Snakes - types and titles. Common characteristics of snake characteristic signs of snakes

Snakes are one of the most peculiar creatures on Earth. Their unusual appearance, the original way of movement, many wonderful features of behavior, finally, the poisonism of many species - all this has long been attracting attention and causes live interest in humans. A variety of legends, fairy tales and myths about snakes are folded in various peoples of the globe. All these fantasies, reinforced by sometimes unrecoverable superstitious fear of snakes, so closely twisted with the actual facts that many "truthful" stories about snakes are much fantastic than any myths. Studying snakes gradually exposes legends and at the same time opens up new wonderful features in the structure and lifestyle of these animals.

At first glance it seems that snakes are easily distinguished by appearance from all other reptiles. Indeed, they have a long, deprived of the torso torso, dressed with scales, their eyes are always covered with a transparent leathery, they have no outdoor ear. However, all these features of the structure can also meet with various lizards. Lizards and snakes are nearby animals, so they are only attributed to different suburbs inside the general detachment of scaly (Squamata).

About thirty signs of external and inner structure distinguishes snakes from lizards, but almost all of them "as an exception" are found in the latter. Thus, only the complex of all these differences can be reliably divided by two suburbs of scaly reptiles.

Skull Snake has the most characteristic and sustainable signs of these animals that distinguish them from lizards. The structure of the skull ensures the exclusive tensileness of the mouth of the snake, which allows them to collect entirely prey, which is much thicker than their body.

The bones of the facial part of the skull of most types of snakes are movably interconnected, and the lower jaw is suspended to the skull on highly tensile ligaments. The elastic bunch also connects the right and left half of the lower jaw. In addition, the brain of snakes is entirely concluded in the bone capsule, and the inter-client partition is not developed.

Snake's teeth are well developed and serve to bite, capture the extraction and pushing it into the esophagus, but not for chewing or tearing extraction, since the victim swallows entirely. Therefore, all the teeth are relatively thin sharp and bent back. They are located on the upper and lower jaws, and in many snakes also on the roaming, wonderland and intercelion bones. In addition to conventional solid teeth, the serpent of some families have furillary or tubular teeth that serve to introduce poison to the body of the victim. Frozen teeth located in the back of the upper jaw are characteristic of poisonous snakes. Aspident and sea snakes have short fixed tubular teeth in the front of the mouth, and the pulmonary and ompologists are long and movable tubular teeth, fortified on a very short maxillary bone, which can rotate. At the same time, divergent fangs when closed, the mouth lay along the jaw, the edge back when the mouth opens, they become perpendicular, taking a "combat" position.

The belt of the front limbs in the snake is completely absent, and on some snakes belt (fluffs, rolling snakes, shames, narcot snakes) are preserved small bone pelvis rudiments. Rudiments themselves are also preserved at the boots and riveted snakes in the form of paired curls on the sides of the anal hole.

The spine snakes due to the disappearance of the limb belts is unclearly divided into departments. The number of vertebrae is very large, from 141 in the thick and short snakes up to 435 in the longest and thin. Ribs have exceptional mobility. There is no primer, and therefore ribs can widely disperse, passing large prey on the digestive tract. In addition, many snakes are able to breed on the edges of the rib, which concludes the body, during defense.

The internal organs were significantly changed in accordance with the elongated form of a non-lawy body. All of them have an elongated shape and are asymmetrically located. In addition, some of the paired organs have lost one half and became unpaired. For example, both primitive snakes are developed both lungs, but the right left is always more left; Most snakes left lightly completely disappear. Wavyuki and some other snakes, in addition to the right lung, have also the so-called "tracheal light", formed by an extended back of the trachea, the very light in its back is transformed into a thin-walled air tank. He is very tightened, and the snake can be very swelling when inhaling, and when exhaling, it can make a loud and long hiss.

Serpent's esophagus is a very muscular, which facilitates the pushing of food in the stomach, which is an elongated bag, passing into a relatively short intestine. The kidneys are strongly pulled in length, and there is no bladder. The seeds are also elongated, the kopulatory organ of males is paired bags, usually equipped with various and shaped siebs. These bags lie under the skin behind the anal hole and turn outwardly when excited.

For the nervous system, snakes is characterized by a small head and powerful, long spinal cord. This causes, on the one hand, the primitiveness of higher nervous activity and, on the other - high coordination, accuracy and reactivity of the muscles of the body.

The most important organ of feelings of snake is a language in combination with the Jacobson authority. The jacobson pair body is a subtle chemical analyzer and has two outlet openings on the top noble. The snake language is supervised through the semicircular cutting of the upper jaw, a few seconds trembles in the air, slightly touching the twisted tips of nearby objects, and then draws inside. Here, the ends of the tongue are shoved into the holes of the Jacobson organ, and the snake receives information about insignificant quantities ("tracks") of substances in the air and on the substrate. Thus, alternately proving and removing the language, the snake quickly and confidently moves along the trail of prey, looking for sacrifice, partner or water source.

Unfortunately, many people still think so far; Snake language "deadly sting" and, having seen his torn tips, confidently declare a snake of a poisonous and a completely harmless animal is killed at every opportunity.

Eyes also play a major role in the orientation of snakes, but most vision does not differ in sharpness. This, in particular, is due to the fact that the eyes are covered with a thin and transparent lean film formed from the thorough eyelids. This film comes out with the eye with the rest of the hopper during a molting. Therefore, in front of the stem, the snakes are muttered (the surface layer of the film is peeled), and after molting become especially transparent. The dry film, covering the eye, gives the sight of the serpent seeming immobility and coldness, which so scares many people and creates myths about the hypnotic power of a snake view. The pupil of the eye in the day snakes is round, and the twilight and nights are often stretched into the vertical gap. It has a special form of punching snakes, most of all resembling a horizontally located keyhole. This structure of the pupil provides the ability to binocular vision, at which up to 45 ° field of the review covers in two eyes at once.

Snake smell is well developed and serves as one of the leadership feelings. Nostrils are located on the side or upper edge of the muzzle. At sea, as well as in some sandy snakes, nostrils can be closed by special valves, which protects against water in diving or sand when crawling in its thicker.

Hearing organs are strongly weakened: there is no external hearing aid at all, and the average ear is also simplified. Only the inner ear is fully developed. Therefore, snakes very badly hear sounds spreading through the air, and in the usual sense they are almost deaf.

Some snakes found the thermal feeling organs, or remote thermistors, allowing them to capture the heat outgoing from the body of mining. Pythonov is represented by shallow pits on the topless panels, in African violence of the birth of the Bitis, they have a view of a bowl-shaped deepening immediately behind the nostrils. Especially high development reaches these bodies at the jammer snakes. The pair thermoloctor is visible outside in the shape of a hole on the sides of the muzzle between the nostrils and the eye.

Snake's body dressed with horny shields and scales. On the head, many snakes, large scrolls of the correct and constant form are grouped in strict; A typical order for each type, and serve as an important feature for the scientific description and determination of species.

The torso from above and from the sides are covered with a rugged-shaped scales, which is located longitudinal and diagonal rows, and usually the front scales are slightly lifted to the rear. In some types of scales can have a hexagonal or triangular shape and placed in the same plane, without lifting (some sea and wart snakes). Horny scales are smooth or have a more or less pronounced longitudinal keel. Between the horny scales of neighboring longitudinal rows there are areas of thin and soft leather, assembled into a small fold, hidden under scales. When swallowing large mining, the longitudinal ranks of the horny scales are diverged, the leathery folds are spreading and the body increases greatly in the diameter. The scales of one longitudinal series, on the contrary, are firmly connected to each other.

Belo snakes are covered with large cross-stretched shields. Only in some aquatic and digging species (warthogs, part of the sea, shapshmes, the narrowed) body from the bottom, as from above, is dressed in small scales. Abdominal shields are connected to the soft folds of the skin, and when swallowing large food, these folds are spread, and the abdominal shields diverge in the longitudinal direction. Thus, the coverings of the snakes have greater extensibility, and on the back and sides - transverse, and on the belly - longitudinal.

The top layer of the skin is periodically peeling, and molting occurs. With a molt, the epidermis extended at first in the front end of the muzzle, and then the stocking removes the snake body. A melting snake is actively moving, rubs his head about the soil and stones, breaks up in a gap, painting an old skin with himself. Before the stink of the coloring of the snake becomes whitish, and the eyes are aimless, but after the molting snake sparkles with bright fresh paints. Healthy snakes are linked 2-4 times a year, and quenching is entirely, and in patients and depleted snakes molting occurs more often and the old skin is peeling with pieces.

In the rattling snakes during a molt, the end scales remain on the tail in the form of caps and form a special ratchet, which is used to prevent major enemies.

Snake coloring is very diverse and mostly adaptable to the color of the natural situation. Such is the green color of many tree snakes, yellowish-sandy - in desert species. The color of some species, such as Tiger Python or Gabon Vijuki, seems to us bright and striking when we see them in the zoo. But in natural conditions, among the motley sheets under the canopy of the rainforest, this coloring perfectly hides the snake, dismembering and making the true contours of her body invisible.

Some species, however, have a bright color that allocates them even in a natural environment. These are primarily coral and garter aspids, the royal snakes, in the color of which alternate black, yellow and red transverse rings. This coloring warning. The emergency similarity of non-team royal snakes and poisonous aspids often lead as an example of intelligent similarity - mimicry. However, such an explanation does not withstand critics: first, coral aspids are very rare and reluctant to bite and lead a twilight lifestyle, so that predators cannot work out a clear idea of \u200b\u200bthe danger of this color; Secondly, the alleged "imitatives" - the royal snakes are much wider than their imaginary "model".

Many snakes painted by patronishly have a body area with a bright pattern, which they demonstrate only at the time of danger. Such is the pool snake - a cobra, painting the neck department with a clear drawing of "points" on the dorsal side. In other types of snakes, the lower side of the tail is painted in a bright orange color, and during the defense of the snake raises the tail with a bright side to the enemy and shakes them, sometimes even makes the "lunges" of the tail, as if wishing to bite.

Usually, young snakes are painted more bright and contrast, and adults are more monophonic.

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Why are these animals called reptiles?

The limbs of reptiles are attached on the sides of the body, widely placed. Therefore, when moving, the body saves and concerns the Earth (reptiles).

Which of them live in your area?

In the central region of Russia, Vauduk dares, a hunted lizard, a steppe turtle.

Questions

1. What are the acquired features of the structure allowed the reptile fully to go to the ground lifestyle?

Skip to the terrestrial lifestyle reptile allowed the dry surfaces of the body, buried top, cellular lungs, internal fertilization. The structure of the skeleton reptile allowed them to move faster, to carry out the turns of the head, which is also important in life in the ground medium.

2. What are the characteristic features of snakes?

Snakes do not have limbs. Move, flexing the body, due to powerful muscles and numerous ribs whose ends appear through the skin. Asimes, the animal clings for soil irregularities. Unlike lizards, the snakes have a non-moving look, since their eyes are covered with transparent controversial centuries. Snakes are capable of "stocking" for mining thanks to the spreading rolling jaws. Snakes are poorly seen. The split tongue in the snake is the organ of touch, smell, taste. Poisonous snakes have poisonous teeth.

3. What functions perform a serpent split at the end?

Snake language performs functions of touch, smell, taste.

4. What animals belong to the detachment of scaly? What is their meaning in nature and human life?

The scaly detachment includes lizards, varana, snakes. Most lizards and snakes, entering insects, rodents and terrestrial mollusks, harmful to agriculture, bring a person benefit. In some countries of South America, South Asia and Africa, unite correspondents hold instead of cats. In nature, reptiles exist in the overall nutritional system: some eating plants, other animals (insects, amphibians, reptiles, small animals), and they, in turn, eat other predators - predatory birds and animals.

Danced the bites of poisonous snakes. However, the study of the action of serpentine poisons made it possible to create valuable medical preparations on them, which are used in the treatment of diseases of the respiratory organs, hearts, joints. Large snakes are extracted to obtain beautiful and durable skin. Among reptiles have vegetal and insectivorous species. Most are predators. Singing plants, insects, amphibians, small animals, reptiles regulate their number.

5. In connection with which the reproduction and development of reptiles consider more progressive than that of amphibians?

Fertilization in reptiles internal. The seed fluid enters the sexy paths of the female when the closac of the male and females. The embryo in the fertilized egg develops already when the egg is moving along the ovage, is covered with egg shells. They provide germs with water, protect against damage and concussions. Sometimes young develops in the body of the mother. In these cases, eggmifting occurs. For example, Vijuki and a nippleny young lizard hatching out of the egg during his postponement. The eggs reptiles are equipped with a sufficient nutrient nutrient. From eggs are hatched full-fledged individuals, not larvae.

Tasks

Relying on the knowledge gained in the course of the Obzh, name the first medical care measures for snake bite.

Snake bite: first aid

It is necessary to immediately put the victim and ensure full peace, since any movement enhances blood circulation, which means that the penetration of poison in the body.

In the first few minutes, you need to reveal the wound with pressure and start sucking the poison, regularly flatly spitting it. Do it for 15 minutes. Do not be afraid to choose: sucking poison from the wound - a completely unfulfought procedure. Just do not swallow the poison.

Disinfect the wound with any disinfection tool at hand - iodine, alcohol, green.

Take a sterile bandage to the affected place, which as the limb will be loosened.

Give the victim to drink and deliver it to the medical institution as soon as possible.

If you notice that the victim fell into shock, try to withdraw it from this state. If he stops breathing, begin to make it an artificial respiration.

If the victim loses consciousness, but his breath is not interrupted, turn it over his chest and put in a pose, safe for breathing.

Apply on the affected limb harness.

Cut, catch and generally injure the wound from the bite.

Felt the wreck of a hot metal, matches, manganese powder, etc. - it also damages fabrics.

To give the affected alcohol: the nervous system will only react to the poison, which is also stronger in the body.

Find out what reptiles are subject to protection in your area?

Reptiles of the Red Book of the Moscow Region: Lizard Jumping, Sparkling Spicy, Ordinary, Median, Ordinary Viper.

Think and discuss with classmates, why a snake is depicted on the medical emblem?

The origin of the medical emblem - bowls, accruiling a snake, is lost in ancient times. For many centuries, medicine has had many different emblems, but this image got the greatest distribution. The image of the snake has long been attached the attention of people. In a primitive society, during the matriarchate, when there was a cult of animals, the snake was considered sacred, and in the ancient world she personified power, wisdom, knowledge, as evidenced by the folklore of the peoples of all continents. Ancient legends attribute to snakes the ability to understand the conversation of herbs and recognize their healing force. In many fairy tales of different peoples, the snake was considered a symbol of wisdom, who took the snake meat, said in them, acquires the gift of clairvoyance.

In the most ancient images of the medical emblem, the snake appears without a bowl. The bowl appeared later. She symbolized the birth of life, the life itself, the protection of life and the struggle for life. Diseases in antiquity were treated with water, herbs and products of animal origin. The bowl acted as an object that had magical healing force symbolized the presence of a good healing start. In the slaveholding states, the bowl played a major role in ritual sacrifices. In ancient Egypt, the ancient Greece bowl symbolized the protection of health and approval of life. In antique mythology from the bowl of the gods drank a drink of immortality.

Initially, the bowl and snake were depicted separately, then at the beginning of the XVII century were connected together.

In the modern medical emblem, the snake personifies wisdom, knowledge, immortality, and the bowl of the vessel for the medicinal poison. In the emblem, the leading place: belongs to the snake, and the bowl has an additional value and cannot serve separately emblem the medicine.

Snakes are reptiles! More specifically, they are classified as animal representatives; a type ; Class. There are several supersatimities, families, childbirth and more than 3.5 thousand site species. Reptiles also include turtles, crocodiles, beakheads, amphisben and lizards.

Reptiles -, which means that their body temperature varies depending on the environmental conditions. They warm in the sun to raise the temperature of their body or hide in the shade and under the stones to reduce the temperature.

Today, more than 3.5 thousand types of snakes are known to science. They can be found in, streams, and. They can live in water, on land and on top of trees. Snakes are found at all (except and isolated islands, such as New Zealand and Ireland).

Body snake

Snakes have elongated cylindrical bodies covered with scales, which act as a protective armor against solid and hot surfaces when driving. Scales is also waterproof and prevents moisture loss. Scales on the stomach allow snakes to move along smooth surfaces and cling to the branches. Snake need molting and dump the old skin at least once a year. When the snakes are going to reset the skin, their eyes become muddy and partially blind.

Snake has bones?

Many people think that these have no bones because of their ability to bend the body. However, the serpent has more bones than people. While the adult has about 33 vertebrae and 24 ribs, snakes have more than 200 vertebrae and as many ribs. Their bones are short and slender, which is the cause of their flexibility. They have strong muscles that protect internal organs. The head and throat make up a third of the number of all bones in the body. Snakes have two large lungs, intestines, kidneys and a long liver.

Fang Snake

Most snakes have teeth, two rows on the lower jaw and four rows from above. However, only poisonous snakes have fangs. Fangs are sharp, long and hollow teeth in the upper jaw. They are attached to poisonous bags in the snake head and are used to highlight poison. The poison kills or paralyzes prey. Also, poison is often used for the manufacture of an antidote.

Question 1. What are the acquired features of the structure allowed the reptile completely to turn to the ground lifestyle?

Adaptations reptiles to a terrestrial lifestyle:

1) the delicate of skin and the lack of glands that would moist the skin, which is associated with water saving, evaporation protection;

2) pulmonary respiration, which ensures oxygen from the atmosphere;

3) osenation and development of the skeleton (especially the cervical and thoracic spine, free limbs and their belts) and the muscular system, which allows you to actively move in less dense than water, ground-air environment;

4) Internal fertilization, laying of fertilized eggs with a large reserve of nutrients coated with protective shells, which gives complete independence from the aqueous medium in reproduction.

Question 2. What are the characteristic features of snakes?

Snake no free limbs. They developed a special mechanism of movement by side bends of the spine and ribs. Snakes weakly see and hear badly. There is no outer auditory hole. The eyes are hidden under a transparent leathery formed by the controversial centuries (non-moving look). In poisonous snakes in the upper jaw there are two particularly distinguished poisonous tooth. The poison is produced by paired poisonous glands, located on both sides of the head behind the eyes. Thes of them are connected to poisonous teeth.

All snakes are predators. They are able to harvest prey, many times superior to the thickness of their body. This is facilitated by special jaw joints. The lower jaw is movably connected to the bones of the skull and is able to move forward and go back as on the hinge. Its halves are connected on the chin flexible ligament and can be moved to the sides.

QUESTION 3. What functions perform the serpent split at the end?

Snake language is the organ of touch, smell, taste. Through a semicircular hole on the upper jaw, the language can be aligned with the closed grazing. Supervising and removing the language, the snake receives information about the smells in the air, and when touched by the language to the surrounding items - about their surface, form and taste.

Question 4. What is the meaning of scaly in the nature and life of a person?

Most scaly reptiles are predators or insectivorous animals. Many types of snakes feed on rodents, carrying out the regulation of their number in nature.

Poisonous snakes can be dangerous to human life and health, but only in case of its careless or inattentive behavior. The poison of some snakes (for example, the points of the snake - cobra) is very valuable, various drugs produce from it.

Question 5. In connection with which the reproduction and development of the reptiles are considered more progressive than that of amphibians?

The appearance of reptile inner fertilization and egg shells is an essential adaptation to a terrestrial lifestyle and a progressive sign, respectively. Most of their representatives breed by laying eggs covered with a leathery shell (in lizards and snakes) or limestone shells (in crocodiles and turtles), but there is also a so-called eggsiveness, in the course of which the yield out of eggs (the release of them from egg shells) occurs in Mother's body. The eggsiveness is typical for species of reptiles living in a temperate climatic zone (many lizards, ordinary viper, some of the tags), or those that have moved to a fully water lifestyle (sea snakes).

There are many amazing living beings on our planet. We see some of them every day, passing down the street, we can only meet others in the wild or zoo, and we do not notice the third and not at all. Among other living beings, a decent place is occupied by snakes. These amazing creatures have a number of unique features with them, many legends and legends are associated with them. In addition, some of their species are very useful for a person.

general information

Snakes Biologists refer to scaly, or rather to the sublit of reptiles. The snake sounds in Latin - Serpentes. This species can be found almost in any corner of the world, with the exception, perhaps the Northern and South Pole, as well as a number of islands. The largest, of which are New Zealand and Ireland.

Despite the fact that the snake is habitually associated with poison, the number of non-poisonous types of snakes exceeds the number of their poisonous fellow. Poison is a tool helping many snakes in the hunt. There are a number of species of these creatures whose poison is able to kill a person. Snakes devoid of this tool for hunting, or swallow foods live, or suffer it, or strike a strong head, a prolaming skull of the victim.

The smallest representatives of this type of reptiles have a length of about 10 cm. And the largest of the officially registered has a length of about 15 meters. Moreover, according to scientists, this is not the limit and in the jungle Amazon can be found and larger individuals. On average, most snakes have a length of about one meter. In the wild, the snake lives 5 - 15 years.

Snake's body, its features

Visually can be confused with anent lizards and snakes. But looking easily can be distinguished by these creatures. And the left and right pieces of jaws in the snake are moving, they do not have ear holes and drummers, as well as a shoulder belt. In addition, the snake does not have a century.

Her body is covered with scales, to the touch, despite a variety of delusions, it is dry. In fact, the snake has transparent scales - centuries that are closed all the time. They protect the eyeball, allowing a snake to see through themselves. The snake periodically lines, dropping the old skin.

The body of the snake is elongated, the internal organs are located in connection with this in different parts of a very long body. The snake has no chest, most of her species do not have bones of the pelvis. Although some species still meet his rudiment. Skull Snakes has not only a special form, but also a specific structure, in particular, most of its bones, very moving relative to each other. Many of them are associated with special bundles.

Poisonous snakes have special bags with poison and sharp teeth through which the poison comes on them on special channels or grooves. The features of the structure of the internal organs of these creatures can be listed for a very long time. We only note that a number of species may have minor differences.

Sense organs

• It is worth paying special attention to the senses. They have such feelings:
• Smell. In order to catch the smell of the mining of the snake use not nose, but language. He collects particles of smells and transmits them into the oral cavity, where the special organ analyzes them. The language, thus, performs simultaneously by the body to determine the taste and smell.
• Vision. Different types of these reptiles have very different visual sharpness. Some distinguish only light and darkness. While the vision of others is very acute. Often, weak vision have snakes living under the ground, and good dignity of the inhabitants of trees. In many species of these creatures, the vision serves primarily to track movement, and not to obtain a clear image.
• Heavy sensitivity. On the head, snake there are a number of special thermal receptors. They provide an opportunity for these reptiles to fix the heat that radiates warm-blooded animals. It resembles a kind of thermal vision.
• Vibration sensitivity. In return, the snakes got the opportunity to feel the sounds and vibration of the Earth. Due to the high sensitivity to vibration, these creatures feel perfectly when other animals or other objects are approaching them.