or inclined surfaces. The fourth pair of legs is much smaller than the first three, which allows young coconut crabs to settle in shells of mollusks or coconut shells, to protect themselves. Adults use this pair for walking and climbing. The last, very small pair, which is usually hidden inside the shell, is used by females to care for eggs, and by males for mating.

With the exception of the larval stage, coconut crabs cannot swim, and they will certainly drown if they stay in the water for more than an hour. For breathing, they use a special organ called gill lungs. This organ can be interpreted as a developmental stage between the gills and lungs, and is one of the most important adaptations of the coconut crab to its environment. Gill lungs contain tissues similar to those found in gills, but are suitable for absorbing oxygen from the air rather than water.

The coconut crab has a highly developed sense of smell, which it uses to find food. Like most water crabs, they have specialized organs located on their antennae that determine the concentration and direction of scent.

During the day, these arthropods sit in burrows or rock crevices, which are lined with coconut fibers or foliage to increase the humidity in the dwelling. While resting in its burrow, the coconut crab closes the entrance with one claw to maintain a humid microclimate in the burrow, which is necessary for its respiratory organs.

As the name suggests, this crab feeds on coconuts, and is actually able to climb a coconut tree, up to 6 meters high, where it plucks coconuts with powerful claws if they are not yet available on the ground. If a fallen coconut does not split when it falls, the crab will gut it for a week or even two until it gets to the juicy pulp of the nut. If this dreary job bothers the crab, he lifts the coconut up the tree and throws it down in order to make his work easier. Descending back to the ground, they sometimes fall, but without damage to health they can endure a fall from a height of 4.5 meters. The coconut crab will not refuse other fruits, newborn turtles and carrion. They have also been seen catching and eating Polynesian rats.

Its other name is the palm thief, he received for his love of everything brilliant. If a spoon, fork, or other shiny object gets in the way of a crab, you can be sure that he will certainly try to drag it into his mink.

From the beginning of June to the end of August, the palm thieves begin the breeding season. The courtship process lasts long and tedious, but the mating itself takes place quite quickly. The female carries fertilized eggs for several months on the underside of the abdomen. When the eggs are ready to hatch, the female descends to the seashore at high tide and releases the larvae into the water. During the next three to four weeks, the larvae floating in the water go through several stages of development. After 25 - 30 days, already small crabs sink to the bottom, settle in shells gastropods, and prepare to migrate to land. At this time, babies sometimes visit land, and gradually losing the ability to breathe underwater, they finally move to the main habitat. Coconut crabs reach sexual maturity about five years after hatching, but reach their maximum size only by the age of 40.

Palm thieves live in the tropics, on the islands of the Indian and western parts. Pacific Oceans. Christmas Island in the Indian Ocean has the highest population density of coconut crabs in the world.

Swedish and Australian scientists have confirmed the veracity of all the stories about coconut crabs. So, the inhabitants of the Pacific islands claimed that they could smell, for example, meat or ripe fruits a few kilometers away. And indeed, the special baits planted by the researchers immediately attracted the attention of thieving crabs, who nevertheless disdained the usual pieces of bread that ordinary crabs are greedy for.

The janitor function is, of course, not bad and useful, however, since the birgus latro creature is predominantly nocturnal and not very friendly, bumping into it, locals are not particularly enthusiastic. The decrease in its numbers forced the local authorities to set a limit on the capture of birgus latro. On papua new Guinea is forbidden to include it in restaurant menus, on the island of Saipan - to catch crabs with a shell of less than 3.5 cm, and also from June to September, during the breeding season.

On inner surface The walls of the gill cavities of this terrestrial descendant of hermit crabs develop grape-like folds of skin, in which numerous blood vessels branch. These are real lungs, allowing the use of oxygen from the air filling the gill cavities. The lungs are ventilated due to the movements of scaphognathite, as well as due to the ability of animals to raise and lower the carapace from time to time, for which special muscles serve.

It is remarkable that the gills are also preserved, although they are relatively small in size. The removal of the gills did not harm the breath in the least; on the other hand, the crayfish has completely lost the ability to breathe in water. Submerged in water, the palm thief died after 4 hours. Residual gills, apparently, do not function. The palm thief digs shallow holes in the soil, which he lines with coconut fibers. Charles Darwin relates that the natives on some islands select these fibers from the burrows of the palm thief, which they need in their simple economy. Sometimes a palm thief is content with natural shelters - crevices in rocks, cavities in drained coral reefs, but even in such cases it uses plant material for their lining, which retains high humidity in housing.

The palm thief, or as it is also called the coconut crab, is the world's largest representative of the decapod crabs from the superfamily of hermit crabs. Having studied the way of life of the palm thief, it is extremely difficult to call him a land arthropod, since he spends most of his life under water. Although the palm thief is not really a crab, although it is extremely similar to it. His appearance will make any person afraid, as he looks like terrible monster. And his claws can easily break bones, so it's best to avoid meeting in wild nature with this crab.

habitats

The palm thief also has many different names, for example: a thief - he received this name because he really steals prey, so according to the stories of travelers, this representative arthropod hides in the grass and waits for an opportunity to jump out and drag its prey, which lies on the ground. It also has the name coconut crab - so it was called because he eats mostly coconuts, which is able to break with its powerful front claws.

The coconut crab is related to the common hermit crab and is very similar in appearance. But unlike him, palm thieves only use shells for two years, after which they discard them, since they have very durable exoskeleton.

These representatives of crabs live on the islands of the Indian Ocean, most of the population is found on Christmas Island.

Appearance

The palm thief is the largest of the arthropods. The size of its body can reach a length of up to 40 centimeters, and the mass of the crab reaches four kilograms.

The body of the palm thief, like all representatives of arthropods, is divided into the front part, which includes all limbs and the stomach. The largest pair of legs are large and powerful claws, with which they can easily break coconuts. It can also be noted that the left claw is many times larger than the right one. The next pair of legs have sharp ends, with which they can safely climb any tree. The next pair of legs is responsible for protection when the palm thief is in his shelter and they also use it for walking. The last pair of legs is the smallest, it is mainly located inside the shell and is used only by females to care for eggs, while males use them in the mating process.

The palm thief's body is protected by a powerful calcified exoskeleton. Inside his body there is a special modification capable of producing gas exchange., which allows him to lead a terrestrial lifestyle. And also the arthropod has gills, but they are extremely poorly developed, so that it will not be able to live under water for a long time.

Lifestyle

The diet of the palm thief includes various fruits of pandans, coconuts are a favorite delicacy, and it can also safely eat other representatives of arthropods. But in principle, the palm thief is an omnivore and can eat anything it finds as food.
Coconut crabs live in the ground. To do this, they dig, with the help of claws, shallow minks, in which fibers from coconuts are covered. And I can also live in various crevices and coral reefs.
vigorous activity mainly manifest at night. During the day they hide in their shelters.
Representatives of arthropods live alone. Because they do not like other creatures. They are extremely aggressive towards anyone who enters his territory.

Reproduction of coconut crab

Crabs usually start breeding in the middle of summer, and finish with the advent of autumn. The courtship of the male for the female takes a long time, after which they mate. The female then carries the eggs on her belly. When it's time to hatch, the female puts eggs in water and leaves them there.

Crab cubs are born in the form of larvae, after which they swim freely for about a month, and then look for a place for themselves. permanent life. Having found a shelter, they sit there until they have a shell. This period lasts about twenty days. After that, they begin to molt, during which the body of the crab changes. Now he becomes like an ordinary representative of the palm thief.

Still a young crab lives mainly under water, but is already beginning to crawl out a little to the surface. As soon as the palm thief completely moves to land, he throws off the shell from his back and becomes like a hermit crab. They become fully grown crabs only in the fifth year of their life. And they reach their maximum size only by the age of forty.

Value for a person

This representative of crabs has always been very valuable for its uniqueness. Palm thief meat is a very rare delicacy.. It tastes like lobster or lobster meat. And also it is highly valued for the fact that its meat gives a strong aphrodisiac effect that promotes sexual desire.

Due to the mass hunting of crabs, the authorities of some countries were forced to ban the hunting of palm thieves in order to preserve their population.

Representatives of palm thieves have a very highly developed sense of smell, so they can smell food for several tens of kilometers.
Coconut crabs have an excellent ability to climb trees, so they can safely climb within a few seconds to a height of about ten meters.
Although the crab's appearance is intimidating and capable of terrifying anyone who sees it. Big land crab is absolutely safe for a person if he does not touch it, in which case the crab can easily break the bones of the hand with its powerful claws.
In Guinea, palm thief meat was traditional dish, until the moment when the government of the country banned the capture of these representatives of arthropods. Now he is a rare delicacy, for which you will have to pay a large sum Money.

Just imagine you will see such a "cockroach" in your trash can :-)

The palm thief (Birgus latro), the coconut crab or thief crab, became famous after researchers from the universities of Lund (Sweden) and New South Wales (Australia) found that it has the same smell mechanisms as insects. This is the largest arthropod in the world (recall, they also include crustaceans, insects, spiders), up to half a meter long and weighing up to 4 kg. Like any crab, it has bristles and hairs of different lengths - tactile receptors.

But the coconut crab is unique in its kind, its sense of smell is as highly developed as that of insects, and besides, it has organs of smell that ordinary crabs lack. This feature of birgus latro developed after it emerged from the water and settled on land.

Clickable 2000 px

This thief with an incredible sense of smell is a creature whose appearance gave rise to many legends on the islands of the Pacific and Indian Oceans. If this giant crab is thrown into water, it will suffocate. His story is a typical example of "convergent evolution". So researchers call evolution, in which the same needs cause the same adaptation in organisms far from each other.

Like any crab, it has bristles and hairs of different lengths - tactile receptors. But the coconut crab is unique in its kind, its sense of smell is as highly developed as that of insects, and besides, it has organs of smell that ordinary crabs lack. This feature of birgus latro developed after it emerged from the water and settled on land. Swedish and Australian scientists have confirmed the veracity of all the stories about coconut crabs. So, the inhabitants of the Pacific islands claimed that they could smell, for example, meat or ripe fruits a few kilometers away. And indeed, the special baits planted by the researchers immediately attracted the attention of thieving crabs, who nevertheless disdained the usual pieces of bread that ordinary crabs are greedy for.

In "childhood" birgus latro is not too different from a hermit crab: he drags his shell along with him and spends almost all his time in the water. But having once left the larval state and left the water, he is no longer able to return there, and at some point even carry a shell-house behind him. Unlike the abdomens of hermit crabs, its abdomen is not an Achilles' heel and gradually hardens, and the tail curls under the body, protecting the body from cuts. Thanks to special lungs, he begins to breathe out of the water. Once on solid ground, the coconut crab begins to drag everything that is poorly hidden (according to local residents, it is tempted not only by food, but also by any shiny objects), and demonstrates its strength by splitting coconuts with its claws, after which it climbs up the palm trees to a height up to 6 m.

In truth, most of the legends noted this particular feature of it - the first Europeans who arrived on the islands described coconut crabs as creatures hiding in the foliage of trees with long claws that suddenly stretched to the very ground and captured prey, up to sheep and goats. Scientists have confirmed that birgus latro has great strength and can lift up to 30 kg of weight. However, they found out that the crab uses its abilities to drag cargo from place to place, preferring to eat dead animals, crabs and fallen fruit. If he wants to eat coconut, he cracks nuts, but it's a job - it takes weeks. Therefore, given that it moves well and fairly quickly, the thief crab prefers to use its powerful sense of smell in order to find edibles that do not have to be fiddled with - for example, food waste.

The janitor function is, of course, not bad and useful, however, since the birgus latro creature is predominantly nocturnal and not very friendly, stumbling upon it, the locals are not particularly enthusiastic. There are, however, those who are looking for a meeting with him: the crab is a well-known delicacy, and its meat is considered an aphrodisiac. The decrease in its numbers forced the local authorities to set a limit on the capture of birgus latro. In Papua New Guinea, it is forbidden to include it in restaurant menus, on the island of Saipan - to catch crabs with a shell less than 3.5 cm, and also from June to September, during the breeding season.

With regard to reproduction, courtship in thief crabs can be long and difficult. The female, being slightly lighter than the male, carries fertilized eggs under her body, they are protected by three special processes.

When the eggs mature, the female goes to the surf line and leaves them at high tide so that the larvae can swim in the water for about a month. The "babies" then look for solid protection - a shell or nut shell - and exist as hermit crabs until they grow up to 2.5 cm in length. From that moment on, they shed their shells and their abdomens gradually harden through several phases of mutation during which they hide behind rocks. Apart from mating, the coconut crab does everything slowly and calmly: its growth phase is very long. So long that no one has yet been able to find out how long the thief crab lives.

scientific classification
Kingdom: Animals
Type: Arthropod
Subtype: Shellfish
Class: Higher crayfish
Detachment: Decapods
Superfamily: Hermit crabs
Family: Coenobitidae
Genus: Birgus
View: Palm Thief

On the inner surface of the walls of the gill cavities, this terrestrial descendant of hermit crabs develop grape-like skin folds, in which numerous blood vessels branch. These are real lungs, allowing the use of oxygen from the air filling the gill cavities. The lungs are ventilated due to the movements of scaphognathite, as well as due to the ability of animals to raise and lower the carapace from time to time, for which special muscles serve.

It is remarkable that the gills are also preserved, although they are relatively small in size. The removal of the gills did not harm the breath in the least; on the other hand, the crayfish has completely lost the ability to breathe in water. Submerged in water, the palm thief died after 4 hours. Residual gills, apparently, do not function. The palm thief digs shallow holes in the soil, which he lines with coconut fibers. Charles Darwin relates that the natives on some islands select these fibers from the burrows of the palm thief, which they need in their simple economy. Sometimes the palm thief is content with natural shelters - crevices in the rocks, cavities in drained coral reefs, but even in such cases he uses plant material to line them, which retains high humidity in the dwelling.

Seeing this amazing arthropod, every faint of heart will shudder with horror and surprise - after all, there is no one in the world more interesting and, at the same time, more terrible than a coconut crab. In any case, among arthropods - after all, he is rightfully considered their largest representative.

(Total 33 photos)

1. The coconut crab has many other "names": for example, a thief crab or a palm thief - after all, this strange arthropod really steals its prey. Travelers of past centuries, who have visited the islands spread in the West Pacific Ocean and in the Indian Ocean, talk about the fact that the coconut crab hides from prying eyes in the dense greenery of palm trees in order to suddenly grab its prey lying right under a tree or nearby From him.

2. Coconut crab (lat. Birgus latro) is actually not a crab at all, despite its striking resemblance to the arthropod relative mentioned in the name. This is a land hermit crab belonging to the species of decapods.

Strictly speaking, it is also a stretch to call a palm thief a land arthropod, since part of its life passes in the sea, and even tiny crustaceans are born in the water column. Newborn babies with a defenseless soft abdominal cavity are busily crawling along the bottom of the reservoir in search of a reliable house, which can serve as a nut shell, and an empty shell of a mollusk.

3. In "childhood" birgus latro is not too different from a hermit crab: he drags his shell along with him and spends almost all the time in the water. But having once left the larval state and left the water, he is no longer able to return there, and at some point even carry a shell-house behind him. Unlike the abdomens of hermit crabs, its abdomen is not an Achilles' heel and gradually hardens, and the tail curls under the body, protecting the body from cuts. Thanks to special lungs, he begins to breathe out of the water.

4. How do crayfish manage to exist equally comfortably both in water and on land? It turns out that wise nature provided them with two breathing instruments at once: lungs, ventilated by air on the surface of the earth, and gills, allowing them to breathe underwater. But over time, the second organ loses its functions, and palm thieves have to completely switch to a terrestrial lifestyle.

5. Those wishing to meet such a miracle would have to go to the tropics - coconut crabs are found on the islands of the Indian Ocean and on some western Pacific islands. It is not easy to see them in daylight: palm thieves are nocturnal, and in sunny times they hide in rock crevices or in sandy burrows lined with coconut fibers - this helps to maintain the required level of humidity in the home.

6. And although the version that the crayfish can crack a coconut with its front claws failed miserably, its limbs are nevertheless developed enough to quickly climb a palm tree trunk or bite off a person’s finger phalanx. And cancer is really not indifferent to coconuts: nutritious pulp is the main dish in its menu, to which it owes its “coconut” name.

7. Sometimes the diet of crayfish is enriched with the fruits of pandans, and according to some sources, palm thieves happen to eat their own kind. A hungry crayfish accurately finds the nearest "restaurant": an excellent sense of smell serves as an internal navigator, which brings it to the source of food, even if it is many kilometers away.

8. As for the "thieves' status" of cancer, this is to blame for its irrepressible desire to pull into its mink all sorts of things from the category of that which is bad - edible and not very.

9. The body of the coconut crab, like all decapods, is divided into the front part (cephalothorax), on which there are 10 legs, and the stomach. The front, largest pair of legs has large claws (claws), and the left claw is much larger than the right one. The next two pairs, like those of other hermits, are large, powerful with sharp ends, used by coconut crabs to travel along vertical or inclined surfaces. The fourth pair of legs is much smaller than the first three, which allows young coconut crabs to settle in shells of mollusks or coconut shells, to protect themselves. Adults use this pair for walking and climbing. The last, very small pair, which is usually hidden inside the shell, is used by females to care for eggs, and by males for mating.

10. With the exception of the larval stage, coconut crabs cannot swim, and they will certainly drown if they stay in the water for more than an hour. For breathing, they use a special organ called gill lungs. This organ can be interpreted as a developmental stage between the gills and lungs, and is one of the most important adaptations of the coconut crab to its environment. Gill lungs contain tissues similar to those found in gills, but are suitable for absorbing oxygen from the air rather than water.

11. The coconut crab has a highly developed sense of smell, which it uses to find food. Like most water crabs, they have specialized organs located on their antennae that determine the concentration and direction of scent.

12. During the day, these arthropods sit in burrows or rock crevices, which are lined with coconut fibers or foliage to increase the humidity in the dwelling. While resting in its burrow, the coconut crab closes the entrance with one claw to maintain a humid microclimate in the burrow, which is necessary for its respiratory organs.

13. As the name suggests, this crab feeds on coconuts, and is actually able to climb a coconut tree, up to 6 meters high, where it plucks coconuts with powerful claws if they are not yet available on the ground. If a fallen coconut does not split when it falls, the crab will gut it for a week or even two until it gets to the juicy pulp of the nut. If this dreary job bothers the crab, he lifts the coconut up the tree and throws it down in order to make his work easier. Descending back to the ground, they sometimes fall, but without damage to health they can endure a fall from a height of 4.5 meters. The coconut crab will not refuse other fruits, newborn turtles and carrion. They have also been seen catching and eating Polynesian rats.

14. Another name for it is the palm thief, he received for his love for everything shiny. If a spoon, fork, or other shiny object gets in the way of a crab, you can be sure that he will certainly try to drag it into his mink.

15. From the beginning of June to the end of August, the palm thieves begin the breeding season. The courtship process lasts long and tedious, but the mating itself takes place quite quickly. The female carries fertilized eggs for several months on the underside of the abdomen. When the eggs are ready to hatch, the female descends to the seashore at high tide and releases the larvae into the water. During the next three to four weeks, the larvae floating in the water go through several stages of development. After 25 - 30 days, already small crabs sink to the bottom, settle in the shells of gastropods, and prepare to migrate to the ground. At this time, babies sometimes visit land, and gradually losing the ability to breathe underwater, they finally move to the main habitat. Coconut crabs reach sexual maturity about five years after hatching, but do not reach their maximum size until they are 40 years old.

16. Palm thieves live in the tropics, on the islands of the Indian and Western Pacific Oceans. Christmas Island in the Indian Ocean has the highest population density of coconut crabs in the world.

17. Swedish and Australian scientists have confirmed the veracity of all the stories about coconut crabs. So, the inhabitants of the Pacific islands claimed that they could smell, for example, meat or ripe fruits a few kilometers away. And indeed, the special baits planted by the researchers immediately attracted the attention of thieving crabs, who nevertheless disdained the usual pieces of bread that ordinary crabs are greedy for.

18. The janitor function is, of course, not bad and useful, however, since the birgus latro creature is predominantly nocturnal and not very friendly, stumbling upon it, the locals are not particularly enthusiastic. The decrease in its numbers forced the local authorities to set a limit on the capture of birgus latro. In Papua New Guinea, it is forbidden to include it in restaurant menus, on the island of Saipan - to catch crabs with a shell less than 3.5 cm, and also from June to September, during the breeding season.

19. On the inner surface of the walls of the gill cavities, this terrestrial descendant of hermit crabs develop grape-like skin folds, in which numerous blood vessels branch. These are real lungs, allowing the use of oxygen from the air filling the gill cavities. The lungs are ventilated due to the movements of scaphognathite, as well as due to the ability of animals to raise and lower the carapace from time to time, for which special muscles serve.

It is remarkable that the gills are also preserved, although they are relatively small in size. The removal of the gills did not harm the breath in the least; on the other hand, the crayfish has completely lost the ability to breathe in water. Submerged in water, the palm thief died after 4 hours. Residual gills, apparently, do not function. The palm thief digs shallow holes in the soil, which he lines with coconut fibers. Charles Darwin relates that the natives on some islands select these fibers from the burrows of the palm thief, which they need in their simple economy. Sometimes the palm thief is content with natural shelters - crevices in the rocks, cavities in drained coral reefs, but even in such cases he uses plant material to line them, which retains high humidity in the dwelling.

Fashion & Style

1 0 0

If you find an error, please select a piece of text and press Ctrl+Enter.