Marine animals platypus. Strange animal - platypus. Baby platypus hatch from eggs
The platypus is the most primitive animal, combining features of mammals, birds, reptiles and even fish. The platypus is so unusual that it is allocated to a special detachment of One-passers, in which, apart from it, only echidnas and prochidnas are included. However, he also bears little resemblance to his relatives, therefore he is the only species in the platypus family.
Platypus (Ornithorhynchus anatinus).
The first thing that catches your eye when looking at a platypus is its beak. Its presence on the body of the beast is so out of place that European scientists initially considered stuffed platypuses to be fake. But the observations of naturalists in nature proved that the beast with a bird's beak actually exists. In fairness, it should be noted that the beak of the platypus is really not quite real. The fact is that its internal structure does not look like a device of a bird's beak, the platypus has quite animal jaws, they are just covered with skin on the outside. But platypuses have no teeth, auricles, and one of the ovaries is underdeveloped and does not function - these are typical bird features. Also, in platypuses, the excretory openings of the genitals, bladder and intestines open into a common cloaca, which is why they are called single-pass.
The body of this animal is slightly elongated, but at the same time quite rounded and well-fed. The eyes are small, the auditory canals open to the surface of the body with simple holes. The platypus does not hear and see very well, but its sense of smell is excellent. In addition, the amazing beak of the platypus gives this beast another unique quality - the ability to electrolocation. Sensitive receptors on the surface of the beak are able to pick up weak electric fields and detect moving prey. In the animal world, such abilities are noted only in sharks. The tail of the platypus is flat and wide and strongly resembles the tail of a beaver. The paws are short, and swimming membranes are stretched between the fingers. In the water, they help the animal to row, and when they land on land, they fold up and do not interfere with walking.
While walking, the platypus keeps its paws on the sides of the body, and not under the body like typical mammals - this is how reptiles move.
With reptiles, platypuses also have in common a low, unstable body temperature. Unlike most mammals, the body temperature of the platypus averages only 32°! It can be called warm-blooded with some stretch, besides, the body temperature strongly depends on the ambient temperature and can fluctuate between 25 ° -35 °. At the same time, platypuses can, if necessary, maintain a relatively high body temperature, but for this they have to move and eat a lot.
The reproductive system of platypuses is very unusual for mammals: not only do females have one ovary, but there is also no uterus, so they cannot bear cubs. Platypuses solve demographic problems simply - they lay eggs. But this sign makes them related not to birds, but to reptiles. The fact is that the eggs of the platypus are not covered with a hard calcareous shell, but with an elastic cornea like in reptiles. At the same time, the platypus feeds its young with milk. True, it turns out that he is not quite clever. Female platypuses do not have formed mammary glands, instead, the milk ducts open directly to the surface of the body, they are similar in structure to sweat glands and milk simply flows onto the abdomen into a special fold.
The body of the platypus is covered with short brown hair. These animals show sexual dimorphism. Males reach a length of 50-60 cm and weigh 1.5-2 kg, females are noticeably smaller, their body length is only 30-45 cm, and their weight is 0.7-1.2 kg. At the same time, the length of the tail is 8-15 cm. In addition, males differ from females in spurs on their hind legs. In females, these spurs are present only in childhood, then they disappear, in males their length reaches a couple of centimeters. But the most amazing thing is that these spurs secrete poison!
Poison platypus spur.
Among mammals, this is the rarest phenomenon and, apart from the platypus, only slit-tooths can boast of it. Scientists at the Australian University of Canberra have discovered that platypuses have not one, but as many as 5 pairs of sex chromosomes! If in all animals the sex chromosome combinations look like XY (males) or XX (females), then in platypuses they look like XYXYXYXYXY (males) and XXXXXXXXXX (females), and part of the platypus sex chromosomes is similar to those in birds. That's how amazing this beast is!
Platypuses are endemic to Australia, they live only on this continent and nearby islands (Tasmania, Kangaroo). Previously, platypuses were found in vast areas of southern and eastern Australia, but now, due to severe pollution of the main water system of the continent, the Murray and Darling rivers, they have survived only in the eastern part of the mainland. Platypuses lead a semi-aquatic lifestyle, therefore they are closely associated with water bodies. Their favorite habitats are quiet rivers with a calm current and slightly raised banks, usually flowing through forests. On the coasts of the seas, on the banks of mountain rivers with a rapid current and in stagnant swamps, platypuses do not live. Platypuses are sedentary, occupy the same section of the river and do not move far from the lair. Their shelters are burrows that animals dig on their own on the shore. The burrow has a simple device: it is a sleeping chamber with two entrances, one entrance is opened under water, the second - above the water's edge at a height of 1.2-3.6 m in a secluded place (in thickets, under tree roots).
Platypuses are nocturnal animals. They are busy searching for food in the early morning and evening, less often at night, during the day they sleep in a hole. These animals live alone; developed social ties between them have not been found. I must say that platypuses are generally very primitive animals, they do not show much intelligence, but they are very careful. They do not like to be seen, they do not tolerate anxiety, but where they are not touched they can live even on the outskirts of cities. Interestingly, platypuses that live in warm climates hibernate during the winter. This hibernation is short (only 5-10 days) and occurs in July before the breeding season. The biological significance of hibernation is unclear, perhaps animals need it to accumulate energy reserves before the mating season.
Platypuses feed on small invertebrates - crustaceans, mollusks, worms, tadpoles, which are searched for at the bottom of reservoirs. Platypuses are good swimmers and divers, and can stay underwater for a long time. During the hunt, they stir up the bottom silt with their beak and select prey from there. The platypus lays the caught living creatures by the cheeks, and then on the shore with toothless jaws grinds the prey. In order not to inadvertently eat something inedible, platypuses use their electroreceptors, so they can even distinguish a motionless living being from an inanimate object. In general, these animals are unpretentious, but rather voracious, especially during lactation. A case is known when a female platypus ate an amount of food almost equal to her weight during the night!
Swimming platypus.
The breeding season for platypuses occurs once a year between August and November. During this period, the males swim to the sites of the females, the couple whirls in a kind of dance: the male grabs the female by the tail and they swim in a circle. There are no mating fights between males; they also do not form permanent pairs. The female's pregnancy lasts only 2 weeks, during this period she is busy preparing the brood burrow. The brood hole of the platypus is longer than usual, the female arranges litter in it. She does this with the help of ... a tail, capturing a bunch of grass, she presses it to her body with her tail and carries it into the hole. Having prepared the “bed”, the female clogs the hole in order to protect herself from the penetration of predators. She clogs the entrance with earth, which she rams with tail blows. Beavers also use their tail in the same way.
Platypuses are not fertile, the female lays 1-2 (rarely 3) eggs. At first glance, they are difficult to spot in the nest because they are disproportionately small and brownish in color. The size of the platypus egg is only 1 cm, that is, the same as that of passerine birds! The female “incubates” tiny eggs, or rather warms them, curling up around them. The incubation period depends on the temperature, in a caring mother, the eggs are hatched after 7 days, in a bad mother, incubation can take up to 10 days. Platypuses hatch naked, blind and helpless, their length is 2.5 cm. Platypus cubs are as paradoxical as their parents. The fact is that they are born with teeth, the teeth are preserved while the female feeds the cubs with milk, and then they fall out! All mammals do the opposite.
Baby platypus.
The female places the cubs on her belly, they lick the flowing milk from the fold on her abdomen. Platypuses grow very slowly, they begin to see clearly only after 11 weeks! No animal has a longer period of infantile blindness. The female spends a lot of time in the hole with the cubs, leaving her for a short time only for feeding. 4 months after birth, the cubs switch to independent nutrition. Platypuses live in nature up to 10 years, in zoos such a life expectancy is observed only with good care.
Platypus enemies are few. These are pythons and monitor lizards that can crawl into holes, as well as dingoes that catch platypuses on the shore. Although platypuses are clumsy and generally defenseless, but caught, they can use their only weapon - poisonous spurs. Platypus venom can kill dingoes, but for humans, its dose is too small and non-lethal. But this does not mean that the poison is completely harmless. At the injection site, it causes swelling and severe pain that cannot be relieved with conventional painkillers. The pain can last for days or even weeks. Such a strong pain effect can also serve as reliable protection.
The first Australian colonists hunted platypuses for their fur, but this trade quickly died out. Soon, platypuses began to disappear in the vicinity of large cities due to disturbance, river pollution, and land reclamation. Several reserves were created to protect them, and attempts were made to breed platypuses in captivity, but this was fraught with great difficulties. It turned out that platypuses do not tolerate even a little stress very well, all animals that were initially transported to other zoos soon died. For this reason, platypuses are now kept almost exclusively in Australian zoos. But great success has been achieved in their breeding, now in zoos platypuses not only live for a long time, but also breed. Thanks to the protection of their number in nature does not cause concern.
The platypus is a waterfowl belonging to the class of mammals of the monotreme order, or oviparous. This order includes only two families - platypus and echidna. The main difference between platypuses and echidnas from other mammals is the ability to lay eggs.
Where does the platypus live?
The platypus lives only in Australia. In the eastern part of the mainland, the range of the animal is quite extensive - from the Australian Alps and the Tasmanian plateau to the warm rain forests of Queensland. In the northern part of Australia, the platypus is found up to the Cape York Peninsula, and in the central and southern part it is completely extinct, with the exception of about. Kangaroo and the Murray-Darling River Basin. The reason for the disappearance of the platypus in the above regions was the pollution of river waters and intensive hunting for it until the beginning of the 20th century.
The platypus lives only near the coast with clean and fresh water. The home of the platypus is a burrow up to 10 meters long with two entrances. One entrance is in the water, and the other is above the water at a height of 1-3.5 m. Most platypuses are nocturnal, but there are also individuals that hunt well during the day. 
What does a platypus eat?
Platypuses spend a lot of time in search of food - from 8 to 10 hours. Mostly by extracting it in the water, although they often find something to profit from on land. Turning stones near the coast with powerful claws or beaks, they often catch various beetles, larvae, worms and snails. In the water, platypuses eat small fish, crustaceans, tadpoles, frogs, and even aquatic vegetation. To maintain vitality, an animal needs to eat about a quarter of its own weight of various living creatures daily.
The platypus is a dexterous hunter, the animal grabs its prey in a matter of seconds, and the victim almost never manages to get away from such a quick capture. Having caught the prey, the platypus does not eat it immediately, it picks up the catch in the cheek pouches and rises to the surface of the water. Then, lying on the water, he eats prey, rubbing it with horny jaws.
2 families: platypuses and echidnas
Range: Australia, Tasmania, New Guinea
Food: insects, small aquatic animals
Body length: 30 to 80 cm
Subclass oviparous mammals represented by only one detachment - single-pass. This detachment unites only two families: platypus and echidna. single pass are the most primitive living mammals. They are the only mammals that, like birds or reptiles, reproduce by laying eggs. Oviparous feed their young with milk and therefore are classified as mammals. Female echidnas and platypuses do not have nipples, and the young lick the milk secreted by the tubular mammary glands directly from the fur on the mother's belly.
amazing animals
Echidnas and platypuses- the most unusual representatives of the class of mammals. They are called single-pass because both the intestines and the bladder of these animals open into one special cavity - the cloaca. Two oviducts in monotreme females also go there. Most mammals do not have a cloaca; this cavity is characteristic of reptiles. The stomach of oviparous is also amazing - like a bird's goiter, it does not digest food, but only stores it. Digestion takes place in the intestines. These strange mammals even have a lower body temperature than others: without rising above 36°C, it can drop to 25°C, depending on the environment, like in reptiles. Echidnas and platypuses are voiceless - they do not have vocal cords, and only young platypuses have toothless - rapidly decaying teeth.
Echidnas live up to 30 years, platypuses - up to 10. They live in forests, steppes overgrown with shrubs, and even in mountains at an altitude of up to 2500 m.
Origin and discovery of oviparous
Short Fact
Platypuses and echidnas are venomous mammals. On their hind legs they have a bone spur, through which a poisonous liquid flows. This poison causes an early death in most animals, and severe pain and swelling in humans. Among mammals, in addition to the platypus and echidna, only a representative of the order of insectivores is venomous - an open tooth and two species of shrews.
Like all mammals, oviparous descend from reptilian ancestors. However, they separated quite early from other mammals, choosing their own path of development and forming a separate branch in the evolution of animals. Thus, the oviparous were not the ancestors of other mammals - they developed in parallel with them and independently of them. Platypuses are more ancient animals than echidnas, which evolved from them, changed and adapted to the terrestrial way of life.
Europeans learned about the existence of egg-laying almost 100 years after the discovery of Australia, at the end of the 17th century. When the skin of a platypus was brought to the English zoologist George Shaw, he decided that he was simply played, the appearance of this bizarre creation of nature was so unusual for Europeans. And the fact that echidnas and platypuses reproduce by laying eggs has become one of the greatest zoological sensations.
Despite the fact that the echidna and platypus have been known to science for quite a long time, these amazing animals are still presenting new discoveries to zoologists.
wonder beast, platypus as if assembled from parts of different animals: his nose is like a duck's beak, his flat tail looks like it was taken from a beaver with a shovel, webbed paws look like flippers, but are equipped with powerful claws for digging (when digging, the membrane bends, and when walking it gathers into folds, without interfering with free movement). But for all the seeming absurdity, this beast is perfectly adapted to the way of life that it leads, and has hardly changed over millions of years.
At night, the platypus hunts for small crustaceans, mollusks and other small aquatic animals. The tail-fin and webbed paws help him to dive and swim well. The eyes, ears and nostrils of the platypus close tightly in the water, and it finds its prey in the dark under water with the help of a sensitive "beak". On this leathery "beak" are electroreceptors that can pick up weak electrical impulses emitted by movement of aquatic invertebrates. Reacting to these signals, the platypus instantly searches for prey, fills the cheek pouches, and then slowly eats the caught on the shore.
All day the platypus sleeps near the pond in a hole dug by powerful claws. The platypus has a dozen such holes, and each has several exits and entrances - not an extra precaution. To breed offspring, the female platypus prepares a special hole lined with soft leaves and grass - it is warm and humid there.
Pregnancy lasts a month, and the female lays one to three leathery eggs. Mother platypus incubates eggs for 10 days, warming them with her body. Newborn tiny platypuses, 2.5 cm long, live on their mother's belly for another 4 months, feeding on milk. The female spends most of her time lying on her back and only occasionally leaves the burrow to feed. Leaving, the platypus wall up the cubs in the nest so that no one will disturb them until she returns. At the age of 5 months, matured platypuses become independent and leave their mother's hole.
Platypuses were mercilessly exterminated because of their valuable fur, but now, fortunately, they are taken under the strictest protection, and their numbers have increased again.
A relative of the platypus, it does not look like him at all. She, like the platypus, is an excellent swimmer, but she does it only for pleasure: she does not know how to dive and get food under water.
Another important difference: the echidna has brood bag- pocket on the belly, where she puts the egg. The female, although she raises her cubs in a comfortable hole, can safely leave her - an egg or a newborn cub in her pocket is reliably protected from the vicissitudes of fate. At the age of 50 days, the little echidna already leaves the bag, but for about 5 months it lives in a hole under the auspices of a caring mother.
Echidna lives on the ground and feeds on insects, mainly ants and termites. Raking termite mounds with strong paws with hard claws, it extracts insects with a long and sticky tongue. The body of the echidna is protected by needles, and in case of danger it curls up into a ball, like an ordinary hedgehog, exposing the enemy with a prickly back.
wedding ceremony
From May to September, the mating season begins for the echidna. At this time, the female echidna enjoys special attention from males. They line up and follow her in single file. The procession is led by the female, and the grooms follow her in order of seniority - the youngest and most inexperienced close the chain. So, in a company, echidnas spend a whole month, looking for food together, traveling and relaxing.
But the rivals cannot coexist peacefully for long. Demonstrating their strength and passion, they begin to dance around the chosen one, raking the ground with their claws. The female finds herself in the center of a circle formed by a deep furrow, and the males begin to fight, pushing each other out of the ring-shaped pit. The winner of the tournament gets the favor of the female.
This incredible creation surprises with its individuality. It seems that it combines the features of various living creatures in an unimaginable way. Lives and swims in water like a fish; moves on land like an amphibian; lays eggs like a bird; feeds offspring with milk, like a mammal. Scientists for a long time did not believe in the reality of such a creature. They considered him a prank of a joker or a curiosity of nature. But there were no problems with the name. By the presence of a huge beak, the animal received the name - platypus. Sometimes it is also called "duck mole", "water mole", and in England - "flat-foot".
Distribution geography and habitat
The platypus has retained its appearance since the time of the dinosaurs. According to zoologists, its age is estimated at 110 million years. Initially, platypuses inhabited the huge mainland of Gondwana, and after its separation, they managed to survive only in Australia.
AT wild In nature, the animal is found in the eastern part of the southern continent, on the islands of Tasmania and Papua New Guinea. Lives along the banks of water bodies. During the day, platypuses rest in burrows, and in the evening they go hunting and hunt until dawn. In winter, they are often active during daylight hours.
Ways of self-defense
Platypuses dig their dwellings at a height of 1.2–3.6 m above the water level under the overhanging shore. In appearance, the lair of the animal resembles a semicircular cave with a long passage. For convenience and safety, the beast makes 2 exits: one on the surface of the earth, and the other under water. In the dungeon, water moles are saved from bad weather and enemies.
Platypuses can become booty for foxes, large snakes, birds of prey, dingoes. At the same time, it is not easy to catch the animal. The water mole is not one of those who let themselves be offended. In case of danger, males defend themselves with poisonous spurs on their hind legs. The platypus is the only mammal that produces venom. When ingested, it leads to the death of the animal and causes a long-term painful reaction in humans.
Appearance
Outwardly, the platypus looks pretty harmless. Body size the size of a cat, 45–60 cm. Weight up to 2.5–2.7 kg. The body is covered with velvety, thick fur. The back is brown and the belly is silvery white. At the back is a wide, flattened tail, 10–15 cm long. It partly resembles a beaver's tail. Fat reserves are saved in the tail, i.e., it performs the functions of storage. While swimming, the platypus with the help of the tail corrects the movement, “steers”.
The muzzle of the animal has several interesting features:
The paws of the water mole are located not from the bottom of the body, like in other animals, but on the sides, like amphibians. Therefore, the gait is wriggling, reminiscent of the movement of a crocodile or monitor lizard. The limbs end in claws, between which there are membranes. The claws help the platypus dig the ground, and the membranes are necessary for swimming. On land, the flatfoot is clumsy, but in the water it is fast and agile.
Nutrition
The platypus belongs to insectivorous mammals. It feeds on small aquatic animals - crustaceans, snails, tadpoles, larvae, worms. On land, it is guided by hearing and sight, and under water - by touch. During the hunt, the animal emerges to the surface for inspiration at intervals of 1–2 minutes. If necessary, he can hold his breath for up to 5 minutes.
With a wide beak, the duck mole captures prey along with water. Along the edges of the lower jaw, instead of teeth, there are narrow lateral canals formed by thin horny plates. They act as a sieve for filtering the feed. The liquid is forced out of the beak, and the catch remains in the cheek pouches. When the bags behind the cheeks are completely filled, the flatfoot comes to land. With the help of horny plates of the upper and lower jaws and two horny teeth on the surface of the tongue, it grinds food, and then swallows it.
The platypus has an excellent appetite. On the day he eats the amount of food equal to his weight. During the period of incubation of eggs, females eat 2 times more than the average daily norm.
In winter, the animals hibernate for a short time (5–10 days).
reproduction
In July, the mating season begins, which lasts until October. Males show increased aggressiveness. Their poisonous glands noticeably increase in size. They fight for the right to possess a female. The mating ritual takes place in the water. The male makes maneuvers around the female, and then grabs her by the tail with his beak. After that, the couple circles together for a while. At this time, mating takes place.
A pregnant female arranges a special nest in an underground chamber. She drags water plants, willow twigs, eucalyptus leaves into it. Having settled down in the lair, he clogs the entrance with an earthen plug. Precautions help protect yourself and offspring from predators.
Pregnancy lasts three weeks. The offspring of the female brings 1 time in 2 years. The platypus is an egg-laying mammal. One clutch contains 1–2 eggs, rarely 3–4. The eggs are small
- length 1.8–1.8 cm;
- diameter 1.4 - 1.5 cm.
Covered with a thick shell similar to parchment.
Incubation lasts 10–12 days. At this time, the female feeds on earthworms without leaving the nest. The cubs pierce the shell with a special horny tooth, which immediately disappears. They are born blind and open their eyes completely after 11 weeks.
Platypus babies are very tiny, about 2.5 cm. They climb onto their mother's fur and lick the milk that is secreted from the pores on the abdominal cavity and accumulates in special grooves. The mammary glands of the female are absent. Milk The platypus is distinguished by fat content, a large amount of protein and a complete absence of sugar.
The feeding period lasts 4 months. At this time, the mother occasionally leaves the hole to get food for herself. She cannot leave offspring for a long time, as babies are extremely sensitive to temperature conditions. Without heat, they quickly die.
The cubs leave the den in January - March, when they grow up to 40 cm. Puberty in young animals occurs at 2 years. The life span of a water mole is 10 years.
Population changes
After the acquaintance of Europeans with platypuses at the end of the 19th century, these unusual animals began to be massively hunted. Fashionistas fell in love with their beautiful, soft, warm skins. In a short period of time, the animal was brought to the brink of extinction.
In the middle of the 20th century, an attempt was made breed platypuses in captivity. A couple of animals were brought to the US Zoo, but they never received offspring. At the end of the 20th century, the Australian authorities took the rare species under protection, introduced a ban on the export of animals, and created protected areas. Thanks to timely actions, the unique mammal was saved. Now the platypus population in nature is not threatened. Now they are the ones who are revered as living symbols of Australia.
The platypus is an incredible living paradox, fraught with many mysteries.
Ornithorhynchus anatinus (Shaw, )
| Systematics on Wikispecies | Images at Wikimedia Commons |
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History of study
The platypus was discovered in the 18th century during the colonization of New South Wales. A list of the animals of this colony published in 1802 mentions "an amphibious animal of the genus Mole. Its most curious quality is that it has, instead of an ordinary mouth, a duck's beak, which allows it to feed in the mud like birds.
The first platypus skin was sent to England in 1797. Its appearance has generated fierce debate among the scientific community. At first, the skin was considered the product of some taxidermist, who sewed a duck's beak to the skin of an animal that looked like a beaver. This suspicion was dispelled by George Shaw, who studied the package and came to the conclusion that it was not a fake (for this, Shaw even cut the skin in search of stitches). The question arose of which group of animals the platypus belongs to. Already after he received his scientific name, the first animals were delivered to England, and it turned out that the female platypus does not have visible mammary glands, but this animal, like birds, has a cloaca. For a quarter of a century, scientists could not decide where to attribute the platypus - to mammals, birds, reptiles, or even to a separate class, until in 1824 the German biologist Meckel discovered that the platypus still has mammary glands, and the female feeds her cubs with milk. That the platypus lays eggs was only proven in 1884.
The zoological name for this strange animal was given in 1799 by the English naturalist George Shaw - Platypus anatinus, from other Greek. πλατύς - wide, flat, πούς - paw and lat. anatinus - duck. In 1800, Johann-Friedrich Blumenbach, in order to avoid homonymy with the genus of bark beetles Platypus changed generic name to Ornithorhynchus, from other Greek. ὄρνις - bird, ῥύγχος - beak. The Aborigines of Australia knew the platypus by many names, including mallangong, boondaburra and Tambreet. Early European settlers called it "platypus" (duckbill), "duck-mole" (duckmole) and "water mole" (watermole). The name currently used in English is platypus.
Appearance
The body length of the platypus is 30-40 cm, the tail is 10-15 cm, it weighs up to 2 kg. Males are about a third larger than females. The body of the platypus is squat, short-legged; the tail is flattened, similar to the tail of a beaver, but covered with hair, which thins noticeably with age. In the tail of the platypus, like the Tasmanian devil, reserves of fat are deposited. Its fur is thick, soft, usually dark brown on the back and reddish or gray on the belly. The head is round. Anteriorly, the facial section is elongated into a flat beak about 65 mm long and 50 mm wide. The beak is not hard, like in birds, but soft, covered with elastic bare skin, which is stretched over two thin, long, arched bones. The oral cavity is expanded into cheek pouches, in which food is stored during feeding. Down at the base of the beak, males have a specific gland that produces a secretion with a musky smell. Young platypuses have 8 teethhowever, they are fragile and wear out quickly, giving way to keratinized plates.
The paws of the platypus are five-fingered, adapted for both swimming and digging. The swimming membrane on the front paws protrudes in front of the toes, but can be bent in such a way that the claws are exposed outward, turning the swimming limb into a digging one. The webs on the hind legs are much less developed; for swimming, the platypus does not use its hind legs, like other semi-aquatic animals, but its front legs. The hind legs act as a rudder in the water, and the tail serves as a stabilizer. The gait of the platypus on land is more reminiscent of the gait of a reptile - he puts his legs on the sides of the body.
Its nasal openings open on the upper side of the beak. There are no auricles. The eyes and ear openings are located in the grooves on the sides of the head. When the animal dives, the edges of these grooves, like the valves of the nostrils, close, so that neither sight, nor hearing, nor smell can function under water. However, the skin of the beak is rich in nerve endings, and this provides the platypus not only with a highly developed sense of touch, but also with the ability to electrolocate. Electroreceptors in the bill can detect weak electric fields, such as those produced by crustacean muscle contractions, which aid the platypus in its search for prey. When looking for it, the platypus continuously moves its head from side to side during spearfishing.
Organ systems
Features of the sense organs
The platypus is the only mammal that has developed electroreception. Electroreceptors have also been found in the echidna, but its use of electroreception is unlikely to play an important role in finding prey.
Features of metabolism
The platypus has a remarkably low metabolism compared to other mammals; his normal body temperature is only 32°C. However, at the same time, he perfectly knows how to regulate body temperature. So, being in water at 5 ° C, the platypus can maintain normal body temperature for several hours by increasing the metabolic rate by more than 3 times.
platypus venom
The platypus is one of the few venomous mammals (along with some shrews and flint teeth that have toxic saliva, as well as slow lorises, the only known venomous primate genus).
Young platypuses of both sexes have rudiments of horn spurs on their hind legs. In females, by the age of one year, they disappear, while in males they continue to grow, reaching 1.2-1.5 cm in length by the time of puberty. Each spur is connected by a duct to the femoral gland, which produces a complex "cocktail" of poisons during the mating season. Males use spurs during courtship fights. Platypus venom can kill a dingo or other small animal. For a person, it is generally not fatal, but it causes very severe pain, and edema develops at the injection site, which gradually spreads to the entire limb. Pain (hyperalgesia) can last for many days or even months.
Lifestyle and nutrition
reproduction
Every year, platypuses fall into a 5-10-day winter hibernation, after which they have a breeding season. It continues from August to November. Mating takes place in the water. The male bites the female by the tail, and for some time the animals swim in a circle, after which mating takes place (in addition, 4 more variants of the courtship ritual were recorded). The male covers several females; platypuses do not form permanent pairs.
After mating, the female digs a brood burrow. Unlike the usual burrow, it is longer and ends with a nesting chamber. Inside, a nest is built from stems and leaves; The female wears the material, pressing her tail to her stomach. She then plugs the corridor with one or more earth plugs 15-20 cm thick to protect the burrow from predators and floods. The female makes plugs with the help of her tail, which she uses like a mason's trowel. The nest inside is always damp, which prevents the eggs from drying out. The male does not take part in the construction of the burrow and the rearing of the young.
2 weeks after mating, the female lays 1-3 (usually 2) eggs. Platypus eggs are similar to reptile eggs - they are round, small (11 mm in diameter) and covered with an off-white leathery shell. After laying, the eggs stick together with a sticky substance that covers them from the outside. Incubation lasts up to 10 days; during incubation, the female rarely leaves the burrow and usually lies curled up around the eggs.
Platypus cubs are born naked and blind, about 2.5 cm long. When they hatch from an egg, they pierce the shell with an egg tooth, which falls off immediately after leaving the egg. The female, lying on her back, moves them to her belly. She doesn't have a pouch. The mother feeds the cubs with milk, which comes out through enlarged pores on her stomach. Milk flows down the mother's coat, accumulating in special grooves, and the cubs lick it off. The mother leaves the offspring only for a short time to feed and dry the skin; leaving, she clogs the entrance with soil. The eyes of the cubs open at 11 weeks. Milk feeding lasts up to four months; at 17 weeks, the cubs begin to leave the hole to hunt. Young platypuses reach sexual maturity at the age of 1 year.
The lifespan of platypuses in nature is unknown; in captivity they live an average of 10 years.
Population status and protection
Platypuses used to be an object of trade because of their valuable fur, but at the beginning of the 20th century, hunting for them was prohibited. Currently, their population is considered relatively stable, although due to water pollution and habitat degradation, the range of the platypus is becoming more and more mosaic. The rabbits brought by the colonists also caused some damage, which, digging holes, disturbed the platypuses, forcing them to leave their inhabited places.
The Australians have created a special system of reserves and "shelters" (sanctuary), where platypuses can feel safe. Among them, the most famous is the Hillsville Reserve in the state of Victoria, Australia, when these continents were part of the supercontinent Literature