1. Why do the lungs of reptiles have a cellular structure? What effect is achieved by the cellular structure of the lungs in reptiles compared to simple lungs amphibians?

Reptiles have completely switched to terrestrial existence. Their skin does not take part in respiration, only the lungs participate in this process. Their cellular structure increases the surface area, due to which oxygen is absorbed more efficiently.

2. Why is the skin of reptiles covered on the outside with horny scales, scutes?

Answer: Such a coating serves as protection against mechanical damage, changes in ambient temperature.

3. Remember the structural features of amphibian eggs. What is the difference from them reptile eggs?

Amphibian eggs are eggs laid in water. In reptiles, the eggs are covered with a leathery shell or calcareous shell, they are laid on land.

4. Assign the listed units to the appropriate classes.

Classes:
A. Amphibians
B. Reptiles

Squads:
1. Scaly
2. Turtles
3. Tailed
4. Legless
5. Crocodiles
6. Beakheads
7. Tailless

Answer:
A. 3, 4, 7
B. 1, 2, 5, 6.

5. Consider Figure 106 of the textbook (p. 124). Guess where the following animals might live:

  1. Chameleon - in trees (continents, islands)
  2. Roundhead - on the ground (Southeast Europe, Asia)
  3. Aaran gray - desert sands (Central Asia)
  4. Iguana - tropical rainforests (Central and South America).

6. What happens if a lizard injures the tip of its tongue?

Answer: The tip of the tongue performs the functions of touch, smell, taste, if it is damaged, the lizard will lose these functions.

7. Read carefully the descriptions of monitor lizards. It is known that some lizards can exist, dropping their tail in a moment of danger. Can a monitor lizard exist without a tail? Why?

Answer: No, it can't be completely without a tail. The lizard sheds only the tip of the tail, which then grows back. Thus, the monitor lizard gets rid of the predator.

8. Read the descriptions of snakes carefully. What compensates for the poor development of vision and hearing in snakes?

Snakes have a tongue that serves as an organ of touch, smell and taste. By sticking it out and removing it, the snake receives information about smells in the air, and if it touches surrounding objects, then about their surface. In addition, snakes can sense an object at a distance by its movement, feeling the sound wave emanating from it.

9. Which snakes swallow live prey?

Answer: Python, boa constrictor, anaconda, water snake, yellow-bellied snake and other non-venomous snakes.

10. What structural features provide snakes with the ability to swallow prey that is thicker than the diameter of their body?

Answer: Movable jaws contribute to this. The lower jaw is movably connected to the bones of the skull, moves forward and goes back. Its halves are connected on the chin by a flexible ligament and are able to move apart to the sides.

11. What is a creep? How is it formed?

Answer: Creep is the upper cover of the snake (skin), which it sheds during molting.

The gray monitor lizard (Varanus griseus) is a real giant among lizards Central Asia. Its habitat is extremely wide and includes North Africa, Southwest Asia east to Pakistan, Turkmenistan, Uzbekistan, South Kazakhstan, Kyrgyzstan, Azerbaijan. He meets in various types deserts and semi-deserts on fixed and semi-fixed sands, as well as on rocky foothills and along river cliffs. The gray monitor lizard is an exceptionally heat-loving animal, and it entered Kazakhstan from the south; it is not found in the deserts east of the Karatau ridge. He usually avoids humans, however famous cases its entry into cultivated lands and settlements.

In length, a gray monitor lizard can reach 1.5 meters, of which about 90 cm fall on the tail, the lizard weighs about 3.5 kg. For its impressive size, it is sometimes even called the desert crocodile. The body and tail of the lizard are powerful, the head is elongated. The coloration of the upper side of the body of an adult animal is sandy yellow with a pattern of numerous dark spots and dots. The juvenile is easily distinguished by its light gray skin color. The body and tail are encircled by dark transverse stripes, on the back their number varies from 5 to 8, on the tail from 16 to 19. 2-3 brown stripes run along the upper side of the neck.

Gray monitor lizard: features of a lizard

The position of the monitor lizard in the evolutionary series is not entirely clear, but most zoologists believe that snakes are descended from monitor lizards. Indeed, monitor lizards living today have much in common with snakes: the brain of both of them is enclosed in a bone capsule, the neck is significantly elongated, the tongue is long and deeply forked, like that of snakes. In addition, similar signs were noted in the structure of the heart and the microstructure of the stomach. Some habits of monitor lizards resemble snakes. Due to the extensibility of the neck and pharynx, the monitor lizard can swallow big booty and eats, pushing the mouth on the victim. Particularly noteworthy is the fact that the saliva of the gray monitor lizard is poisonous, and its bite causes the same processes in the human body as snake venom.

Monitor lizard is a fast and agile lizard. For a short time it can reach speeds of up to 20 km / h, makes sudden and sharp turns, climbs trees well, where it usually climbs for eggs and chicks of birds nesting there. Despite the fact that the monitor lizard is a desert animal, it swims well, willingly drinks water in captivity and loves to swim.

The monitor lizard is unusually tenacious - it is difficult to put him to sleep in ether vapors. In addition, he for a long time may be under water. In moments of danger, it seeks to hide in a hole, and if this is not possible, it clings to the ground and lies motionless.

The pose of threat in the performance of the monitor lizard is very effective - it rises on its limbs, inflates its throat, opens its mouth wide, sticks out its tongue and begins to shake its tail from side to side, while hissing loudly, periodically taking air into the lungs and releasing it with force.

The gray monitor lizard is characterized by one exceptional phenomenon. Special studies have shown that he is able to tolerate huge doses of cobra and gyurza venom with absolutely no harm to himself. His behavior after the bite does not change and there are no signs of poisoning. There is no swelling or hemorrhage at the site of the bite, and soon its traces disappear completely. As scientists have established, a monitor lizard can carry up to 200 doses of gyurza venom that are fatal to humans and up to 4,000 doses of cobra venom. This feature gives him the ability to hunt large poisonous snakes. In Turkmenistan, for example, he eats cobras and gyurz more than a meter long.

In nature, the gray monitor lizard lives 7-8 years. The long-lived monitor lizard is also known - the gray monitor lizard was kept in the Leningrad Zoo for 17 years.

How does the gray monitor lizard live in nature?

Monitor lizards are diurnal, although in extreme heat they prefer to sit out in shelters, which they serve as holes of rodents and turtles - if necessary, they expand and deepen them. Sometimes in sandy deserts monitor lizards dig holes on their own.

In spring, the monitor lizard is very cautious and inactive. Before appearing on the surface, slowly, barely perceptibly, sticks its head out long neck from the hole, being in a tense pose, for a long time listens and looks closely at everything around. By mid-May, the activity of the monitor lizard increases, it begins to make long transitions from one dune to another. Its footprints are often found on the roads it crosses in search of food. At this time, he leads a wandering lifestyle and spends the night where twilight will catch him. Some zoologists believe that the monitor lizard makes transitions several kilometers long.



Monitor lizards overwinter singly or several individuals in one hole. In Turkmenistan, for example, the monitor lizard is awake only 3-4 months a year, then most individuals plunge into summer hibernation, which turns into winter.

The diet of the monitor lizard includes ground squirrels, gerbils, jerboas, mice. He eats not only freshly caught prey, but also rodents caught in a trap, and he himself often finds himself in it. In spring and early summer, it willingly feasts on young turtles, whose shells have not yet grown strong. It does not pass by birds nesting on the ground and their eggs. He does not disdain and invertebrates. Particularly hungry individuals swallow prey instantly. Two gerbils are enough to saturate a monitor lizard. Sometimes young hares, hedgehogs and even large snakes- vipers, snakes and Central Asian cobras. The monitor lizard kills almost all types of prey by vigorous shaking and clenching of the jaws with sharp teeth.

Having sated, the gray monitor lizard rests. The resting places of the monitor lizard are difficult to confuse with anything. It lies tightly pressed against the substrate, where imprints of regularly arranged rows of ribbed scales remain. Resting, pulls the forelimbs under the body, and puts the elbows to the sides.

Monitor lizards become sexually mature around the third year of life. IN mating season, which falls on April-May, fights often take place between males for the right to possess a female. With claws and sharp conical teeth, lizards inflict deep wounds on each other. In June-early July, the female lays from 6 to 23 eggs, which she guards for several weeks. At the end of August - September, a new generation of monitor lizards is born, and often they immediately go into hibernation.

Keeping a gray monitor lizard at home

Gray monitor lizards are very rarely kept at home. It is difficult to care for them, in addition, they are considered difficult to tame lizards, and only young individuals can eventually get used to a person and even let him close.

If you decide to purchase such an exotic pet, then you will need a spacious horizontal type terrarium to keep it ( minimum dimensions housing for a gray monitor lizard 220x150x60 cm). Both for ventilation side walls terrarium should be made of metal mesh. During the day, the temperature in the terrarium should be maintained at 28-30°C, and at night - 22-24°C. for an exotic temperature pet, an incandescent lamp connected using a thermostat is placed in the terrarium. In addition, a fluorescent lamp with UV radiation must be installed in the monitor's dwelling. The humidity level should be maintained at 30-35%. As a soil, the level of which must be at least 10 cm, sand or a mixture of sand and pebbles is suitable. The monitor lizard will also need hiding places where he can rest, and a reservoir so that he can quench his thirst and swim.

conservation status

Once upon a time, the gray monitor lizard was an ordinary and even numerous lizard. It was mined for the sake of beautiful and durable leather, which was used for tailoring. women's shoes, as well as for the manufacture of wallets, bags and belts. As a result of a widespread decline in numbers, the gray monitor lizard was among the first contenders for the pages of the Red Book. Now it is listed in the IUCN Red Book and the Red Books of Kazakhstan, Uzbekistan, Turkmenistan and Kyrgyzstan, where it is classified as a species of the second category. This means that its numbers are still relatively high, but are declining catastrophically, and in the near future the animal may be on the verge of extinction.

IN natural conditions The monitor lizard has few enemies, but it suffers greatly from a person. People do not like him and are afraid, everywhere unjustified cruelty is manifested to the monitor lizard. Rumors about this large lizard spread like lightning, and people cannot be persuaded. There is a belief that a person who meets a monitor lizard will not have children, or some kind of misfortune will happen. Because of these prejudices, it is destroyed much more often than snakes. Many monitor lizards die on the roads under the wheels of cars. The development of deserts and plowing of lands push him deep into the desert - only here he is in relative safety. Perhaps, like no other lizard, the monitor lizard needs protection and protection.

In contact with

Monitor lizards are the largest lizards in the world. In size, some of them are not inferior to crocodiles, although they are not related to them. Systematically monitor lizards are closer than other lizards to snakes. These reptiles are separated into a separate family of monitor lizards, which includes 70 species.

Gray monitor lizard (Varanus griseus).

All species of monitor lizards are medium or large in size, the smallest of them, the short-tailed monitor lizard, reaches a length of only 20 cm, but most of these reptiles are 0.5-1 m long. large monitor lizard- Komodo (Komodo monitor lizard, Komodo dragon) reaches a length of 3 m, and weighs up to 140 kg! It was the gigantic size of this lizard that prompted people to call this species a dragon. In addition to their large size, monitor lizards differ from other lizards in well-developed muscles, their paws are not only tenacious, but also strong, their stomach is expanded in the middle part, the tail is muscular, whip-shaped and very long. In most monitor lizards, the length of the tail is equal to the length of the body. Unlike real lizards, monitor lizards cannot throw off their tail in case of danger, but they can whip it from side to side. The muzzle of monitor lizards is bluntly rounded, but its features are more reminiscent of snakes than lizards. True, unlike snakes, monitor lizards have round pupils. The scales on the body are relatively large, rounded, the fingers end in long claws. The tongue at the end is bifurcated like that of snakes, with its help monitor lizards can smell smells at a great distance (this is also a typical snake sign). In addition, the skin on the neck in many species can be very swollen. The color of monitor lizards is often dull, gray, sandy, black, brown tones predominate in it. Many monitor lizards, especially young ones, have a spotted and striped coloration.

The Smaragd monitor lizard (Varanus prasinus) is the most striking species. This monitor lizard lives in tropical forests and the green color performs a camouflage function.

Varans - residents warm countries, almost nowhere their range does not go beyond the tropics, and only the gray monitor lizard in the north of the range lives in temperate zone(in Central Asia). Monitor lizards have reached the highest species diversity in Australia and on the adjacent islands, and these animals are also found in South and Central Asia, in Africa. They do not live in the New World. The ranges of most species are extensive, but the Komodo monitor lizard lives only on the Indonesian island of Komodo. This is the rarest and least numerous species.

The habitats of monitor lizards are diverse; according to their ecological preferences, they can be divided into two groups. Some monitor lizards prefer arid desert areas, they are found in dry scrub, woodlands, savannahs, semi-deserts and real quicksand. Other species prefer to stay close to the water, they live on the banks of reservoirs in tropical forests. Finally, there are monitor lizards that prefer woody vegetation and spend most of their time in trees. However, monitor lizards of other groups also climb branches very well.

monitor lizards are active all year round and only the gray monitor lizard in the north of its range hibernates for the winter. Burrows serve as shelter for him, which he seals with an earthen cork for the winter. Other species also dig burrows and spend the night in them. The burrow of the monitor lizard has a length of up to 2-2.5, and for a large Komodo monitor it is up to 5 m in length! A person can freely climb into such a hole. Monitor lizards are sedentary animals, but they do not adhere to strict site boundaries. Most of the time they are in active search walking around a large area during the day. The movements of monitor lizards are not similar to the movements of nimble real lizards. When walking, they strongly bend the spine and this resembles crocodiles. However, sprinting is just an illusion of clumsiness, if necessary, monitor lizards can run fast, climb the branches of trees and shrubs, most species are good swimmers.

The Variegated monitor lizard (Varanus varius) reaches a length of 2 m and is famous for its ability to climb trees.

Monitor lizards live alone, their character is quarrelsome. When they meet at the prey, they immediately enter into a fight. Monitor lizards threaten an opponent with a loud hiss, greatly inflate their stomach and whip their tail. At large species the blow of a thin but strong tail is similar to the blow of a whip, it is very sensitive even for a person. Komodo monitor lizards are more calm about relatives of equal size (smaller ones are chased away), sometimes they can eat together with large prey.

Monitors are active predators. They are not picky in food and catch almost any animal. right size. Depending on the place of residence of a particular species, small lizards, snakes (including poisonous ones), young turtles, small mammals(gerbils, hedgehogs, platypuses), insects. Monitor lizards willingly feast on the eggs of crocodiles, birds, turtles, snakes and regularly check the places of possible clutches. Monitor lizards look for their prey in two ways: they look for prey while walking around the territory and chase it at a run (mobile, but not too frisky species) or find it by smell (sedentary animals, eggs, carrion). Monitor lizards sense smells at a great distance and accurately determine their source by constantly sticking out their tongue and sniffing the air with it. This way of searching is not typical for real lizards, but is typical for snakes. Monitor lizards either swallow their prey whole or tear off pieces with their mouths, holding them with their front paws.

The Komodo dragon (Varanus komodoensis) has a thick and inflexible tail that is not used for defense.

Due to their large size, Komodo monitor lizards eat special foods. The basis of their diet is carrion, primarily the corpses of large animals - wild pigs, deer. However, carrion in nature is a “deficient” product. In this regard, Komodo monitor lizards have developed tolerance for their relatives when eating prey and ... the ability to kill their prey. Of course, it is difficult for a heavy monitor lizard to catch up with a swift-footed deer, but it is not necessary for him to catch it, it is enough to bite, and in a couple of days the table is ready. Even a light bite of a Komodo monitor lizard is fatal, which gave reason to talk about the toxicity of this species. However, these monitor lizards do not have real poison, but there is a unique substitute for it. The saliva of Komodo monitor lizards is very viscous and pathogenic bacteria multiply in it; they feed on small pieces of food stuck between the monitor lizard's teeth. The owner of a bacteriological weapon himself does not suffer at all from such blatant unsanitary conditions in his mouth, but when bitten, the bacteria enter the wound of the victim and cause blood poisoning. A deer or a pig weakens and dies after a few days, and the monitor lizard finds the victim by smell.

The ring-tailed monitor lizard (Varanus acanthurus) is distinguished by its bright spotted coloration.

Monitor lizards breed once a year. The breeding season, depending on the place of residence of the monitor lizard, may vary; in the tropics, it coincides with the beginning of the rainy season. Monitor lizards lay from 7 to 60 eggs in burrows, hollows, anthills and termite mounds. The size of eggs varies from 2 cm in small species to 10 cm in length in the Komodo monitor lizard (such an egg weighs 200 g). The eggs are covered with a soft parchment shell, the incubation period is unusually long - 9-10 months! Parents do not show concern for offspring, young monitor lizards after hatching are completely independent. Medium-sized species (for example, gray monitor lizards) reach sexual maturity by 3 years.

Monitor lizards, due to their large size, have few enemies. The most vulnerable are small species and young individuals, they can even suffer from their own relatives, cases of cannibalism are known among these reptiles. Large snakes can attack monitor lizards, predator birds, crocodiles. Defending themselves, these animals beat the attacker with their tail, hiss, gape their mouths and bite painfully.

The Salvador monitor lizard (Varanus salvadorii) is called the crocodile monitor by the British because of the resemblance of this large lizard to crocodiles.

Monitor lizards also suffer greatly from hunting. In some places, they are hunted for meat and eggs are collected. But most often monitor lizards are killed for the sake of the skin. The skin of these animals is strong, with beautiful pattern and pleasant texture, it is considered an expensive raw material and is used to make exclusive shoes, bags and other accessories. Now some species of monitor lizards are listed in the national Red Books (grey monitor), and the Komodo monitor is in the International Red Book. For humans, these reptiles do not pose a danger. As an exception, there are several cases of Komodo monitor lizards attacking people, but they can be explained by the small size of the victim (most of the dead were teenagers). Obviously, monitor lizards confuse a person of short stature with their usual prey. Now a reserve has been organized to protect the Komodo monitor lizards, the access of tourists to the habitats of these animals is limited and accidents have become a thing of the past. In captivity, most large species of monitor lizards do not take root well, so they are rarely found in zoos.

The monitor lizard is the largest of all lizards living on earth. In size, they are not inferior to crocodiles, although they do not belong to them. family ties. It is also one of the most ancient animals. Systematically monitor lizards stand closer to snakes. These reptiles have a separate family of monitor lizards, including more than 70 species.

So what does a monitor lizard look like?

All types of these big lizards have a medium or large body size - about 0.5-1 m. The largest is the Komodo dragon, which is also called the Komodo dragon. Its length is about 3 m, and it weighs 140 kg! Well, you see, isn't it a dragon?


The Smaragd monitor lizard (Varanus prasinus) is the most striking species. This monitor lizard lives in tropical forests and the green color performs a camouflage function.

Large size and well-developed muscles distinguish large monitor lizards from other individuals. They have tenacious and strong paws, the middle part of the abdomen is somewhat expanded, a long, fleshy, whip-like tail. Many monitor lizards have a tail the same length as the body.

Unlike a real lizard, monitor lizards do not shed their tail in moments of danger, but they whip it from side to side perfectly. The muzzle of the monitor lizard is rounded on the nose, but its general features are more suitable for describing a snake than a lizard. True, this lizard has round pupils, while the snake does not.


The body of the reptile is covered with large, rounded scales, and each finger has a long, sharp claw. At the very tip of the tongue there is a bifurcation, thanks to which the monitor lizard smells smells that are very far away. The color of monitor lizards is not variegated, with a predominance of gray, sandy, black, brown tones. But some young individuals have a spotted and striped pattern.

Where do monitor lizards live

Monitor lizards are amateurs warm climate, so their ranges are located within tropical zone. The largest species diversity of these lizards is found in Australia and on nearby islands.


What does a monitor lizard eat

The monitor lizard is an active predator, not too picky about food. They feed on smaller reptiles (even poisonous snakes), young turtles, insects. A special delicacy for monitor lizards are crocodiles, bird, snake eggs, so regular visits to places of possible clutches are, as it were, a hobby for them. The reptile can swallow the whole prey whole, or bite off pieces with its mouth.

Breeding monitor lizards

Monitor lizards, like most snakes, lay eggs. The mating season is at the beginning of spring. The female lays 15-20 eggs. Since the animal lives in a warm climate, incubation does not occur. However, as well as the responsible upbringing of offspring.


Enemies of monitor lizards in nature

Thanks to large sizes monitor lizards did not make enemies. Vulnerable are only young individuals, which can be eaten even by their own relatives. As a defense, the lizard hits the attacker with a massive tail, hisses, opens its mouth and bites very painfully.


The rarest species

Some species of monitor lizards are listed in the National Red Book, and the Komodo monitor lizard is listed in the International Red Book.