Turtle head It has a streamlined shape and medium size, which allows you to quickly hide it inside a safe haven. However, there are species with large heads that are poorly or not fit in their shell at all. In some representatives of the genus, the tip of the muzzle resembles a kind of "proboscis", ending with the nostrils.

Due to the peculiarities of life on dry land, the turtles look into the ground. At the water representatives of the detachment, they are located closer to the crown and are directed forward and upward. The neck of most turtles is short, however, in some species it can be comparable to the length of the carapace.

Does a turtle have teeth? How many teeth does a turtle have?

For biting and grinding food, turtles use a hard and powerful beak, the surface of which is covered with rough protuberances that replace teeth. Depending on the type of food, they can be as sharp as a razor (in predators), or jagged (in herbivores). The ancient turtles that lived 200 million years ago, unlike modern individuals, had real teeth. The tongue of the turtles is short and serves only for swallowing, and not for capturing food, so it does not protrude outside.

Limbs and tail turtles.

Total turtles 4 paws. The structure and functions of the limbs depend on the lifestyle of the animal. Species that live on land have flattened forelimbs, adapted for digging, and powerful hind legs. Freshwater turtles are characterized by the presence of skinny membranes facilitating swimming between the fingers on all four paws. In sea turtles, extremities in the process of evolution were transformed into peculiar flippers, and the size of the front ones far exceeds the rear ones.

Almost all turtles have a tail, which, like the head, hides inside the shell. In some species, it ends with a nail-shaped or pointed spike. Turtles have well-developed color vision, which helps them to find food, and excellent hearing, allowing them to hear enemies at a considerable distance.

Turtles molt like many reptiles. In land species, molting affects the skin in a small amount; in water turtles, molting occurs imperceptibly. During the molting, transparent shields exfoliate from the shell, and the skin from the paws and neck comes off in tatters.

Lifetime of a turtle in natural conditions can reach 180-250 years. With the onset of winter cold or summer drought, the turtles go into hibernation, the duration of which can exceed six months.

How to determine the sex of the turtle?

Due to the weakly expressed sexual characteristics of turtles, it is very difficult to determine which animal is “boy” and who is “girl”. Nevertheless, if you approach the issue with care, having studied some of the external and behavioral characteristics of these exotic and interesting reptiles, then finding out their gender identity does not seem so difficult.

• Shell. In the female, it usually has a more elongated, elongated shape compared with the male.

• Plastron (lower part of the shell). Turn the turtle over and take a close look at it - the shell from the side of the abdomen closer to the anus in the female turtles is flat, the males are slightly concave (by the way, such a nuance facilitates the mating process).

• Tail. In male turtles, the tail is slightly longer, wider and thicker at the base, most often bent down. Tail "ladies" short and straight.

• Anal opening (cloaca). In females, it is somewhat closer to the tip of the tail, resembles an asterisk or a circle compressed on the sides. In male turtles, the anus has a narrow oblong or slit shape.

• Claws. In almost all species, except for the leopard tortoise, the claws of males on the forelegs are longer than those of females.

• Trench notch. The males have a notch in the form of a letter V in the back of the shell, it is necessary for mating turtles.

• Behavior. Male turtles are most often more active, and in the mating season they are distinguished by their aggressiveness towards their rival and the “lady of the heart”, they chase her, trying to bite, and nod their head in amusing ways. A female at this time can quietly observe the “grooming” by hiding her head in the shell.
• Some species of turtles have specific differences between females and males, for example, in color, size or shape of the head.

Where do turtles live?

Turtles live in all tropical areas and areas with a temperate climate. They inhabit not only land, but also freshwater bodies of water, as well as warm sea and ocean expanses. Turtles do not live only in the icy deserts of the Arctic, Antarctica and the harsh conditions of Greenland. The distribution area of ​​these reptiles does not include New Zealand and the countries of the Pacific coast of Latin America.

Land turtles inhabit the steppes, deserts, semi-deserts and shrouds of Africa, North and South America, Australia, Albania, Greece and Italy, India and Pakistan, Russia, Kazakhstan, Uzbekistan and other Asian countries. Freshwater reptiles have chosen rivers, lakes and swamps of the temperate zone of Eurasia, as well as reservoirs of Africa, South America, Europe and Asia.

Turtles living in Russia:

• leatherback turtle (lat. Dermochelys coriacea),
• Far Eastern tortoise (lat. Pelodiscus sinensis),
• loggerhead (lat. Caretta caretta),
• marsh turtle (lat. Emys orbicularis),
• Caspian tortoise (lat. Mauremys caspica),
• Mediterranean tortoise (lat. Testudo graeca).

What do turtles eat in nature?

Turtles food directly depends on the species and their habitat. For example, for land turtles the basis of nutrition is vegetable food: young tree branches, fruits and vegetables, grass and mushrooms. However, to maintain the protein balance in the body, they sometimes use snails, slugs and worms. The need for moisture in land species is fully satisfied by eating the juicy parts of plants, but when the opportunity arises, they drink water with great pleasure.

Freshwater and sea turtles are typical predators in nature. To maintain vitality, their “menu” should include small fish, frogs, snails and crustaceans (some species of turtles love to feast on shrimps, small cuttlefish and squid), bird eggs, insects (crickets, grasshoppers), clams and arthropods. Large turtles can even catch a bird, such as a duck. But along with this, aquatic turtles eat plant food in a small amount, and herbivorous individuals eat animal food. There are freshwater turtles, which at a young age eat frogs and fish, and when mature, they switch to plant food. There are also omnivorous species of sea turtles.

Some representatives of the kind of menu is very specific. For example, box turtles feed on poisonous mushrooms, leatherback turtles and biss eats poisonous jellyfish. From this food, the turtle meat becomes poisonous, which can lead to poisoning of those who catch and eat these turtles.

How to feed a turtle at home?

Captive turtles need a balanced diet. In the food of land reptiles include leaves of cabbage, dandelion or lettuce, the pulp of apples, cucumbers, beets and tomatoes. Boiled eggs are added as protein foods, and vitamin supplements are added as needed.

Aquatic turtles can be fed at home with dried daphnia, bloodworms and earthworms, boiled chicken or beef meat. Sometimes you need to give live aquarium fish, as well as cockroaches and other small insects. As plant additives for aquatic reptiles, algae are grown in a separate aquarium; however, if this is not possible, lettuce leaves will do.

The main condition for feeding animals is moderation. Young individuals are given food twice a day; adults only need one feeding. Once a week, turtles need to arrange a fasting day.

Turtle breeding.

Depending on the species, place and habitat, turtles mating season occurs at different times. However, for all members of the genus, it has common features. Males arrange real battle for the right to mate with a female. Land specimens try to flip an opponent with blows of its shell or force it to run away, while aquatic turtles pursue their opponent, beat and bite him with sharp beaks. Having banished a competitor, the male turtle begins to care for the female, forcing it to take a comfortable position for the mating process. Attracting a female, males can “sing” serenades to her or stroke her face with their front paws.

For laying off spherical or ellipsoid turtle eggs, the surface of which is covered with durable shells or leathery skin, female individuals use pits dug in the sand, their own holes or even crocodile nests. The laying of the turtle is covered with soil and is compacted by plastron blows.

Depending on the type, the number of laid eggs can be from 1 to 200. The incubation period varies from 2 to 3 months, but for some species this period can be as long as six months or more. During the breeding season, the female turtle is able to make several clutches.

In the way of life, turtles are solitary animals and find mates only for the period of mating, although it is typical for some species to gather in small groups for wintering.

How to care for a turtle at home?

The maintenance of turtles at home, both land and water, is very popular today. These animals are unpretentious, and care for turtles is very simple, so even children can follow the pets. However, you should not choose large species of turtles as pets, which can reach more than half a meter in length. Specially equipped aquariums, terrariums or cages for turtles, in which conditions are created as close as possible to the natural habitat, are designed for comfortable living of reptiles in apartment conditions.

At the site of the tortoise should install two thermometers to monitor the temperature of air and water. It is advisable to use alcohol or liquid crystal measuring devices, as they are safer. The water in the aquarium should be cleaned with filters, and in their absence change every day.

The hygiene of aquatic inhabitants consists in the removal of algae that have grown on the shell. Land reptiles need to be bathed daily in warm water with the addition of baking soda, washing away food debris and adhering soil. The overgrown claws of a turtle should definitely be shortened with a small nail file. In winter, pets should be periodically irradiated with rays of a quartz lamp, making a peculiar sun bath. You must ensure that the light does not fall directly into the eyes of the animal.

About feeding turtles at home is described in detail just above.

Subject to the rules of animal care at home, turtles can live up to 170 years.

Appearance

Turtles of only 3 cm in length are born and continue to grow throughout their life. The size of an adult individual can be 15–25 cm. But, as a rule, they are not very large: males are smaller - 13–20 cm, females are slightly larger than the representatives of the stronger sex - 15–23 cm.

A medium-brown, small-sized head with the slightest danger hides under a rounded strongly convex shell, the color of which, depending on the individual, can be any - sandy, green, brown with vague dark spots.

Paws of the same color as the head have four fingers, rather than three, like other brethren.

Purchasing a healthy pet

In order not to run the next day to the vet for treatment, it is better to immediately buy a healthy turtle. Pay attention to everything:

• observe her behavior, activity and movement coordination,
• the appearance must be free from damage and the presence of inappropriate stains,
• the shell of the correct form with smooth shields densely adjacent to each other,
• the best way to determine whether a turtle is healthy is to look into her mouth: the mucosa should be free of plaque, light pink and without viscous saliva,
• from the nose should not be discharge.

Do not forget about transportation. For short distances in the warm season, it can be carried in a cardboard box, putting paper there. In autumn and winter, it is better to cover the passenger with a warm cloth and place a heating pad there.

Taming

An animal that has just been bought on the market and brought home can refuse to eat, for months to get used to the new environment.

To the reptile was not afraid and quickly settled down, you need to feed her.

She will like a specially prepared dish of green salad leaves, grated pears, bananas, apples, persimmons, carrots, which can be sprinkled with a small amount of vanilla.

To improve the pet's digestion, you can organize a warm bath for him.

Central Asian tortoise: content in a terrarium

In residential conditions, they contain a turtle in a spacious terrarium with a volume of 60 to 100 liters per individual with a container width three times the size of a reptile. Humidity should be in the range of 70-80%.

Warm place can be arranged using a 40–100 watt electric lamp. Air temperature should vary from 25 to 35 ° C. In order for the animal to not get burned, it is important to adjust the height of the lamp.

In a cold corner daytime temperatures should not fall below 20 ° C.

The recommended length of daylight hours is at least 12 hours. At night, the lamp is still better off. For normal life of the pet need ultraviolet light, and preferably with a spectrum of UVB 10%.

Priming. Since the Central Asian tortoise belongs to a species of burrowing animals, the presence of soil with a layer of at least 15 cm in the terrarium is mandatory. It can be sand, hay, wood chips, small river pebbles mixed with peat, calcined garden soil. On large pebble reptiles will grind down claws.

Vegetation. As an additional decoration and the presence of constant fresh green in the terrarium, it is recommended to sow oats or wheat along the walls.

Water. It is not necessary to pour water into the terrarium, it is enough to put a drinker or a tank with separated water at room temperature, in which the turtle can safely lie as in a bath. Deciding to install a bath, do not forget about the basic rules and the permissible water level - the edges of the tank should be slightly submerged in the ground, and the liquid level should not exceed half the height of the shell.

Aviary in the open air

In order for the Central Asian tortoise to receive more sunlight and fresh air, in summer it can be kept outside in a spacious and well-equipped aviary with dimensions of 2x2 m and more.

A well-buried (30 cm) fence and large stones placed in its corners will help to avoid undermining and escaping a pet. At night, she will hide in a house-hole, which you yourself can do.

You can put a shallow tank with bathing water, with which she can independently get out.

Central Asian tortoise: care

Like all living things, the Central Asian requires careful handling. Too often, it is not recommended to take her in your arms, as she may be under stress because of this, which will most likely lead to a decrease in activity and illnesses.

It is better for children to give a turtle only under strict supervision, because they can either drop it or injure it, and even worse - step on it.

Bathing. If there is no bath in the terrarium, it is necessary to bathe your pet in warm water at least once a week, immersing it in the neck for 15-30 minutes. Little turtles are bathed more often - 2-3 times a week.

You need to feed in a variety of ways: about 70% of the reptile's diet should consist of greens, about 25% - fruits, the rest - protein food, mineral and vitamin supplements. Turtles up to 2 years of age are fed as they are fed, but within reasonable limits, twice a day, every day. Adults are given food every other day.

• commercial turtle feed,
• berries (raspberries, strawberries, blackberries),
• vegetables and fruits,
• pre-harvested dried or frozen grass,
• leaves of fruit shrubs and trees
• garden snails and earthworms,
• lawn grass (dandelion, plantain, clover),
• some indoor plants (tradescantia, chlorophytum),
• special calcium supplements.

• black bread
• river snails,
• fish, meat, eggs,
• potatoes, cabbage,
• nuts,
• citrus peel,
• porridge and other products from your table,
• dry and canned animal feed,
• dairy products.

Give in limited quantities:

• grapes
• cucumber,
• onion, garlic, asparagus, spicy greens.

Gender differences

To distinguish a female from a male can be at 6 years of age on several grounds, and it is best to compare with several individuals at once.

Males of puberty are more aggressive in nature and, as a rule, always smaller in size. The abdominal part is concave. The tail, long and wide at the base, is slightly curved under the shell. Closer to the tail there is a dent on the plastron. The cloaca is located further.

The size of the female is always larger, their jaws are more developed. The abdominal part is flat. У основания короткого хвоста расположена клоака.

Breeding

Для разведения среднеазиатской черепахи понадобится пара — самец и самка — примерно одинакового веса и возраста. The sexual age of the female is 10-12 years, the male - from 5-6 years.

The mating period is February – August. The male comes up to the female and, pulling the head forward, begins to beat the shell with her in the side, while making a dull thundering sound.

Since males become more aggressive towards each other, it is not recommended to keep two males in one terrarium.

The pregnancy lasts 2 months. In laying from 2-6 eggs. Incubation lasts from 60 to 65 days at a temperature of 28-30 ° C.

The Central Asian tortoise overland is a beautiful and graceful animal in its own way, which requires affection, skillful handling and proper care. Having watched her, you will understand that behind her sluggishness lies the wisdom that many of us lack. Indeed, in constant haste we forget the main thing - to rejoice and enjoy life. Maybe this particular pet will make you think that it is worth stopping and looking at the world with completely different eyes.

How to care for a land turtle, look at the video:

Anatomical structure

Representatives of the detachment live in the steppes, foothills of Pakistan and India, in the deserts of Turkmenistan, Syria and Libya. As with other animals belonging to the family of reptiles, in the structure of their body, as well as in the processes of vital activity, one can find a number of idioadaptations to the dry and hot climate. Among these devices emit dense leathery integument, the absence of mucous glands, the presence of horny scales and scutes. These formations are composed of fibrillar proteins - keratins. Their function is to increase the mechanical strength of the outer covers.

Since land turtles, for example, steppe, Central Asian, feed on rather rigid vegetable food, they have a beak on their head, a peculiar process with sharp edges with teeth. They turtles tear off parts of plants and fray them lumpy protrusions. There are also eyes on the head. They are limited to three centuries: lower, upper and third. Presented in the form of a leathery film, covering the eye only half. All turtles have well developed binocular vision and are well oriented in the environment.

Skeleton turtles

To answer the question of whether the turtle has a skeleton, recall that the body of a reptile is divided anatomically into 4 parts. It consists of the head, neck, torso and tail. Consider the structure of the turtle in the cut. So, her spine consists of 5 sections: cervical, thoracic, lumbar, sacral and caudal. The skeleton of the head is completely bony. It is connected to the neck with two movable vertebrae. In total, the turtle has 8 cervical vertebrae. The head at the time of danger is drawn into the shell, due to the presence of holes in it. Land reptiles perceive sounds of low frequency. Turtles are referred to as "silent" animals, as their vocal cords are anatomically poorly developed. Therefore, they emit a hiss or squeak.

The structure and functions of the Karapaks

Continuing to study the skeleton of a turtle, consider the upper part of its shell. It has a bulge that looks like a small bell. In land turtles, it is especially tall and massive, in aquatic turtles it is flatter, streamlined. Carapax consists of two layers. The outer contains keratin scales - shields, and the bottom has a bone structure. Attached to it are the arches of the vertebrae of the lumbar-thoracic and rib. Coloring and drawing of the horny shields of karapaks are used by taxonomy to determine the species of animals. It is because of the tortoise shell that have been and remain the object of fishing. A frame for glasses, cases, and handles of knives are made from it. The shell has several holes in which the animal pulls in the head, limbs and tail at the moment of danger.

Plastron and its value

The lower part of the shell is called plastron. Between him and karapaksom is the soft body of the animal. Both halves are united by bone shell. Plastron itself is an anatomical derivative of the belt of the forelimbs and ribs. It is as if “soldered” into the body of a turtle. Ground forms have a massive plastron. And in marine life, it is reduced to cruciform plates located on the abdominal part of the body. On the plates of the shell, concentric lines are formed due to growth. According to them, herpetologists can determine the age of the tortoise and its state of health.

Characteristics of the skeleton of the belts of the front and hind legs of a turtle

The skeleton of a tortoise, which is shown below, indicates that animals of this species belong to reptiles. They have attached the bones of the girdle of the forelimbs to the spine: scapula, collarbone and crow formation. They are located in the middle of the chest. The scapula is connected to the carapace of the muscular fold at the location of the first vertebra. The hind limb girdle consists of pubic, iliac, and ischial bones. They form the pelvis. The tail section consists of many small vertebrae, so it is very mobile.

Features of the structure of limbs of land turtles

The forelimbs of reptiles consist of the shoulder, forearm, wrist, metacarpus, and phalanges of the fingers, which is similar to the skeleton of other classes of terrestrial vertebrates. However, there are differences in the structure of the bones of the forelimb. For example, the tubular bone of the shoulder is short, and their number, forming the wrist, is smaller than in mammals. The hind limbs also have anatomical features. The femur is very short, and their number in the foot is also reduced. This is especially noticeable in land turtles: box-shaped, red-eared, steppe. As they move along the surface of the earth, the bones of the phalanges of their fingers experience constant mechanical loads. Thus, the turtle's skeleton has the necessary idioadaptation, contributing to its adaptation to the habitat.

Pontoon: structure and characteristics of life

Among all other species, this animal is most popular as a domestic inhabitant. The structure of the tortoise red-eared typical of freshwater forms. Her head is well mobile, the neck is long, the shell is represented by green carapace, and the plastron is yellow. Because of this, the turtle is often called yellow-bellied. The limbs are massive, covered with horny shields, ending in claws. In nature, they feed on insects, larvae and fry of fish, as well as algae, living in abundance along the river banks. It is easy to distinguish the female from the male: it is more massive and longer, and its mandibles are larger. These animals breed from the end of February to May, laying from 4 to 10 eggs in the sand pits. Small turtles hatch usually in July or August.

Land Turtle Species

This group of reptiles is represented by such animals as the Central Asian tortoise listed in the Red Book, the Balkan, the Panther. There are only about 40 species. The outer skeleton of a turtle is a shell. It is very massive, with a highly raised plastron. The animals themselves are quite inactive. The Central Asian tortoise is little dependent on water sources. It can do for a long time without it, feeding on succulent leaves or sprouts of grassy plants. Since the animal has to adapt to the dry climate of steppe or semi-desert, its annual activity is strictly regulated. It is only 2-3 months old, and the rest of the year the tortoise spends half-stupor or hibernates in holes dug in the sand. This happens twice a year - in summer and in winter.

The structure of the land turtle is characterized by a number of adaptations associated with life on land. These are columnar massive limbs, the phalanges of the fingers completely fused, leaving short claws free. The body is covered with horny scales that prevent excessive evaporation and ensure the preservation of water in the tissues of the animal. Thus, animals are reliably protected by ultrastrong bone-horn shell. In addition, they can scare off potential enemies with harsh hissing sounds or a very fast emptying of a voluminous bladder. All species of land turtles are long-lived. They can live from 50 to 180 years. In addition, they are highly adaptable and resilient.

Nevertheless, let's not forget that 228 species of turtles are in need of protection and are on the verge of extinction. For example, the area of ​​the green turtle is rapidly decreasing. It serves as an object of fishing, as a person eats its meat. In connection with the urbanization and reduction of the area of ​​natural habitat, the number of animals is annually decreasing. The question of the expediency of keeping turtles in human dwellings remains controversial, even if they are localized in specially equipped conditions of the terrarium. An insignificant number of these animals live in captivity to their biological age. The majority perishes from the ignorant and irresponsible attitude towards them of a person.

Types and characteristics of land turtles

Systematics

The systematics of modern turtles is a difficult problem, since experts have not yet come to a common opinion on this issue. Today in the world about 220 species of turtles are recognized as valid. This is very small compared to, for example, snakes and lizards, the number of species that exceeds 7,000.
Some species are widely distributed, and throughout the area form many subspecies. According to modern concepts, the tiki system, the total number of living turtles exceeds 340 forms.

Biological features of land turtles

In this part of the book, the author would like to highlight some of the biological features of land turtles so that potential owners can better imagine what animals they have to deal with, what difficulties and why they may arise when they are kept.

Shell and musculature

Shell
The turtle shell is a bone formation and is covered with horny scales from above. It is divided into two sections: the upper carapace, and the lower plastron. The divisions are interconnected by bone bridge or connective ligament. Most often, both the carapax and the plastron are solid and immobile, but in some species, such as box turtles, the plastron can close, so that the turtle can completely hide inside the shell. This is due to the movably connected flaps of the plastron and is a mechanism for adapting to aggressive environmental conditions.

The turtle shell is easily injured and may be vulnerable to serious diseases, usually of a bacterial or fungal nature, which are most often the result of injuries. The condition of the shell must be closely monitored when kept in captivity. In the event of scuffs, cracks or damage from blows (for example, during mating tournaments), damaged areas must be treated. In the case of shallow injuries, drugs such as Betadine are suitable for this. If the injury is serious enough, with a break in the bone and penetration into the body cavity, then an urgent need to consult a doctor.

Musculature.
Even with superficial communication, you can see that turtles are very strong animals. Dealing with them is not so easy, even with relatively small specimens. Basically, they have developed musculature of the limbs and neck. This is due to their usual digging behavior and the overcoming of very large distances in the process of grazing. The muscles of the neck allow the turtle to pull its head deep inside the shell, which helps it to escape from predators. Trunk muscles are poorly developed due to the presence of shell. Nevertheless, it can play an important role in the closing turtles.

Internal structure
Digestive system. The turtles have no teeth. They are replaced by horny plates of ramp flow, which, being very hard, perfectly grind even very tough food. Turtles easily cope with hard chunks, for example, carrot chunks or hard plant stems.

Getting into the oral cavity, the food is enveloped in saliva and forms a food lump. Turtle saliva does not contain digestive enzymes; therefore, food that has not been swallowed for one reason or another may lie in the mouth or esophagus for weeks. This can be important if you need to force-feed your turtle. Forced feeding is carried out by probe directly into the stomach. It is better not to carry out this procedure yourself without consulting a specialist.

Directly in the oral cavity is a powerful tongue that helps push the food lump. He is not very mobile and is not able to move beyond the limits of the oral cavity. Its surface is covered with papillae, which are organs of taste. Not all types of turtles have these nipples, due to which many of them can eat stale, even rotting food.

For the oral cavity should pharynx and then the esophagus. The esophagus passes into the thick-walled stomach. Inside the stomach has a distinct folding, which is smoothed or even disappears completely during chronic gastritis.

The turtles have a large liver with a gall bladder, pancreas and spleen. In their functions, these organs are similar to similar organs of mammals; they secrete digestive enzymes and, together with the small intestine, carry out the absorption of nutrients.

The small intestine is relatively short, but in herbivorous Nida, it can be several times larger than in carnivorous. However, the structure of the intestines in those and others differs little. The main function of the small intestine is absorption of nutrients.

The large intestine has a much larger diameter. As it is from ruminant mammals, turtles do not have a special enzymatic cell for the breakdown of cellulose, this function is performed by the large intestine. It contains a variety of essential microorganisms that are involved in this process. That is why dysbacteriosis in turtles occurs quite often and leads to many serious diseases of the gastrointestinal tract. Coprophagy, which is common to so many turtles, is supposed to help regulate the level of essential bacteria in the intestines. This method is also often used in captivity for the treatment of dysbacteriosis.

A special feature of turtles is a strong increase in the time of passage of food through the gastrointestinal tract. When feeding on relatively gentle feeds (for example, green leaves) at a temperature of 28 - 30 ° C, digestion can occur within 7 days. When feeding more coarse feeds such as hay, this period increases to 2-3 weeks.

The speed of food digestion completely depends on the air temperature. At temperatures below 18-20 ° C, the rate of digestion is greatly reduced, and at temperatures in b-8 ° C, absorption completely stops.

Respiratory system.
The respiratory system of turtles consists of the trachea, bronchi and lungs. The entrance to the trachea is in the oral cavity at the base of the tongue. Usually it is closed and opened with the help of a special muscle during inhalation and exhalation. The trachea is rather short and is divided into two bronchi. The bronchi enter the lungs. Light turtles have a very large volume and occupy the entire upper body, closely adjacent to the carapax. The structure of light turtles is different from that of mammals, which allows them to function even with significant injuries, which primarily occur with damage to carapace.

It should be noted that due to the absence of a diaphragm, a real pulmonary pleura, ciliated epithelium in the trachea, turtles lack such phenomena as reflex coughing and sneezing. Only through special efforts can they carry out these actions. Since it is very difficult to remove accumulated exudate from the respiratory tract, turtles are very susceptible to various forms of pneumonia: mucus that forms in the mouth can leak into the trachea and cause inflammatory processes. Virtually any tortoise that is contained in inappropriate conditions and that is malnourished, at any time runs the risk of pneumonia.

Excretory system.
The excretory system of turtles consists of the kidneys, ureters, and bladder.
Kidney paired organ. They have a more primitive structure than mammals, for example, they lack the loop of Henle, and therefore they cannot concentrate urine. Water is mainly absorbed in the colon, bladder and cloaca. From the kidneys the ureters move away, which fall into the middle part of the urodeum cloaca. From here, urine enters the bladder by suction.

The bladder is quite large in size and is an outgrowth of the cloaca. The entrance to the bladder is delimited by the sphincter.
Since urine contains a lot of uric acid, after water absorption, it can be released in the form of white salts along with feces. Urine in the bladder can be "stored" for many days and even weeks, which, apparently, is an adaptation to arid environmental conditions.

The main diseases of the excretory system of turtles are associated with the presence of a large amount of uric acid. Uric acid itself is a fairly toxic product, among other things, poorly soluble in water and, therefore, poorly eliminated from the body. При повышении ее концентрации (гиперурикемии) она может выпадать в осадок в различных органах, прежде всего в почечных канальцах, что приводит к их закупорке. Это часто случается при сильном обезвоживании, в домашних условиях главным образом при содержании черепах на полу. Такое заболевание называется подагрой и полному вылечиванию обычно не подлежит.More information about gout will be discussed in the chapter on diseases of land turtles.

The reproductive system.
Females do not have a real uterus. Oviducts are paired and open into the body cavity with two funnels. Their beginning is in the middle of the cloaca (urodeum). Females have paired ovaries, and males have testes. Males also have an unpaired large genital located in the cloaca. When excited or while swimming, it may protrude beyond the limits of the cloaca. If kept on the floor, irreversible prolapse of the penis may occur as a result of strong dehydration and other factors.

In females during the reproductive period, the ovaries are greatly enlarged, large multiple follicles can be formed. Not only copulation, but also just the presence of a male or wintering, can stimulate this process. With inadequate maintenance, the risk of a pathological pregnancy increases many times over, which without the necessary veterinary care (usually surgical) but rarely results in the death of the animal.

Sense organs
Smell. The smell of turtles is very well developed. It is carried out by the olfactory epithelium, which is lined with a nasal chamber. To catch the smell of a turtle can not only nose, but also mouth, where there is also an olfactory organ. Therefore, when the tortoise suddenly begins to breathe heavily and often, it is most likely that at this moment it sniffs. Smells for turtles are an important factor not only when searching for feed, they are also orientation and signaling. Many turtles have odor glands that secrete a special secret in the event of stress. Also can sniff each other sexual partners.

With the occurrence of various diseases, such as rhinitis, stomatitis, pneumonia, olfactory ability is greatly reduced.

Vision. The turtles have excellent color vision. This explains the fact that turtles react to the color of the food they choose. Often this factor plays an important role in choosing a sexual partner. In general, they perfectly analyze the peculiarities of the environment with the help of this sensory organ and can refuse to feed and feel general malaise for eye diseases.

The structure of the eye of turtles is quite characteristic of vertebrates; we will not dwell on this in detail. The eye is covered by the upper and lower eyelids, as well as by the flashing membrane of the third century, and the cocotric is located under the first two. Unlike mammals, turtles move not the upper, but the lower eyelid. There are guardian and lacrimal glands.
Under normal condition, the animal's eyes should be dry and clean, without any discharge. Eyelids should open freely. With frequent swelling of the eyelids
open badly, only a small gap. This creates a great turtle discomfort.

The condition of the eyes of the turtle must be carefully monitored and with a first alarming symptoms, consult a doctor.

Hearing. The inner ear of turtles has a structure typical of terrestrial vertebrates. They have a tympanic membrane, delimited from the external environment by the tympanic shield. These shields are clearly visible on the sides of the head of the turtles. Most often, this shield is quite dense, which explains the ability of turtles to hear mostly low sounds (150,600 Hz).
Therefore, they are best distinguished by sounds such as knock, rustling, footsteps, etc. The sound of the human voice, the music, they distinguish much worse.

Here we only briefly focused on the physiological features of the turtles. Currently, there are other works in Russian, in which their physiology and biological features are covered in much more detail. We would like to give only a general idea of ​​these animals, the important thing from the point of view of communication between the owner and the pet.