Horde overall characteristics and features. Chordovy - these are animals, distinguished by complex structure and diversity

Chordan animals include about 40 thousand different types of individuals different from others in structure, lifestyle, habitat.

Era Paleozoic contributed to the emergence of this type of animals about 500 million years ago. Scientists suggest that their progenitors were ringed worms.

The chords were settled throughout the planet and became the usual inhabitants of the sea, sushi, air and even soil.

What is chord and who are so chord

The inner structure of chord animals is different from others. It is characteristic of the presence of an axial skeleton - a spinal column, which otherwise is called like chord.

It is this feature of the structure of the spine gave the name of the chordan animals.

Features of the structure

For chordan animals, the following features are characterized:

1. The location of the nervous tube above the axial skeleton and the formation of the spinal cord.
2. The presence of a rod is chords.
3. No intestines in the tail department.
4. Heart location under the digestive tract.

Chordata type (Chordata) - examples of animals

Representatives of chordan animals:

Origin and evolution of chord

Biology as science considers the origin of the chords one of the most important stages of the development of the historical world of animals.

The emergence of this type meant the emergence of new animals with a unique structure, which allowed them to further evolve to creatures with maximum complexity in structure and behavior.

Some scientists believe that the chords began to exist before the occurrence of ringed worms that were fed by filtration. Other scientists refer them to the ancestors of the chord.

One way or another, but the evolution of ring worms or, as they are also called, bottom-in-law animals, gave rise to new types: needle-roofing, poles, semi-ferrous and chord.

In the future, the chords evolved in three directions depending on the lifestyle:

1. The habitat of the first direction of the first direction was the solid ground. This contributed to the active development of the filter apparatus, providing food with a low-lifting lifestyle, and the formation of a thick protective shell on the entire surface of the body. These individuals have an ability to disperse. So the shells appeared.
2. The habitat of the individual parties is the bottom. They moved a little more, driving into the ground. Such a lifestyle simplified their original organization. The development of the Mochortodal complex required an increase in mobility, and the growth of the pharynx added new gill gaps. This branch has been preserved to this day in the form of undetective.
3. The habitat of the third-destination individuals who began to conduct a floating lifestyle - fresh water. There was a transition to active nutrition, high mobility. The nervous system and sense organs have become more perfect, which led to the complication of the behavior and the emergence of more complex forms. So there appeared a group of vertebrate animals.

In rivers and other fresh waters, the same unlimited, which were later ordered by jewish. They expanded the habitat to salt water and became the progenitors of modern fish groups.

Later from fish separated amphibians. Then they went to the land, and thus a new species appeared - reptiles.

General characteristic of the type chord

Pokrov consists of two-layer skin. The upper layer is represented by the epidermis and its derivatives: scales, feathers, wool, hair. In this layer of the skin there are odorous glands producing mucus and sweat. The bottom layer is a dermis consisting of fibrous connective tissue.

The musculoskeletal system is represented as a skeleton consisting of chord and connecting the shell tissue. The skeleton of the head shares onto the brain and the facial part.

The fish appear the jaws, and the vertebrates develop two pairs of limbs. Bones are connected using joints.

The respiratory system at the lower chords is represented by the gills, and the vertebrates are light. In addition, the skin of the chords is partially engaged in gas exchange.

The digestive system in cerebidoids is a straight tube and almost undeveloped digestive glands. Vertebrate is a digestive channel that has sections.

First, food goes into the mouth of the cavity, then passes into the throat, begins to be processed in the esophagus, passes into the stomach and, in the end, falls into the intestine. In addition to the listed organs, the vertebrate has a liver and pancreas.

The blood circuit is closed. Vertebrates, due to an increase in the intensity of metabolism, the heart appeared and complicated. There is no brave heart.

In the birds, the heart differs from the heart of reptiles only by the presence of a complete partition and the absence of the left arc of aorta; In mammals, a four-chamber heart swinging two types of blood: arterial and venous.

The central nervous system (CNS) of the chords has the appearance of a nervous tube with an inner channel, which for vertebrates forms a brain. The peripheral nervous system includes brain and spinal nerves departing from the central nervous system.

The excretory system in all chordines, except for lancing, is represented by paired kidneys, ureters and bladder.

Sexual system: reproduction occurs with the help of seeds in males and ovaries in females. Shells are hermaphrodites, they multiply in sex and useful ways. The remaining chords have sexual division.

Classification of chordovy and their subtypes

Chordovy are divided into the lower (Midhog, Lantern, Mixin) and the highest (reptiles, amphibians, fish, birds, mammals).

Allocate the following subtypes:

• undecented;
• shells;
• concentrate;
• primary: fish classes;
• four-legged: classes of amphibians or amphibians, reptiles or reptiles, birds, mammals.

What signs of chordovy have a person

In humans, like chordov, in the early stages of development, the formation of an axial skeleton occurs, i.e. chords. The musculoskeletal system in humans is presented, as in vertebrate animals, a supporting inner skeleton.

A person also has the following signs of chordan animals:

• central nervous system, which has a tubular structure;
• a closed circulatory system with the main blood circulation organ - with a heart;
• the breathing apparatus capable of communicating with the external environment through the pharynx, the cavity of the nose and mouth.

Monkey eel

Some curious information:

The value of chordan animals is very large, they are related to the most diverse and numerous types. At the moment there are about 50 thousand species of chordovy. The presence of a common feature in all individuals - chords (support authority) gave the name to this type of animals.

Anatomical signs of chord animals are similar to iglozzy. Lower representatives of the chordovy - lancing, who preserves their main sign throughout life.

The type of chordata (Chordata) has a number of features:

I. The presence of an internal axial skeleton (chord). Chord performs a reference function. Second function - movement. Chords during the life remains only at the lower representatives of the type. At the highest chord, it is laid in embryogenesis, then replaced by the spine, which is formed in its connective tissue shell. Chord is formed from Entoderma.

II. The central nervous system (CNS) is represented by the nervous tube. In the process of embryogenesis in the ectoderma, the nerve plate (the stage of neuroul) is laid, which is then folded into the tube. A spinal cord is formed with a cavity (neurotic or a spinal channel) inside. The cavity is filled with liquid. At the highest chord, the front department of the nervous tube is differentiated into the brain. The biological significance of this type of structure of the CNS is that the nutrition is nervous occurs not only from the surface, but also from the inside, through the cerebrospinal fluid.

III. The front department of the digestive system (s) is permeated with gill slots. Gwee gaps are holes that connect a throat with an external environment. They arise as a filtration unit for nutrition, but they combine the respiratory function. The vertebrates at the gill slots are breathing organs - Zhabra. Ground vertebrates have only in early stages of embryonic development.

IV. Chordovy possess bilateral (bilateral) symmetry. This type of symmetry is characteristic of most types of multicellular animals.

V. Chordovy - secondary animals.

Vi. Chordovy - reserved animals, together with semi-ferrous, iglozzy and pursuit. In contrast to the primary, the mouth breaks down again, and the anal hole corresponds to blasopra.

VII. The plan of the chordine structure is determined by a strictly natural arrangement of the main organs of organs. The nervous tube is over chord, the intestine is located under chord. The mouth opens at the front end of the head, and the anal hole at the rear end of the body - before the base of the tail department. In the abdominal part of the body cavity there is a heart, blood from the heart moves forward.

Subtype of shells (Tunicata)

Shells - a peculiar group of marine organisms, in the structure of which the complete set of morphological traits inherent in chord, is not detected; They can be solitary, can form colonies. There are planktonal forms and forms, leading attached lifestyle. Before the works of A. O. Kovalevsky, who studied ontogenesis of shells, were attributed to the invertebrate animals. A. O. Kovalevsky proved that it is undoubtedly chord, and the primitiveness of their structure is due to a fixed or larger way of life. The subtype is divided into three classes - ascidics, salmps and appendiculory.

Ascidia class (Ascidiae)

Externally, the ascages have a bag shape, fixedly attached to the substrate. On the spinal side of the body there are two siphons: the mouth of the siphon, the intestines are sucked through it, and the clock siphon is out of it outwards. According to the type of cape - filtrators.

The body wall is formed by mantle, which consists of a single-layer epithelium and layers of transverse and longitudinal muscles. Outside there is a tunic, which is distinguished cells of the epithelium. Musculature reductions provide water current through siphons. The flow of water contributes to the fixed epithelium of the oral siphon. At the bottom of the o'clock siphon, there is a river hole surrounded by tentacles.

The mouth leads to a bag-shaped sip, permeated with many gill holes. Under the epithelium of the pharynx is blood capillaries, in which gas exchange occurs. The throat performs two functions - respiration and filtering of food particles. Food suspension settles on the mucus allocated by special formation - endostile. Then mucus together with food, due to the work of the ciliary epithelium, falls into the esophagus, and then in the stomach, where digested. The stomach moves into the intestine, which opens the anal hole near the clock siphon.

The nervous system is formed by the spinal ganglia, from which the nerves go to the internal organs.

The circulatory system is not closed. There is a heart. From the heart, blood moves along the vessels and is poured into the lacuna between the internal organs.

The excretory system is represented by the kidneys of accumulation - peculiar cells that absorb metabolites - uric acid crystals.

Ascidates can multiply both nonsense (boring) and sexually. As a result of the kinding, colonies of astzdia are formed. Ascidia (like other shells) - hermaphrodites, fertilization outdoor, cross. From fertilized eggs develop larvae, actively floating in the thickness of water.

The larva consists of a torso and tail and has all signs of chord animals: in the tail is chord, the nervous tube above it, in the forefront of which there is an equilibrium organ and primitive eye. The throat is equipped with gill slots. Setes the larva at the bottom of the front end. Further conversion of the larva is an example of a regressive metamorphosis: the tail disappears, and with it the chord, the nervous tube turns into a dense nervous ganglion, the throat increases in volume. The larva serves for resettlement.

Salp Class (Salpae)

According to the structure and peculiarities of life, ascdias are reminded, but, unlike them, they lead a plankton lifestyle. Most Salp are colonial organisms. For these animals, the natural alternation of sexual and crucible reproduction (metagenesis) is characterized. From fertilized eggs, culls are formed, which multiply only the kiliation, and the individuals resulting from the useless reproduction, proceed to sexual reproduction. This is the only example of metagenesis in chordan animals.

Class of Apandicular (Appendiculariae)

Wear a free plankton lifestyle. The body is divided into a torso and tail. Internal organs are in the torso. Gill slots open to an external environment. Nervous gangliy is located on the dorsal side, from which a nervous trunk goes back to the tail. Chord is in the tail. Outdoor epithelium appendiculory forms a mucous house. In the front of the house there is a hole from thick mucous threads, and a smaller diameter hole is located in the back of the house. With the tail of the animal makes water current in the house. Small organisms pass through the grille of the inlet and glued to the mucous threads forming the "Cull Network". Then the network with nanileous food is drawn into the oral hole. Water leaving the rear hole of the house promotes the reactive movement of the animal forward. Appendacularities from time to time destroy their house and build a new one.

Appendaculararies multiply only sexually, development proceeds without metamorphosis. Fertilization occurs in the ovaries of the maternal individual, from where the young animals go through the walls of the mother of the mother's organism. As a result, the maternal organism dies. Perhaps appendicularity is an example of the last, that is, reproduction at the larch stage.

Subtype Umbers (Acrania)

Unthable demonstrate all the main signs of the chord. Power type - filtrators. Among them are the types of pelagic lifestyles, the other - bottom forms, dwell up to the ground and putting out only the front end of the body. Move through the side bends of the body.

Class Cephalochordata (Cephalochordata)

Representative of Pozhekordov is a lancing. It has an oval body, tapering to the tail. Single-layer epithelium, under the epithelium there is a thin layer of connective tissue. On the spinal side and tail there is a fin, at the end of the tail, it has the form of a lancet, the name of the animal occurs from here. On the sides of the trunk department are formed metapleral folds. Metapleral folds grow down, and then they grow together, forming a special space - an atrile cavity. It covers a sip and part of the intestines and opens outward with a special hole - atropor. The atrial cavity protects the gill gaps from the ingress of soil particles.

The skeleton is formed by chord, which stretches along the whole body. The junction tissue surrounding the chord forms the supports that support the fin and penetrate between the muscles segments (momers). As a result, partitions are formed - Miospta. Musculature transverse. Sequential contractions of momers cause side bends of the body. The chord on the front end of the body goes ahead of the nervous tube, so animals are called cereal. In the walls of the nervous tube there are photosensitive eyes. From the nervous tube, respectively, the alternation of Momers departs the dorsal and abdominal nerves. Nervous nodes are not formed. In the front of the nervous tube, neurcel expands. In this place to the nervous tube, an inflammatory body is adjacent.

By the power type, the lancer is a filter. The oral hole lies in the depths of the preliminary funnel surrounded by tentacles. Around the mouth is a sail, which is also provided with tentacles that prevent large particles into the mouth penetration. The mouth leads to a long sip, permeated with numerous gill holes. They opened in the attitudinal cavity. Local partitions are covered with fiscal epithelium, creating water current. In the walls of interjaceous partitions there are blood capillaries, gas exchange occurs in them. Breathing can also be carried out by the entire body surface.

Along the abdominal side of the pharynx passes a groove formed by cilia and mucous cells - endostil. With the help of semi-robber grooves located on the excorbable partitions, it is connected to the superior furrow. Cilia chas the mucus with pouring foods on endostil forward, according to the excorbable grooves - up and on the superior furrow - back, in the esophagus. From the intestines, at its very beginning, hesitated the blind hepatic grown. It performs a number of functions - secretory, suction and intracellular digestion. The digestive tract ends with an anal hole in front of the tailflower.

The circulatory system has a primitive structure. There is no heart. Paired venous vessels, collecting blood from the main veins, fall into venous sinus. The abdominal aorta is located under the throat and departs from the confluence of venous vessels. The abdominal aorta gives a large number of gill arteries that pass in the interjaceous partitions. They take gas exchange. Oxidized blood is collected in the spinal aorta and is distributed over all body bodies. At the lancing one circle circulation, blood colorless, gases dissolve in plasma.

The excretory system of protonphridial type is represented by numerous cells - solecitis, on the structure of the ringed worms resembling the protoferidium. Selection bodies are located on the excavatural partitions.

Undercantic separations. Gonads are at the walls of the atrial cavity, do not have ducts. Sex products go into the attitudinal cavity through the gonad wall breaks. Gamets are derived into an external environment through an atriopor. The development of the lancing proceeds with metamorphosis: there is a larva, the body of which is covered with cilia, with the help of which it moves at the initial stages of development.

Speed \u200b\u200bvertebral

The vertebral subtype (VerteBrata) is generally characterized by the following features:

1. The chord is laid in embryonic development, in adult organisms partially or completely replaced by the spine.
2. The front of the nervous tube extends to the chord ahead and differentiates in the brain consisting of brain bubbles. Bubble cavities are a continuation of the spinal channel.
3. The brain is located in the skull cavity.
4. The primary organisms on the excorbable partitions are formed by respiratory bodies - gills. In the ground vertebrates, gill cracks are found only in the early stages of embryonic development.
5. Heart occurs - a muscular organ located on the abdominal side of the body.
6. Options - kidney, which, in addition to the excretory function, perform the function of osmoregulation (maintaining the constancy of the inner environment of the body).

Class 3 Clock (Cyclostomata)

The second name of the circular chapter is frantless (Agnatha). The most primitive and the most ancient representatives of vertebrates. Known with Cambrian, the highest heyday was reached in the silver (class of global). In modern fauna, two detachments are mines and mixins. Headheads do not have paired limbs and jaws. The body is extended, there is no distinct unit on the head, torso and tail. The skin is naked, scales absent, in the skin there are many unicellular mucous glands.

On the head there is a pleasant funnel, at the bottom of which the mouth opens. Inside the funnel and at the end of the muscular language are horny teeth. On the head there is a unpaired nostril leading to an olfactory bag. Spherical gill holes are located on the sides of the head and lead in the gill bags.

Axial skeleton is formed by chord. The chord along with the nervous tube is surrounded by a connective tissue shell. The brain skull, that is, the part of the skull that protects the brain and the senses organs, is formed by a cartilage covering the brain from below and from the sides. In front of the skull adjoins the olfactory capsule, and from the sides - auditory capsules. From above, the brain is closed by a connective tissue membrane, that is, the roof of the skull is not formed yet.

The vertebrate has a visceral skull. It includes elements that are forming in the walls of the forefront of the digestive system (pharynx). From a functional point of view, this is a skeleton of gill and oral apparatuses. The discovered visceral skull is formed by cartilage supporting the mouth funnel and the language, as well as the skeleton of gill bags and the skeleton cartilage surrounding the heart.

Musculature of the body and tail is segmented - formed with clear momers, separated by miosepts.

The digestive system begins the mouth. The funds have only functions at the larch stage. In adults, it is divided into two different departments - a respiratory tube and esophagus. The stomach is undeveloped, and the esophagus immediately goes into the middle intestine. The intestine is straight, the bends do not forms. A fold is formed on the intestique tissue mucosa - a spiral valve that increases the suction surface of the intestine. Liver large. With the help of the mouth funnel, the funds are sacrificed to the body of the victim - fish and tongue do the holes in the skin of the fish. The language acting as a piston is injected into the oral cavity, from where it enters the esophagus.

Mixin has a short tentacle at the point of the oral sucker. Mixins feed on Padal. They vague into the body of dead fish, where they do move.

Gong challenges in gill slots are developing gill bags. They have an entodermal origin. In gill bags are folded with blood capillaries, in which gas exchange occurs. With breathing, water enters the gill bags through the gill holes and comes out the same way.

The heart has a two-chamber head-chain and consists of atrium and ventricle. From the sservs, venous sinus leaves, where all the venous vessels fall. Suggest arteries that carry blood to gill petals are separated from the abdominal aorta. Hanging gill artery fall into the unpaid root of aorta. Back from the root of aorta is the spinal aorta, and ahead - sleepy arteries that carry oxidized blood to the head. From the head, venous blood flows over the pair of jugular veins falling into a venous sinus. From the body, blood is collected in the rear cardinal veins. Blood from the intestines in the conduction vein, forming a gorgeous liver system. The renal system has no kidneys. In a circulation chapter one circle circulation.

Allocation bodies are represented by ribbon pair kidneys.

The brain consists of five departments: front, intermediate, medium brain, cerebellum and an oblong brain. Brain departments are located in the same plane. That is, the bends characteristic of highly organized vertebrates are not formed. Feeling authorities: organs of vision, hearing, balance, smell, touch and side line.

Separate glands do not have sex ducts. Gamets fall into the body cavity through the groovings of the gonad wall, and then through special pores on the urogenital sinus - out. Development with metamorphosis. The larva Midnog is called peckered. It dwells in fresh reservoirs, tearing into the ground. Larvae - filtrators. Development continues for several years. After metamorphosis, a young media migrates to the sea. Mixin - Development Direct. Young individuals are hatched from eggs.

Cleaning Fish Class (Chondrichthyes)

This class belongs to sharks, races and chimeras. The skeleton is completely cartilage. Scaled placoid. Five to seven pairs of gill slots. The location of steam fins is horizontal. There is no swimming bubble. The class is divided into two subclasses: plate-intensive and all-headed.

Subclass of Plate Glaba (Elasmobanchii)

Combines sharks and skates. The structure will be considered on the example of sharks. Body shape streamlined, spindle-shaped. On the sides of the head there are five pairs of gill slots. Two holes (splashes) are located behind the eyes and lead to a sip. The tail is Cloaca. The skeletal axis enters the upper, greater blade of the tail fin; This type of structure is called heterocerkal. Paired chest and abdominal fins are limbs. The males part of the abdominal fins are converted to copulation.

Numerous glands are located in the epidermis. Scaled placoid, is a plate with a direction directed back. On jaws, scales are larger and forms teeth. Outside, scales are covered with enamel. Ahead of the mouth on the head there are paired nostrils. The body is divided into two departments: torso, which starts from the last gill slit and ends with a hole of the cloaca, and the tail. Skeleton cartilage.

It consists of a spine, skull, a skeleton of pair fins and their belts and a skeleton of unpaired fins.

The spine is formed by cartilage vertebrae, inside which is very reduced chord. The upper vertebral arcs form a channel in which the spinal cord is located. The brain department of the skull consists of a brain box, Rostrum and paired capsules of the senses. In the brain box appears a cartilage roof. The visceral skeleton consists of a jaw arc, an approximate arc and gill arc. The skeleton of the belt of the front limbs is formed by a cartilage arc lying in the thickness of the musculature. The belt of the hind limbs is formed by the unpaired cartilage, located across the body in front of Cloaca. Steam limbs, chest and abdominal fins are combined to belts. Unpaired fins are represented by the dorsal, tail and anal.

On the jaws are large teeth. The mouth cavity is in a throat. The throat is performed by gill slots, the spray open in it. The esophagus is short, goes into an arcuately curved stomach. From the stomach begins the small intestine, in the front of which the gall duct is a large two-sighted liver. Pancreas lies in the mesentery of the small intestine. In the colon there is a spiral valve that increases the suction surface. The spleen is located next to the stomach.

The gill holes are excluded from each other by rigorous partitions, in the thickness of which cartilage gill arches are located. Gwee petals are sitting on the front and rear walls of the gill slots.

The heart of cartilage fish is two-chamber and consists of atrium and ventricle. In the atrium, venous sinus flows, in which venous blood is poured. From the ventricle, the arterial cone is leaving. The abdominal aorta is originated from the arterial cone. She gives five pairs of gill arterial arcs. Oxidized blood is assembled into giving gill artery, flowing into pair longitudinal vessels - the roots of the aorta, which in the merger form a spinal aorta. It passes under the spine and supplies blood internal organs. Sleepy arteries are departed to the head of the aorta roots. From the head, venous blood is assembled into paired jugular veins, and from the torso - in paired cardinal veins, which at the level of the heart merge with jugular veins, forming paired Cuvier's ducts flowing into a venous sinus. There is a gorgeous kidney system. From the intestines, the blood on the heated vein enters the liver, where the gate liver system is formed, and then the hepatic vein is poured into the venous sinus. Chickening fish have one circle circulation.

The brain consists of five departments. A large front brain goes into an intermediate brain. The middle brain forms visual shares. The cerebellum is well developed and runs back at the oblong brain. 10 pairs of cranial nerves depart from the brain.

1. The olfactory nerve - departs from the olfactory shares of the front brain.
2. Spectator nerve - departs from the bottom of the intermediate brain.
3. Overall nerve - departs from the bottom of the middle brain.
4. Blocking nerve - departs from the reckless part of the middle brain.
5. The remaining nerves depart from the oblong brain.
6. Blowing nerve.
7. Trigeminal nerve.
8. Facial nerve.
9. Auditory nerve.
10. Language nerve.
11. Nervus vagus.

In terrestrial vertebrates, in addition, the sub-surround and additional nerves occur.

Feeling organs in cartilage fish are very well developed. Large eyes have a flat cornea, a crystal ball-shaped, there is no century. Hearing organs are formed by the inner ear. The organ of the side line is a channel that occurs in the skin and communicating with the external environment with holes. The channel contains receptors that perceive water oscillations.

Allocation authorities - paired kidneys. Floor glands. The seed-winning tubules fall into the upper part of the kidneys from the tanning seeds. The seed-winning tubules are merged into the seeds, which together with ureters open in a clock on the urinary papilla.

In females, paired eggs merge, forming a common funnel, the expansion of the eggs form the shell glands, the secret of which forms the sheath of the egg. Ends the ovage "uterus". It opens with separate holes in Cloaca. Paired ovaries. Ripe eggs from the ovary overlook the body of the body and captured by the funnel of the egg. Fertilization internal, occurs in the eggs. In the uterus, eggs are developing: in the vigorous sharks to the full ripening of the embryo, and the egg-shaped eggs are distinguished from the uterus with a dense shell of the egg.

Bone Fish Class (Osteichthues)

Characterized in one way or another developed bone skeleton. A bone gill cover is formed that closes outside the gummy apparatus. Gill petals are located at the gill arcs. Most species have a swimming bubble as a spinal part of the intestines. Outdoor fertilization, development with metamorphosis.

Cleaning Ganoids (Chondrostei)

This subclass includes ancient fish, which preserved a number of primitive traits, for which they resemble cartilage fish. Representatives: sturgeon - sturgeon, Beluga, Sevrugg and others. - and weakly.

The head end ends with an elongated Rostrum, the mouth in the form of a slit is on the underside of the head. Paired fins are horizontally, the tail fins of the heterocerkal type. The body is covered with bone scales, the largest scales are called bugs.

The chord is maintained throughout life. The vertebral bodies are not formed, but there are upper and lower vertebral arcs. Bone gill lids. Like a shark, a spiral valve is in the intestines. Swimming bubble saves contact with the intestines. Heart with arterial cone. Callery is small, fertilization is outdoor. Have a commercial value.

Subclass Two-plating (Dipnoi)

Dwell in tropical, fresh, poor oxygen reservoirs. There were in Devon, the heyday was reached at the beginning of the Mesozoic. Modern representatives: Singlecomers - Neoceratodes, Dvpidosiren - Protterus, Lepidosirers.

Skeleton is basically cartilage. Chord is well developed and maintained throughout life. In the intestine there is a spiral valve. The heart has an arterial cone. Paired fins fleshy, scaled bone, tail fins Difsercal. Breath gill and pulmonary. A peculiar light serve one or two bubbles that open on the abdominal side of the esophagus. Lonanty breathing is carried out through through nostrils. The blood system acquires a peculiar structure due to pulmonary breathing. They can breathe simultaneously with gills, and light, and individually each of them. When depleting water with oxygen or during hibernation, breathing only pulmonary. Fishery does not have.

Cyclass Creeks Fish (CrossopteryGii)

A peculiar ancient fish in modern fauna are represented by one type of Latimeria (Latimeria Halumnae). Inhabit the area of \u200b\u200bComoros at a depth of 1000 meters. The flowering of the group falls on Devon and Carbon, extinct in the chalk period.

Chord is well developed, the vertebra is stuffed. Fish have degenerated light. Like two-way, the ancient cyzerings had double breathing. Paired fins in the form of fleshy blades, in which the skeleton of the fin and motor musculature is located. This is the principal difference in the structure of the limb of cyzer fish from the limbs of other fish. The body is covered with rounded thick bone scales.

Cystic and duals are likely to have a general origin. They were inhabited in fresh reservoirs with a deficit of oxygen, so they have formed double breathing. With the help of fleshy fins, cyzer fish moved along the bottom of the reservoir, as well as overwhelmed from the reservoir in the pond, which was a prerequisite for the conversion of their fleshy fins into a five-panel limb ground-type. Cystic fish gave rise to amphibians - steadacelons, first, primitive ground vertebral. Possible ancestor of amphibians are considered extinct cyzer fish - ripidism.

Ambulance Ambulance (ActinopteryGII)

The most numerous subclass of modern fish. Skeleton bone, the presence of cartilage in the skeleton is insignificant. Paired fins are vertically in relation to the body, and not horizontally, like cartilage fish. Roth is at the front end of the head. Rostrum is absent. Cloaca is not. The tail fins of homocerkal type - the blade of the fins are the same, the spine does not enter the blade. Scaled bone, in the form of thin plates, tiled down on each other.

Outcountable bony fish (Teleostei)

Fish have a streamlined body covered with bone scales. The scales are cycloid - with a smooth front edge, and Ktenoid - with a serrated front edge. It is formed scales in the skin. Outside, scales are covered with multi-layer epidermis, in which there is a large number of single-cell mucous glands. The glands are distinguished by a mucus, which reduces the friction of fish about water when driving. Scaled grows through the life of fish. On the sides of the body stretches the side line. Holes, tasking scales, lead into channels where the side line organs are located. Nervous ending perceive water fluctuations.

The spine consists of a torso and tail departments. The vertebra is bone, carry the upper and lower arcs. The upper arcs are closed and form a cerebrospinal channel in which the spinal cord lies. In the trunk department to the lower vertebral arcs, ribs are labeled. In the tail department, the lower arcs have spine processes, which makes the hemal channel. Tail veins and arteries are tested in the hemal channel.

The skull is almost entirely consisting of bone tissue and is formed by a variety of separate bones. The brain skull has a bold hole through which the connection of the spine and brain occurs. The visceral skull was formed by a series of visceral arcs: a jaw, sub-speaking and five gill. The gill apparatus cover the gill covers.

The belt of the front limbs is born to the brain skull. The skeleton of chest fins (front limbs) joins the belief of the front limbs. The belt of the hind limbs is a pair and lies in the thickness of the musculature. The skeleton of abdominal fins is born to it (rear limbs). Unpaired limbs are represented by the dorsal, tail and anal fins. Musculature, leading to the movement of the limb, is on the body body. Fish movement is provided by wave-like tail bends.

In the oral cavity of most types of fish on the bones there are conical teeth. There are no clear boundaries between the oral cavity and the throat. A throat peaned up with gill slots continues in a short esophagus that goes into the stomach. At the border of the stomach and middle intestine there are pyloric appendages that increase the intestinal surface. The middle intestine is weakly differentiated, there is no spiral valve. The front division of the small intestine is called a duodenalist. Under the stomach is a large paddle liver with a bunny bubble. The bull duct falls into the duodenum. Pancreas is formed by small slices scattered on the middle bowel. Compact spleen is under the stomach in the first bend of the intestine.

Swimming bubble is available in most bone fish. It is formed as the growing side of the esophagus. At closed fish, the bubble communication with the esophagus is lost, and in open-to-consuming - persists throughout life. The function of the swimming bubble is hydrostatic. The bubble changes the volume of gases, which leads to a change in the density of the body of the fish. In closed fish, the change in the volume of the swimming bubble occurs as a result of gas exchange in the network of capillaries that swell the bubble. At open-value fish, the volume of the bubble is changing due to its compression and expansion.

The gills serving respiratory authorities have ectodermal origin. Local partitions are absent, gill petals are sitting directly at the gill arcs. On each side of the body there are four full gills and one semi-fiber. Each gill bears two rows of gill petals. On the inside of the gill arcs are gill stamens - processes going towards the neighboring gill arc. The stamens form a commodular apparatus, which prevents the ejection of food to the outward from the pharynx through the gill cavity. In the gill petals there is an extensive network of capillaries, in which gas exchange occurs. The presence of a gill cover increases the efficiency of respiratory movements. The movements of the mouth are injected into the mouth of the mouth, and due to the work of the covers, the water is absorbed into the gill cavity and passes through the gills.

The shark uses another type of ventilation: the fish floats with an open mouth, the water is pushed through the gills. The higher the speed of movement, the more intense is gas exchange.

At fish, a two-chamber heart and one circle circulation circle. The heart consists of atrium and ventricle. From the atrium, the venous sinus is moving into which blood from the veins is going. In the heart of fish, blood is only venous. Abdominal aorta leaves the ventricle. It forms four pairs of gill arteries (by the number of gills). Oxygen-enriched blood is assembled into giving gill artery, which on the dorsal side of the body fall into the pair roots of the spinal aorta. The roots of the spinal aorta merge and form a spinal aorta, from which the vessels depart to all parts of the body. Venous blood from the tail departments reaches the tail vein. Vienna splits and enters the kidneys, forming a dotted system only in the left kidney. From the kidneys along the pair veins, blood goes forward, and from the head, also on the pair of veins - back; These veins merge, form paired ducts, flowing into a venous sinus. Blood from the intestines passes through the dialing system of the liver and on the hepatic vein falls into the venous sinus.

The brain is arranged primitive than that of cartilage fish. The front brain is small, the roof does not contain nerve cells. Medium brain and cerebellum relative to large size. The eyes are large, the cornea is flat, crystal round.

The organ of hearing consists of the inner ear (connecting labyrinth), which is concluded in the bone capsule. The capsule is filled with a liquid in which hearing pebbles are floating - otoliths. Fish are capable of publishing and perceive. Sounds are made by friction of bones among themselves, with a change in the volume of the swimming bubble.

Selication authorities: olfactory capsules lined with sensitive olfactory epithelium.

Taste organs are special taste kidneys located in the oral cavity and on the skin.

On the sides of the swimming bubble are paired sex glands. In females, the ovaries have a grainy structure, the rear departments of the ovaries perform the function of output ducts. The sexual opening opens on the urinary papilla. The seeds are long, smooth, their rear departments are converted to the removing ducts. The male sexual opening also opens on a urinary papilla.

The kidneys are long, tanning, stretch on the sides of the spine over a swimming bubble. Ureterals are departed from kidney, which merge into the unpaired canal. Some fish have a bladder, the duct of which is opened on the urinary papilla.

Icra is small, has a chatter shell. Outdoor fertilization. Development with metamorphosis. The fertilized egg is developing into a larva, which is powered by a yellow bag, the mouth does not break through the larva. As a result of metamorphosis, the larva turns into a fry - independently feeding stage of fish development. Few species of fish, such as sea bass, hermaphrodites.

The kostis fish includes the following detachments: cede-shaped, carpets, acne, pike, perch, sargana, pillable, cod, cambal and other bony fish have an important commercial value.

Supply bone ganoids (Holostei)

The flourishing of these fish accounted for the middle of the Mesozoic era. Modern fauna is represented by two types of shell pike and ameia (a flat fish) that live in fresh reservoirs.

Multid-Piece (Polyteri)

Food in fresh reservoirs of tropical Africa. The dorsal fin consists of small individual floats, hence the name.

The chordic type includes a huge number of animals, they include both primitive and very developed species, from which a person occurred.

Nervous system

Chordovy differ from other types by the presence of a central nervous system located above the chord. It was originally simple, but in the process of evolution developed to an extreme degree of complexity.

Habitat and distribution

Chordovy are divided into three subtypes, and only the vertebral managed to adapt to life both in water and on land; Shells, or urohordovye, and undecented dwell only in sea water.

general characteristics

Chordovy differ in two-way symmetry: they have a special internal organ - axial skeleton, so-called chord, or a spinal string. Chord is present in some animals in the embryo stage or larvae.

All chords have spinal chord - a solid and at the same time an elastic structure that supports their body and musculature. The rotting apparatus of chordovic is not adapted to chewing and swallowing large mining. Customized by the smallest living organisms, the chords have special organs for their capture and filtration, the main of which is a gill throat. The water drawn by mouth passes through the gill slots, and the nourishing microorganisms contained in it are delayed. Glabric throat, which also serves for breathing, undergoes indigenous changes in adult individuals.

The blood circuit consists of a pulsating organ, heart and blood vessels, which circulates blood. This structure is constantly complicated and becomes increasingly more connected with the respiratory system. With the exception of Urohordov, who are hermaphroditis, all other chord animals of divergences.

The type of chords is divided into three subtypes: urohorded, or shells, undepair and vertebral.

For Urohordov, or shells, there are many different marine animals in length from a few millimeters to 10 cm. Some are sitting, like ascidic, others are free lifestyle. Outwardly, Urohordov's body resembles a bag. Spinal chord is available only in the tail part, and in some species only in the stage of the larvae. The blood and nervous systems are reduced.

The structure of undecented has many similar features with spinal. The body compressed from the sides is covered with an epidermis. Spinal chord passes through the whole body and also has adult individuals. There are no limbs with non-examining, but there are fins, with the help of which they float, and various metallic organs along the whole body. In the front of the abdominal cavity there is a mouth without jaws, but with numerous fibers, delaying food, which is filtered from the water. A closed circulatory system consists of alone vessels: there is no cemeted heart.

Fertilization in these diverse animals occurs in water.

Vertebrates are the most highly organized representatives of the chordic type. Spinal chord is available in embryos; In adults, it replaces the axial spine, consisting of a number of cartilage or bone vertebrae. Two pairs of limbs serving for movement are departed from this solid foundation. The skin is formed by the derma and the epidermis performing the protective function.

The nervous system is a brain protected by a cranial box, a spinal cord and a peripheral nervous system. Blood, pushing the pulsating movements of the heart, circulates through the thick network of vessels, arteries and capillaries. The breathing apparatus consists of the gills in aquatic vertebrate and the lungs from the ground. A rather complex digestive system is formed in different animals by different organs.

The vertebral diverse and may be eggs (females lay eggs), egg-in-law (eggs develop in the body of the females) and niphence (the embryo is developing in the uterus, directly from it getting food).

Views

Ascidia Refers to the subtype of Urohordov. A very primitive animal of bag-shaped shape, "dressed" into a dense "dead end" - a living tissue with two holes: a rice siphon, fitted for suction of water, respiration and detention of nutrients, and a clock siphon for waste emissions.

One of the most primitive vertebrates. She has a corner-like body without jaws and limbs. The mouth is a funnel, covered by numerous indigenous teeth, which are located concentric circles, there is a language in the center of these circles. Midhoga chain, like a suction cup, attaches his mouth to his victim and sucks blood from it.

Lancelet From the subtype of undepair - a small, almost transparent marine animal, living at the bottom of the sea and representing the transitional view between invertebrate and spinal. The spinal nerve chord and tail muscles at the Lanctress look like chord and muscles of fish, but, on the other hand, he does not have any senses, nor jaws, nor skeleton.

A type	Subtype	Class	Squad	Family	Rank	View
Chordovy	urohordovye (shells)					ascidia
	umbot					lancelet
	vertebrae	headhead				lamprey
		fish
		amphibious
		presbysey
		birds
		mammals

The type of chordic combines animals, very diverse in appearance, lifestyle and habitat. Representatives of the chordovy are found in all major living environments: in water, on the surface of the sushi, in the thickness of the soil and, finally, in the air. Geographically, they are common around the globe. The total number of species of modern chords is approximately 40 thousand. The chordic type includes undecented (lancing), round-chapter (media and mixins), fish, amphibians, reptiles, birds and mammals.

Korodov, as shown by brilliant studies of A. O. Kovalevsky, also includes a peculiar group of marine, largely seating, animals - shells (appendiculory, ascidic, salmps). Some signs of similarities with chordines discovers a few marine animal groups - intestines (Enteropneusta), which sometimes also include in the type of chord.

Despite the exclusive variety of chordovy, they all have a number of common features of the structure and development. The main ones are as follows:

1. All the chords have an axial skeleton, originally arising in the form of a spinal string, or chord. The chord is an elastic inhpanese chicken, embryonic by extinguishing it from the spinal wall of the germinal intestine: chord has an entodermal origin. The subsequent fate of the chord is different. It is only for life only at the lowest chord (with the exception of Ascidia and Salp). Most of the majority of chord representatives in one way or another is reduced due to the development of the spinal column. At the highest chord, it is an embryonic organ and in adult animals in one way or another crowded with vertebrae, in connection with this, the axial skeleton from solid non-grinding is becoming segmented. The spine, as well as all other skeletal formations (except chord), has a mesodermal origin and is formed from a connecting woven case surrounding chord and nervous tube.

2. Above the axial skeleton is the central nervous system of the chord, represented by the hollow tube. The cavity of the nervous tube is called neurcel. The tubular structure of the central nervous system is characteristic practically for all chord. The exception is only adult shells. Almost all of the chordanese front department of the nervous tube grows and forms a brain. The inner cavity is preserved in this case in the form of ventricles of the brain. Embryo nervous tube develops from the dorsal part of the ectodermal incarnation.

3. The front (pharyngeal) department of the digestive tube is communicated with the outer medium with two rows of holes that called visceral slots. The lower forms on their walls are gowns. The gill cracks are allowed only in lower water chords. In the rest, they appear only as embryonic formations operating at some development stages or not functioning at all.

Along with the three main features of the chords, the following characteristic features of their organization should be mentioned, which, however, except the chords and representatives of some other groups. Chordish, as well as

The type of chord is about 50 thousand species. Habitat: ground-air, water, soil. Lifestyle - free-lived. Chord animals are very diverse, but have a number of common features of the structure.

1. Three-layerness - The body develops from three germinal leaflets: Etoderma, Mesoderm, Entoderma.
2. Vertiality - Roth is formed at the end of the body opposite to the blastopore tab.
3. Bilateral symmetry.
4. Secondary body cavity.
5. Metamerism (Parity, Repeatability) many organs.
6. Body cover Presented with leather consisting of epidermis and dermis, and its derivatives: scales, glands, horny shields, feathers, hair.
7. Chordovy have internal skeleton. In the simplest case, it is represented chordoy. The chord has a kind of elastic rod and is located along the body. It is formed from the Entoderma. In undecented chord, it remains throughout the life, and the vertebrates exists only in the embryonic period and is subsequently replaced by a cartilage or bone spine.
8. central nervous system Located on the dorsal side of the body over the chord. It has a view of a tube with a narrow canal (cavity) inside - neuroception. The vertebrates from the front unit of the nervous tube formed a brain, and from the rest of the spinal cord.
9. Circulatory system closed. The heart (or vessel, replacing it) is located on the abdominal side of the body under the digestive tube. The heart can be 2-, 3- or 4-chamber.
10. Digestive tube Located under the chord. Its front (pharyngeal) department is communicated with the external environment by two rows of gill slots.
11. Respiratory system Lowd in the form gill slotsthat permeate the wall of the front digestive tube - pharynx. Water forms on their basis develop gills. In the ground forms, gill slots are available in the embryos, during embryogenesis they will overgrow, and adults develop lungs. Lights develop from the rear of the throat.
12. Allocation authorities: Nephond or kidney, which can be torso (in lower vertebrates) or pelvic (at the highest vertebrates).
13. Most chordan separations. The reproduction of sex. Development direct or with metamorphosis.

Systematics. The type of chords is divided into three subtypes: shells (larvoy-chorded), undecented (croof), vertebrates (skull). W. heavymen The chord is only in larvae (class of ascadium). W. undecented (braid) There are chord, but there is no separate head and skull (class of lancing). W. vertebrates (skull) There is a spine with vertebrae, skull, head and spinal cord, heart. The vertebral subtype divide the classes: cartilage fish, bone fish, amphibious (amphibians), reptiles (reptiles), birds, mammals.

Lankers class

Water habitat: shallow water temperate and warm seas.
Structure. The body is 4-8 cm long, elongated, compressed from the sides and pointed at both ends. Along the back stretches dorsal (skin fold) that goes into tail fin., similar to a surgical tool lancet. Body sides are paired metapleral folds - Analogs of paired extremities of higher chords.
Body cover. The body is covered with smooth skinconsisting of single-layer epidermis and jellious dermis. Body covers are transparent because they do not contain pigment cells. Skin derivatives - single-cell glands, isolated mucus.

Skeleton presented chordoy. It is a dense elastic rod consisting of special cells closely adjacent to each other. The chord of the lancing stations remains throughout and is not differentiated to the departments.
Muscular system Formed by muscles in the form of two longitudinal tapes located on the sides of the chord mainly on the dorsal side of the body. Ribbons are separated by partitions into separate parts. Such muscles allow you to make monotonous, primitive movements - bending and blending the body.
Digestive system Little is different and consists of a mouth of a pole, surrounded by 10-20 pairs, a supreet, pharynx and intestines ending with anal hole. The wall of the pharynx is permeated gill sluts (100-150 pairs) leading to near-gill cavity. Together with the current of the water created by the tentacles, unicellular plants and animals, small crustaceans, which settle at its bottom in a special deepening come into the throat. Water through the gill cracks goes into the community cavity and then through her hole ( atriopor) To the external environment. Food enters the intestines and digested, unbelievable residues are output through the anus outward. Method of nutrition - passive, water filtration. The intestine of the lancing has a blind growing, performing the function of the liver.
Respiratory system. Breathing occurs simultaneously with meals. Gill slots are located on the sides of the pharynx. They are divided narrow inter-chamber partitionswhich pass blood vessels. Gas exchange occurs in the vessels of interjaceous partitions.
Circulatory system Closed, with one circle circulation. There is no heart, its function performs pulsating abdominal AortaLocated under the throat. From the abdominal aorta depart glabric arterieswho carry venous blood to the respiratory authorities. In the vessels of interjaceous partitions, blood is saturated with oxygen and enters spinal aortaAnd then to all organs and tissues, where it becomes venous. Further by four cardinal Vienam (two front and two rear) venous blood is going to the abdominal aorta. Blood is colorless.
Selective system. Observation bodies - nephond, like rilly worms. They are metairly located on the sides of the pharynx. One end of jade opens as a whole, the other - in the accommodation cavity.
Nervous system Presented nervous tubelocated over the chord. It consists of nervous cells, has the same structure throughout, cavity ( neurcel) and expansion in the forefront (olfactory fossa). From the nervous tube, peripheral nerves are departed. There is no brain.
Sense organs. Vision organs - hesse eyes. These are pigment cells located along the entire length of the nervous tube and perceive light irritation. Touch bodies - tactile cells in the skin. The sense of smell is obony Yamek.. This expansion in the front of the nervous tube perceives chemicals.
Reproduction and development. Lankers separatogs. Policy dimorphism is not expressed. The reproduction of sex. Sex glands have the type of paired rounded protrusion (25 pairs) on the body surface, in the incoming cavity. They do not have their own ducts. In the ripening of genital cells, the walls of the gland is breaking down and with a current of the water of the sperm and eggs enters the environment. Fertilization occurs in water. A larva is developing from the fertilized egg that actively floats, it feeds and gradually turns into an adult individual. The type of development is indirect.

Fish

About 25 thousand species are known. Habitat - water. Fish are ancient primary vertebrates. All features of the structure and functions of organs, ecology and behavior of fish are related to life in water. Unlike undepair, they lead an active lifestyle. Move as a result of bending body, tail and fins.
Systematics. Fish belongs to the superclass of the ministeur. It includes a class of cartilage fish (sharks and skates) and class of bone fish (cystic, two-plating, bulk and bony).
Structure. For most fish, a spindle-shaped, streamlined body shape is characterized. Body length from 1 cm to 20 m or more, body weight from 1.5 g to 14 tons.
Body departments: Head, torso, tail, fins. Frames of fish are divided into pairs ( breast and abdominal) and unpaired ( tail (two-haired), anal, dorsal (one, two or more)). Anal and dorsal fins provide body stability when driving forward and when turning. The tail participates in the move forward. Pairies provide body turns, stop, save equilibrium; Breasts, moreover, serve steering depths.
Body cover represented skinconsisting of multilayer epidermis and dermis. Derivatives: bone or placoid scales and single-celled mucous glands in the epidermis. The mucus reduces the friction of water. Schee It may be bone (in bone fish) and placoidal (in cartilage fish). Bone scheat It has the appearance of thin, plaques, laminated on each other, flakes are tiled. Placoidal Scales have a teeth. All types of scales and vertebrate teeth are placoid scales derivatives.
Skeleton Fish cartilage, bone-cartilage or bone, consists of three departments: the skeleton of the head, the skeleton of the body and the skeleton of the limbs. The skeleton of the head (skull) includes facial and brain departments. The brain department protects the brain, facial - contains moving jaws with teeth, gill arcs and gill lids. Skeleton - spine, consists of two departments: torso and tail. Vertebra Consists of body and processes. The appearance of the vertebrae was a large aromorphosis. They attach strength and flexibility of the skeleton, are protection for the spinal cord. With the torso vertebrae, Röbra is articulated. The skeleton of the limbs is represented by bone or cartilage rays of fins.
Muscular system Mainly represented by muscle ribbons on the sides of the body separated by segments, and individual muscles of the jaws and gill covers. The muscles of the jaws, gill arcs, back, the tail of the fins are well developed.
Digestive system It consists of a mouth, pharynx, esophagus, stomach, small intestine, colon, ends with anal hole. There are liver, gallbladder, pancreas. Many fish have teeth. Fish's teeth have the same structure and are replaced throughout life.
Respiratory system Presented goryrami.consisting of gwee Doug., each of which are on the one hand label petalspenetrated by capillaries and on the other - gill stamens (CEDNELOUSED). At bone fish outside the gills covered gill lids. In the gill petals there is a large number of capillaries, which is necessary for gas exchange. Some fish additionally breathe skin, some capture atmospheric oxygen in the mouth, two-ways have the addition organs of breathing - the so-called lungs. Also, the respiratory function can be swaming bubble.
Hydrostatic apparatus. Swimming bubble - Missing intestinal growth, gas filled with gas. Some have no. The swimming bubble performs a hydrostatic function: adjusting the content in it of gases, the fish can change the body density and thereby affect its buoyancy. The expansion of the swimming bubble makes it easier to rise, the compression is increasing down. In addition, it is a resonator (amplifier) \u200b\u200bof sounds. In bubble bubble and cycular fish, the swimming bubble has a cellular structure and, essentially, functions as light.
Circulatory system closed. Unlike undeperitive, the heart appears. It is two-chamber, consists of atrium and ventricle. Most fish have one circle circulation circle. The heart contains venous blood. From the ventricle, blood gets in arterial cone.further in its continuation - abdominal aorta, and from her to the gills. Gybel capillaries take gas exchange. Arterial blood enters spinal aorta, then to organs and tissues. The venous blood in four fundamental veins is collected in the venous sinus, which flows into the atrium, and it enters the ventricle. However, in two-way and cyzer fish, due to the advent of light, the second circle circulation is formed. In the atriums of the two-plating fish there is a small partition that divides it on the right and left half. Fishs do not have a constant body temperature (pallotermic animals).
Selective system Includes kidneys, ureters, bladder, output duct. At fish primary (trunk) kidneys. They have the form of long tapes located along the body. The main exchange product - ammonia. Watering from the kidneys along the ureters enters the bladder, and then dismissed through an independent hole.
Nervous system consists of central and peripheral. The central nervous system includes a head and spinal cord. The brain has 5 departments: front, intermediate, medium, rear (cerebellum) and oblong. The most developed medium brain containing the centers of view, and the cerebellum, coordinating the complex movements of fish. The peripheral nervous system includes 10 pairs of brain nerves and spinal brain nerves. In the behavior of fish, unconditional (congenital) and conditional (purchased) reflexes are manifested.
Feeling authorities: Side, sense of smell, vision, hearing, equilibrium and taste. Selication organs - paired olfactory bags communicating with the external environment through nostrils. Sneakers of fish can capture at a very long distance (up to 500 m or more). Side Line - Special fish organ, perceiving water pressure. This is a channel in the thickness of the skin on the sides of the body, communicating with the outer medium near the holes and containing sensitive cells, perceive the direction and strength of water current, as well as very thin sound oscillations. Vision organs - eyes having a ball crystal and a flat cornea. They are adapted for vision at close range. The organ of hearing and equilibrium consists of the inner ear, which is reputed labyrinth. Fish can not only catch the sounds, but also to make them. Touch bodies are sensitive cells located in the skin throughout the body, especially on fins and lips. Taste organs - taste cells in the oral cavity.
Reproduction and development. Pisces mostly separately. Samka one or two ovarian Granular structure in which Ikrinki develops, the male has two semennik Leng-shaped form, in which milk with spermatozoa are formed. The reproduction of sex. Insemination in most views are outdoor. There are vivory. In cartilage fish, development is direct, in bone development with metamorphosis, larva - Malek. Reproduction ( spawning) It occurs in the places most favorable for the development of embryos inside the eggs, the development of fry. Some species of fish are distinguished by large fertility, others - highly developed concern about the offspring (barley). Some types of fish ( busy) They live in the seas, and Ikra droop into rivers (for example, salmon) or vice versa (for example, European eel lives in the rivers of Europe, and multiplies off the coast of America in Sargasso Sea).
Origin and aromorphosis. The following aromorphoses led to the occurrence of fish: the occurrence of the spine and the skull, the jaws equipped with teeth, the paired limbs - fins, the inner ear, primary (torso) kidneys, a two-chamber heart on the abdominal side of the body.
Value. Fish used by man in food (meat, caviar, liver), are a source of raw materials for industry.

Classic fishing classes

Currently, cartilage fish has about 730 species. Representatives of cartilage fish - sharks, skates, chimeras.
The shape of the body is belonging or flattened in the spinal abdominal direction. Skeleton cartilage throughout life. For fish of this class, the absence of bone tissue is characteristic. Some have a placoidal (deactive) scales. There are 5-7 par gill slotsopening out. There is no swimming bubble. Anal and urinary openings are located at the base of abdominal fins. Fertilization outdoor or internal. The focusing organs in males develop from abdominal fins. The reproduction occurs in the way shipping eggshaving a leathery shell by way eggswhen the egg remains in the ovage up to the birth of the fry, or by alignment, in which the embryo is developing in the ovage, feeding due to the substances of maternal blood, and comes out completely ready for independent life.
Sharks. About 250 species are known. Sharks predominantly sea animals, live in the thickness of water or around the bottom, at a depth of up to 3 thousand meters. Mostly inhabitants of the tropics. Most predators. Plankotofagi (whale and giant shark) are found. The body of the shark elongated, torpedo-shaped, from 20 cm and up to 20 m long. Usually 5 pairs of gill slots on the sides of the head. Powerful tail fin, heterocerical (non-equal). Teeth are sharp and powerful.
Skats. It is known about 350 species. They live in the seas and oceans, mainly at the bottom, only a few live in the thickness of the water (manta, tapes). Skates - benstofagi - Feed by benthos (inhabitants of the surface of the bottom and soil). The body of the skates is flattened, wide. The skin is naked or covered with spikes. Five pairs of gill slots are located on the abdominal side. The edges of the chest fins are fascinated with the sides of the head and body, the dorsal fins are located on the tail or there are no them; Breast fins are greatly enlarged.

Class bone fish

Bone fish - This is a numerous class, including as ancient species of fish - cysthematics (coelacanth), dipnoi (Rogozub), bone-cartilage, or sturgeon (Sevryuga, Osperature, Beluga, Sterlet), and a huge group currently flourishing - kostysy fish. Kostyish fish Make up more than 90% of all types of fish. These include cele-shaped (trout, pink salmon, keta), carpets (bream, lin, sazan, roach, crucian), salmon, gracious, quantities, sophisticated, etc.

Amphibian class (amphibians)

About 4 thousand species are known. Representatives: Frogs, Toads, Gerlyanka, Tritons, Salamandra, etc. Most amphibians live in warm wet countries. They have features of both aquatic and ground-air habitat: breathe air oxygen with light and oxygen contained in water, through the skin; easily move on land and in water; For reproduction, water is necessary; eggs do not have protective shells; Development occurs in water, adult forms live near the reservoirs, in a humid environment.
Structure. Body departments: Head, torso, tail, front and rear five-plated limbs. The tail is available at tailed amphibians. The hind limbs have swimming membranes, against the rigorous limbs are reduced.
Body cover Posted by leather consisting of multilayer epithelium and dermis. The skin is thin, soft, naked, abundantly moisturized by the secrets of numerous mucous glazes. The secreted mucus makes the skin constantly wet, which protects it from drying, has a bactericidal action, contributes to gas exchange. Leather permeable for gases and water. Most oxygen (up to 65%) penetrates through the skin. Many in the skin have glands whose secret is toxic.

Skeleton Consists of three departments: the skeleton of the head, the skeleton of the body, the skeleton of the limbs and their belts. In the skeleton a lot of cartilage. Skeleton head (skull) It has two departments: brain and facial. The mobility of the head relative to the body is small. Skeleton torso It is represented by the spine, which consists of four departments: cervical (1 vertebral), torso (7), sacral (1), tail. The cervical and sacral departments for the first time appear in amphibians and have only one vertebra. The abrupt 12 tail vertebrae will be afraid into a single bone - warrow. There is no chest and roother. Skeleton of the belt of the front limbs Forming pair blades, clavicle, rope bones, connected to the sternum. Skeleton of a free forefinder It consists of a shoulder bone, two bones of the forearm (elbow and radius) and brush bones, including wrist, stain and phalange of the fingers. Skeleton belt rear limbs Presents a pelvis, which consists of consistent pair of iliac, seeded and pubic bones. Skeleton of free rear limb It consists of femoral bones, legs (large and small berthovy bones) and feet bones, including prelice, plus and phalange of the fingers.
Muscular system Differentiated to a greater extent than fish, is represented by a variety of individual muscles, largely loses its segmentation characteristic of the muscles. The most developed muscles of the hind limbs.
Digestive systemit consists of a rotoglota cavity, esophagus, stomach, small intestine, colon, ends with a closer. There are liver, gallbladder, pancreas. Salmon glands appear, but their secret does not contain enzymes. The frog has a long, sticky tongue attached by the forefront to the lower jaw, which allows you to throw it away far away when catching extraction. Most species on jaws have small homogeneous conical teeth, contributing to capture and retention. Adults are powered by various invertebrates, predominantly insects, larvae (tadpoles) are also plants.
Respiratory system. In adult animals - thin-walled largest lungsnot having partitions, larvae - Zhabra. The respiratory surface of the lungs is small, therefore, the skin plays a large role in the gas exchange of amphibians: 65% of gas exchange is operating, 35% - lungs. The respiratory tract is not differentiated and presented. gunted trachene chambercontaining voice apparatus. Air injection into the lungs occurs due to the reduction in the muscles of the bottom of the rotoglotor. Some species are missing (raceless salamanders).
Circulatory system Closed, two circles circulation. Heart Three-kamer: Two atrium and one ventricle (at the light-free forms of two-chamber). Inside the ventricle there is a partial mixing of arterial and venous blood. From the right side of the ventricle leaves arterial cone.distributing blood in three vascular pairs. When reducing the ventricle, the least oxidized (venous) blood is pushed out, then mixed and then the most saturated with oxygen (arterial) blood. Venous blood in skin-lung The arteries flow to the respiratory authorities - light and skin (small circle), mixed blood on the right and left arcs of the aorta enters all organs and tissues (large circle), arterial blood - sleepy Arteries to the brain (big circle). Arterial blood from the respiratory organs flows to the left atrium on the lightweight veins. Venous blood from organs and tissues is collected in the right atrium on the front and rear hollow veins. Body temperature is non-permanent (pallotermic animals).
Nervous systemconsists of central and peripheral. The central nervous system includes a head and spinal cord. The brain has 5 departments: front, intermediate, medium, rear (cerebellum) and oblong. The front brain is better developed than in fish, it has a large size and divided into 2 hemispheres. The cerebellum is designed worse than fish, which is due to more primitive movements of amphibians. The peripheral nervous system includes 10 pairs of brain nerves and spinal brain nerves forming the plexus.
Sense organs. Vision organs - eyes having mobile century, convex cornea and two crystals. The hearing body is an internal and secondary ear with an Eustachius pipe (it allows you to balance the air pressure in it with the pressure of the external environment), drumpowder and one hearing bone (column). The sense of smell is nostrils, taste - language, touch - leather. The larvae and adult animals that are constantly living in the water, the side line is expressed.
Selective system. Primary (trunk) kidneyslocated in the body on the sides of the spine, ureters and bladder. From the kidneys along the ureters urine enters the clock, then in the bladder, which is periodically emptied. Product exchange - urea.
Reproduction and development. All amphibian separations are expressed by sexual dimorphism. Sex glands (ovaries and seeds) pair. The seeding channels are opened in ureters, eggs - in Cloaca. Reproduction only sex. Outdoor seeding (paneous) or external internal (tailed). Eggs (caviar) are laying off into water or water plants. Development S. metamorphosis. The larva (taddastic) on the structure is significantly different from adult forms and resembles Fish Fish. The headastr has a gills, a side line, a two-chamber heart, one circle circulation. Some tailed (ambistum) is peculiar necknowledge - reproduction at the larval stages of development. Ambistray larva has branchy gills and called axolotl.
Origin and aromorphosis. First amphibians ( steodamefala) It happened from cisterers. The adaptation to life on land was accompanied by large aromorphosis: the transformation of pair fins in the limb of ground-type, differentiation of muscles, the development of the lungs, a three-chamber heart, a light circle of blood circulation, the appearance of cervical and sacral spinal sections and moving skull-hazing, the improvement of the senses.
Value. Amphibians regulate the number of many invertebrates. In a number of countries, some amphibians are used in food by man. Separate species are classic objects for laboratory research.
Systematics. The amphibian class is divided into detachments: legal, tailed and eager.
A squad of a naked. Representatives: worms, fish meters, etc. Characterized with a worm-shaped body shape. Limbs and tail are missing. Lead an underground lifestyle, larvae develop in reservoirs.
Detachment tailed. Representatives: Tritons (ordinary, comb, needle), salamandra, ambistraims, etc. in appearance resemble lizards, but their skin has no scales. The body is elongated, the tail is long, the front and rear limbs of almost the same length (the rear pair can be reduced), eyes of a unkill. Dwell in small standing reservoirs. They float with the help of the tail, and the legs pressed to the body. Winter on land in soil shelters, in a heaps of leaves, under stumps.
The detachment is taped. Representatives: Frogs (herbal, butterordy, pond, lake), toads (gray or ordinary, green, reed), Kwakshi, Gerlyanka, etc. are the most highly organized group of amphibians. Dwell near reservoirs. The flat head goes into a wide torso, the tail is missing. Tops are longer and stronger than the front. Rear legs are used to repulsion, front legs - to mitigate landing. The hind limbs have 5 fingers, between which the swimming meters are stretched. In the reservoir, packed float, on land moving short jumps. The toad the skin is rough, covered with warts (tuberculous), under them are glands that allocate a poisonous secret to protecting from enemies. Toads are more slow in movements and lead a nightlife. Quakes live on trees. Down is descended only in the spring for fun and autumn to winter.

Class of reptiles (reptiles)

More than 8 thousand species of reptiles are known. Habitat - ground-air or water. Reptiles can live, multiply and develop away from water bodies. Crocodiles, sea turtles and sea snakes again moved to life in water. Most species live in latitudes with a tropical climate.
Representatives: Lizards (hip, vivoriable), Varan Gray, Yolkopusik, Ordinary, Crocodile Nilsk, Turtle Central Asian, etc.
Structure. Body departments: Head, neck, torso, tail, front and rear five-plated limbs. The shoulder and femoral bones are located parallel to the surface of the Earth, so the body of reptiles saves between the limbs.
Body cover. The skin consists of multilayer epidermis and dermis. In contrast to amphibians in reptiles, the skin is dry, almost devoid of glands, most covered with horny scales or shields. Horn scales and shields - epidermis derivatives. They protect the body from water losses, mechanical and other influences. Some species under the horn scales are bone plates forming the shell (turtles). Scales are constrained, so for reptiles is characterized by molting.
Skeleton Consists of three departments: the skeleton of the head, the skeleton of the body, the skeleton of the limbs and their belts. The skeleton is almost completely infinite. Skeleton head (Skull) includes two departments: brain and facial. The skull has an elongated form at the expense of bones. Increases the volume of the brain department. There is a solid palate separating the nasal cavity from the mouth. Spine It consists of five departments: cervical (8-10 vertebrae), chest (5), lumbar (17), sacrilate (2), tail (several tens of vertebrae). The first two vertebra - atlant. and epostroinet. The first is connected to the skull and has a hole, the second has a dental extension, which is included in this hole. Such a connection ensures the mobility of the head. There are ribs. Front ends Rybers of the thoracic spine are connected to the sternum, forming chest. The skeleton of the belts of the limbs and the skeleton of free extremities Similar in the structure with those of amphibians. On the fingers of the limbs there are claws. The snakes the spine is formed only by the torso and tail departments, the skeleton, the skeleton of the limbs and their belts are reduced. Lizards, tail verteons can be broken in the middle, where there are thin cartilage interlayers that divide the body of the vertebral into two parts.
Muscular system More differentiated than amphibians: Neck muscles appear, interrochematic, subcutaneous, flexors and finger extensors.
Digestive system It consists of mouth, pharynx, esophagus, stomach, small intestine, colon, fitting of a blind intestine, ends with a closer. The digestive tract has a big length and more differentiated to the departments than that of amphibians. The mouth cavity is separated from the pharynx. It contains homogeneous conical teeth and language. The turtles have no teeth, the edges of the jaws are covered with a horny case. Snakes and lizards language at the end of a split. On the border of the thin and colon is the embossed slicer. There are liver, gallbladder, pancreas, salivary glands. The secret of salivary glands contains enzymes. Some snakes and lizards, this secret is poisonous. Most reptiles feed animal food.
Respiratory system Consists of respiratory tract and lungs. The airways include the nasal cavity, larynx, trachea and bronchi. The nasal cavity has an outer breathing holes (nostrils) and internal breathing holes ( hoans) opening up in the oral cavity. Next follow larynx and trachea, the rear end of which branches off 2 bronchi.incoming B. lungs. Lights have a fine-stricter structure and inner partitions that increase the area of \u200b\u200bgas exchange. The presence of a chest provides a refine type of breathing, which first appears in reptiles. The respiratory movements are provided by the reduction of interrochemical muscles changing the amount of the chest.
Circulatory system Closed, two circles of blood circulation, a three-dimensional heart, consisting of two atrial and one ventricle having an incomplete partition. (Crocodiles have a four-dimensional heart.) Arterial cone is reduced. From different parts of the ventricle, 3 vessels are departed independently of each other. From the right side of the ventricle leaves easy arterycarrying venous blood to the respiratory organs (a small circle of blood circulation). Oxidized blood on the lightweight veins returns to the left atrium. From the left side of the ventricle leaves the right arc of aortawhich carries arterial blood to the head (big circle), from the middle of the ventricle - left arc aortaIt comes into it mixed blood to all organs and tissues (big circle). According to the system of hollow veins from all organs and tissues, venous blood is collected in the right atrium. Body temperature is non-permanent (pallotermic animals).
Nervous system consists of central and peripheral. The central nervous system includes a head and spinal cord. The brain has 5 departments: front, intermediate, medium, rear (cerebellum) and oblong. The brain and cerebellum are well developed in the brain. The volume of the front brain is greater than that of amphibians, on its surface appears bark in the form of three islands. References are more easily developed, their reflex activity is more complicated. Reptile cerebellum is better developed, it coordinates their more complex movements. The peripheral nervous system includes 12 pairs of cranial nerves and more developed than amphibians, nervous plexus, innervating limbs.
Sense organs. The organs of view - the eyes, well developed, the lens can change the curvature, appears third eyelid - Mugative membrane. Some reptiles have dark eyeIt is located on the temperature, associated with the intermediate brain, perceives infrared radiation. Hearing organ - internal and secondary ear with one hearing bone and eardrum. The sense of smell is the receptors of the nasal cavity, touch and taste - a split language.
Selective system Presented secondary (pelvic) kidneys, ureters and bladder. Secondary kidneys provide active reverse absorption of water from primary urine and produce concentrated urine. Watering from the kidneys along the ureters enters the clock, then in the bladder, which is periodically emptied. The main product of the metabolism is urinary acid.
Reproduction and development. Reptiles separately. Sex glands (ovaries and seeds) pair. The seeds and eggs are opened in Cloaca. Seamation internal. The females of most reptiles are laying large eggs rich in the yolk and coated with a solid leather shell (at lizards, snakes) or limestone (in crocodiles and turtles). Some reptiles are infectious about eggmifting and legability (a lizard whip, Vijuki ordinary). Development direct. The embryo is developing inside the egg in the aquatic environment.
Value. Regulate the number of miserable rodents, mollusks, insects. Eggs and meat of a row of reptiles are used in food by man. The skin of crocodiles, large lizards and snakes serves as raw materials for leather production. From the turtle shell make rims for glasses, ridges, etc. Poison serpent is used in medicine (poison cobra, viper, sandy ephon).
Security. Rare Reptiles (Gray Varan, Central Asian Cobra, Far Eastern Turtle) and some other reptiles need protection.
Origin and aromorphosis. Reptiles originated from the first amphibians ( steodamephalov) In the coal period of the Paleozoic era. The appearance of the reptiles contributed to the fractures of the front brain cortex, secondary (pelvic) kidneys, the differentiation of the respiratory tract, cellular light, rolling articulation of the skull and spine, the formation of the chest, an incomplete partition in the ventricle of the heart, the shell shells of the eggs and a germ shell - amnion.
Systematics. Class Presbysey divide on squads: beakhead, scaly, turtles and crocodiles.
Detachment of beakheads. Very ancient group, the modern representative of which is the only appearance gatteria. It has a primitive structure, externally resembles a lizard. It dwells on the islands of New Zealand.
Detachment scaly. Includes lizard suburbs, snakes, chameleons. Characteristic sign - availability horny scales and shield.
The cross lizard (Gecko, Agama, Varana, Spine, Jumping Lizard). It is inhabited in the steppes, deserts, forests, mountains, etc. For lizards, an elongated body with a long movable tail is characterized, a well-pronounced neck, moving eyelids. Feed insects, live in nonorah under the stones or roots of trees. Have minor sizes. Horny cover changes over the summer 4-5 times. Seamation internal. Eggs are covered with a dense protective sheath. The female bursts them into the hole. Characteristic regeneration.
Snake cross (Fleavings, deck, aspids, viper, shielding). Adapted to crawling on the ground, shrubs, trees. The body is long, cylindrical. Greet, limbs and their belts, bladder, as well as the right light reduced. The neck is not expressed, crawling on a belly. The skin is periodically reset when molted. In the spine from 140 to 435 vertebrae. Eyelids fraught, transparent (non-moving look). The eardrum is absent. Some snakes find prey with the help of a thermal sprocket that reacts to the thermal radiation of animals. Prey swallowed entirely (jaws have tensile ligaments). The throat, the esophagus and the stomach are also able to stretch. They exterminate rodents. Most egg-owned, but there are eggshawn. Most snakes Neyovitis (custody, poloz, beats, etc.). Poisonous snakes have poisonous teeth and glands. The two front teeth of the upper jaw are larger, have grooves or channels for which the poison flows at the bite. This is the secret of poisonous (modified salivary) glands. The poison of some snakes (Gurza, Gadyuk, ephon, a shielding) acts on the blood and blood circuit, others (cobra) - on the nervous system. When the snake bite, it is necessary to immediately introduce the victim of the antidoteral serum, after setting the appearance of the bite snake. A large amount of serpentine poison poisons the human body, small doses are used in therapeutic preparations.
Chameleon sub surveys . Adapted to the woody lifestyle: the body is compressed from the sides, the legs are long with fingers similar to claws, for girth of the branches of trees at climbing. When catching insects can throw out a long tongue. Create painting in order to mask.
Detachment Turtle (Swamp, Caucasian, Central Asian, Caspian). Have bone shell (The upper part of it grows with the ribs and the spine, the bottom - with the sternum and the clavicle). The shell is free only head, neck, tail and limbs. With the danger of the turtle removes them under the shell. The armor is covered with horny shields. There is no teeth, their function performs horny beak. The brain is poorly developed, but the spinal cord is massive. Lead ground or water lifestyle. Ground forms feed on plant food, water - predators. Light spongy structure. In respiration, shoulder and pelvic muscles take part, since the chest is fixed. The marine turtles of the limbs are converted into flippers. Flip in summer or winter hibernation. Egglades.
Squad crocodiles (Swamp, Nile, stupid). Dwell in tropical latitudes. The length of the body reaches 2-7 m. Lead a semi-water lifestyle. Rear legs have swimming membranes. Most of the days are carried out in water, for breeding and relaxing come to the land. Hunt usually at night. Predators, feed on large invertebrates and fish. The body, tail and limbs crocodiles are covered horny shieldsunder which are located bone plates. Crocodiles are the most highly organized representatives of the commercial class. They have a four-dimensional heart (but the blood is partially mixed), well-developed solid panel; Teeth are in the cells of the jaws; in lungs a lot of internal partitions; A more perfect nervous system, complex behavior.

Bird class

Includes about 9 thousand species. This is the most numerous class in the number of species among other classes of terrestrial vertebrates. Birds are highly organized warm-blooded vertebrates that adopted to the flight. Dwell everywhere from the Arctic to Antarctica; Most dwell in the tropics (about 80%). Habitat: ground-air, water. Flying (eagle), floating (penguins) and running (ostrises) species are found.
Structure. Body departments: The body is divided into head, neck, torso, wings (front limbs), legs (rear limbs) and tail. It has a streamlined form.
Body cover. The skin is thin, dry, is deprived of glasses. Only over the tail in most birds there is a cleaner iron. Its secret serves to lubricate feathers and protects them from water. Skin derivatives: claws on the fingers of the legs, horny shields on the legs, cornese covers of beak, feathers. Feather cover promotes thermal insulation, body streamlings, skin protection from mechanical effects. Feathers There are contour and dying. Contour feathers Consist of hollow rodto which attached fan. The foam consists of numerous long-order long-order beards, on which there are second-order beards, equipped with small hooks. The latter connect these beards among themselves. The bottom of the rod submersed in the skin is called whane. Down feathers Formed by a thin rod and beards of only first order. The contour feathers are located on the tail (steering), on the wings (fly), on the body (crumbling). Flying feathers, forming a wing, maintain a bird in flight, steering - control the flight and brake when landing. Worn feathers are replaced by new in seasonal lines. Skeleton The birds are lightweight (since the cavities of tubular bones are filled with air) and durable (at the expense of the fire of bones). It consists of three departments: the skeleton of the head, the skeleton of the body and the skeleton of the limbs and their belts. Skull It does not have seams, his bones firmly grow together. There is beak. Spine It consists of five departments: cervical (up to 25 vertebrae), chest, lumbar, sacral and smoking. The cervical spine has a significant length and very large mobility. The rest of the departments can fire. A breastfish is developed, the chest has increased - keel - To attach the chest muscles. The last tail vertebrae is growl into the cockerels ( pigtyl), serving support for steering feathers. The belt of the front limbs consists of three paired bones: rose, blades, clavicle. The clavicle is growing, forming fork. The skeleton of the wing consists of a large shoulder bone, two bones of the forearm (elbow and radius), controversial of the wrist bones, the peel and the preceded phalanx of the three fingers. The belt of the hind limbs consists of three pairs of bones: iliac, sedanized and pubic, struggling with each other. The lower ends of the pubic and sedan bones are not connected, the pelvic belt below remains open, so birds can carry large eggs. The skeleton of the hind limb consists of femur, two inacted large and small berth bones and feet. The skeleton of the feet includes a set (threw bones of plus and repulse) and phalanges of 4 fingers, 3 of which are directed forward, 1 - back.
Muscular system. The muscles of the neck, chest (flying) and legs are well developed. Muscle mass is up to 25% body weight.
Digestive system It consists of a mouth, pharynx, esophagus, two-chamber stomach, small intestine, colon, ends with a clock. There are liver, pancreas. Slying glands are missing or developed weakly. Short language. In the birds there are no teeth, their functions (capture and retention) are performed by the corporate edges of the jaws (horny covers) forming beak. Verify the top (cluster) and lower (connected) jaws. In some birds (predators, chicken, pigeons) a long esophagus form an extension ( goiter) - Place of storage and softening of food. In the pigeons of the wall of the goiter during the feeding period of chicks, a curly substance is distinguished - "Milk", which birds feed chicks. The lack of teeth and the need for intensive mechanical and chemical impact on food led to the formation of a two-chamber stomach. IN irony Department The stomach of food is subjected to enzymatic effects of gastric juice, in muscular - mechanical grinding with a reduction in thick muscle walls and pebbles, swallowed by birds. The fat intestine is short, does not have a rectum. This contributes to frequent emptying, which reduces the mass of birds and facilitates the flight. Fakes are liquid, as they are mixed with urine in a cloake. There are vegetative, insectivorous, birds of prey.
Respiratory system. Respiratory organs - air pathways (nostrils, nose cavity, throat, larynx, trachea, bronchi), light, air bags (extended bronchi). Lights - small dense spongy bodies that do not have a common inner cavity, like reptiles. The respiratory tract begins the nostrils leading to the nasal cavity. The internal breathing holes (joans) open into the oral cavity, then the respiratory tract continues to the uppermost larynx, the trachea and the lower (singing) larynx. The lower part of the trachea is divided into two bronons included in the lungs. Bronchi branch and form bronchiolesin which gas exchange occurs. Part of the bronchi goes beyond the limits of lungs and forms 5 pairs of thin-walled increases - aerial bags. They are located between organs and muscles, under the skin and in tubular bones. Air bags: Temporary air tanks, Ensuring light ventilation, overheating protection in flight. At rest, respiratory movements are carried out only at the expense of the chest. In flight, breathing is associated with the movements of the wings. When climbing the wings (inhalation), the air enters the lungs, partially gives oxygen and passes into air bags. In air bags of blood oxidation does not occur. When lowering the wings (exhalation), the air from the bags is entered into the lungs. Blood is oxidized in the lungs, both inhaling and with exhalation. Such breathing got a name dual.
Circulatory system Closed, two circles of blood circulation, full separation of arterial and venous blood. A heart quadrochmerconsists of two atrial and two ventricles. A large circle of blood circulation begins in the left ventricle, from which he leaves the right arc of aorta, branched on the set of smaller arteries that carry arterial blood to all organs and tissues. Viennic blood is assembled in hollow veins flowing into the right atrium, where a large circle of blood circulation ends. A small circle of blood circulation begins on the right ventricle with a moile trunk, according to which the venous blood flows to the slight. Oxidized arterial blood flows to the left atrium on the pulmonary veins. Temperature of body high (42-43.5 ° C) and constant (homoothermic organisms). The pulse is about 165, and in flight in small birds up to 1000 beats per minute. It is characterized by a high level of metabolic processes and good thermoregulation.
Selective system. Allocation bodies - paired secondary (pelvic) kidneys, no bladder, urine flows through the ureters in Cloaca. The end product of the metabolism is urinary acid.
Nervous system consists of central and peripheral. The central nervous system includes a head and spinal cord. In the brain of 5 departments: oblong, cerebellum, medium, intermediate and front. The most developed front brain. His progressive development causes a more complex behavior of birds. The visual shares of the medium brain and the cerebellum coordinating the complex movements of birds are well developed. The spinal cord has smaller dimensions due to the instance of the vertebrae and the formation of the tailbone. 12 pairs of accelera brain nerves depart from the brain.
Sense organs.Especially well developed vision. The eyes are large, equipped with the upper and lower eyelids and a blinking metering (third century). Vision color. Big visual acuity is provided double accommodation: change in the curvature of the lens and the distance between the lens and the retina (shape of the eyeball). The hearing body contains inner and secondary ear with one hearing bone and eardrum. An outdoor ear appears in the form of an outdoor auditory passage. Slim rumors have predatory night birds (Owl, Philin). The function of the ear shells is performed by movable ear feathers. The function of the touch is performed by the nerve endings in the skin. They perceive pain and temperature changes. The sense of smell is weak. Taste receptors are located in birds in the language and walls of the oral cavity.
Reproduction and development. All birds separately. The females of the two ovaries and the ovidifiers are developed only left (right ovary and ovagidel, as a rule, reduced). The ovage opens in a clock. The male couples and seeds opened in Cloaca. By the reproduction period, the seeds increase in size in 1 thousand and more than once. By the time of the achievement of puberty, signs of sexual dimorphism are developing. In the marriage, marriage games and vapor education are characteristic. The reproduction of sex. Seamation internal. Birds - egg-owned. In the center of the egg there is a yolk with a germ diskette (actually an egg cell), shells surround: protein, two suggestions (form an air chamber), shell (consists of calcium salts), the sorry (formed in the genital female). Fertilized eggs are postponed in nestwhere they are developing under the influence of the parents of parents (based). Parents also protect the nest from enemies, feed, guard and raise chicks. Development direct. The embryo is developing in the egg.
Fixtures of birds for flight: Wings, a streamlined form, lightweight skeleton (hollow bones filled with air), the presence of a keel, the fire of the foot and brushes, the reduction of the fingers, the development of the breast muscles, air bags, the absence of jaws, teeth, rectum, bladder, right ovary and ovarian, double Breathing, double accommodation, intense metabolism, constantly high body temperature, etc.
Origin and aromorphosis. Birds occurred from the ancient reptiles ( pseudozehi) In the Triassic (Jurassic) period of the Mesozoic era. Transitional form between reptiles and birds - archeopteryix. Detected as fossil residues. It has signs of reptiles (lack of beak, the presence of teeth, breast without keel) and signs of birds (wings, plumage, struck the clavicle). The appearance of birds contributed to the following aromorphoses: the appearance of a four-dimensional heart; Full separation of arterial and venous blood; constant body temperature and perfect thermoregulation; Differentiation of respiratory tract.
Value. Birds play an important role in the spread of fruits and seeds (droinds, cedings, swelling, sitting), in the regulation of the number of insects, rodents, etc. (predatory, sparrows), pollination of plants (Hummingbird, nekthnica), destroying animals of remnants (vultures, vultures) . A number of birds damage to a person, damaging cereal crops, fruits and berries in the gardens (crows, sparrows). Some are the object of hunting (wild ducks, geese, pleahari). Running poultry, man gets eggs, meat, feathers, fluff (chickens, ducks, geese, turkey).
Security. From the beginning of the XVII century. More than 90 species of birds have died out. The number of many species is rapidly declining, many are under threat of disappearance (gray crane, white and gray herons, storks, flamingo, etc.).
Systematics and classification. The class of birds includes supervisors: penguins, pileless and quiley.
Penguins (Imperial, Adeli). Large size (up to 1 m). Live in Antarctica. Do not fly, but perfectly float with the help of wings converted to flippers. There is a keel. Stop is wide, which allows the penguins to "walk" in a vertical position. The plumage is unmatched, resembles a fur. Live big colonies.
Overcarriage (Ostrich, Nanda, Casual, Emu, Kiwi). Do not fly, but quickly run. Large sizes. Loss of ability to flight caused atrophy of keel sternum. They are usually in open places where there is the possibility of rapid movement on the ground. Due to the adaptation to the rapid run, the number of fingers has decreased to three or two.
Kel's outstanding (chicken, goose, sparrows, pigeons, predatory). Kiel is well developed. Most representatives are able to fly. Completed in all geographic areas: from the Arctic to Antarctic. Meet in various habitats.
Systematic classification is made according to the principle of kinship between groups. But the diversity of birds consists not only in differences in systematic signs, but also by the characteristics of the structure, lifestyle, developed in connection with the adaptations to various habitats.
At the place of habitat Several groups of birds are distinguished: woodstuffs Birds mining food on trees (dyatlah, rapides, food, vertical), nesting on trees, hunting in the air (mukholovka, hawks), mining food on trees and on earth, but nesting and nightly on earth (Ryabchiki, Tewerieva); swamp-meadow birds inhabiting wetlands, moss swamps, thickets of reeds (herons, cranes, storks) and climbing marsh birds (Korostela, Chefs); birds Oven (kulik-stilt, stone school); stepno-deserted (Drops, Strepps, Ostrichs); land-water (ducks, geese, swans), etc.
According to attachment to the territory Allocate groups: settled (Sparrows), koom (bullfinch), freight (cranes).
In places and methods of nesting: Some nest on Earth, others - on the branches of trees and shrubs, the third - in the dupes, in various shelters; Gnobs are invalid with dense walls, spherical with dense walls and velocity, and there are very simple - a fossa in a fatty or in the soil in a meadow with rare edges and several feathers and others.
By type of chicks distinguish chicken and broods birds. At the first chicks, hatching out of the egg, long remain helpless and need warming, feeding, protection. The chicks include all the sparrows, predatory and others. At the brood birds, the chicks, having soldered, are ready to follow their parents and feed themselves. The broods are tether, pleahari, quail, chickens, hills, etc.

Mammal Class (Beasts)

Mammals are the most highly organized vertebrates. There are more than 4500 species of mammals. Distributed very widely: inhabit all the continents, the sea and oceans. Habitat: ground-air, water, soil. Depending on the habitat, the following ecological groups of mammals are distinguished: ground, underground, wood, flying and water. The sizes of the body from 3 cm with a mass of 1.2 g (dwarfisheus) to 33 m with a mass of up to 150 tons (blue whale).
Structure. Body departments: Head, neck, torso, tail, front and hind limbs located under the body.
Pokrov Body Writing the skin, which consists of multilayer epidermis and dermis. Derma (actually leather) is formed by a connective tissue. The lower layer forms subcutaneous fat tissue. The resumption of the epidermis occurs due to the division of the cells of the spacing layer. The upper layers are buried. Epidermis derivatives: hair, vibriors ("mustache" of predatory, lastonous, rodents), bristles in pig, needles at hedgehog, horny plates (armadiors), horns (mannocardinary), claws (predators), nails (primates), hoofs (hoofs) . All mammals, except for some aquatic animals (whales, dolphins), have hair Pokrov; Eye eyes are equipped eyelashes. Hair has a rod and root located in the hair bag. Long hair - ost, short hair - undercoat. Skin derivatives are glands: sweat, greasy, odorous, moss. Milky and odorous glands are modified sweat.
Skeleton Consists of 3 parts: the skeleton of the head, the skeleton of the body and the skeleton of the limbs and their belts. Skeleton head (skull) Movingly connected to the spine with two mysteries. All have a big cranial box. The facial department prevails over the brain (elimination person). A well-developed bone palate separating the nasal passage from the oral cavity. Spine It consists of 5 departments: cervical (always 7 vertebrae), chest (9-24), lumbar (2-9), sacral (4-9) and tail (3-40). Breast vertebrae has ribs, which in the front of the sternum and form the chest. Sleepy vertebrae is articulated with pelvic bones. The skeleton of the belt of the front limbs is formed by paired blades and clavicle, the skeleton of the belt of the hind limbs - the pelvic bones. Free limbs: front - shoulder, forearm (from the elbow and radiation bones) and a brush (wrist, peel, phalange of the fingers), the rear is the thigh, the shin (from the big and small berth bone) and the foot (replous, plus and the phalange of the fingers). Catto-shaped rear limbs belt.
Muscular system Well differentiated, the muscles of the back, limbs and their belts are most developed. Muscular appears diaphragmwhich divides the secondary body cavity to the chest and abdominal. The muscles of the oars are appear.
Digestive system. Mouth, throat, esophagus, stomach, small intestine, blind intestine, thick intestine, anal hole. Digestive glands: salivary glands, liver, pancreas. There are lips, language. Teeth are differentiated on the cutters, fangs and indigenous teeth. Some have lost their teeth (musicals, toothless whales). The mouth cavity is separated from the nasal and soft naba, so the breath does not interfere with chewing food. The vegetative intestine is longer than that of predatory, and the blind intestine is well developed. Nutrition is characterized by a large variety.
Respiratory system comprises respiratory tract (nasal cavity, nasopharynk, larynx, trachea, bronchi, bronchioles) and pairs of lungs alveolar structure. The air enters the nostrils into the nasal cavity and through the homoans in the nasopharynx, and not into the oral cavity, like all other land vertebrates. Next, the air goes to the larynx, the trachea and bronchi. Branching bronchi form bronchial tree. At the ends of the smallest bronchioles are small bubbles ( alveola), whose walls consist of one-layer epithelium and thick capillaries. They take gas exchange. Thanks to the alveolar structure, the lungs have a very large area of \u200b\u200bthe respiratory surface. The respiratory movements occur due to the reduction of interrochemical muscles and diaphragms.
Circulatory system Closed, two circles of blood circulation and the complete separation of arterial and venous blood. The heart is four-dimensional - two atrium and two ventricles. In the right side of the heart - venous blood, in the left side - arterial. From the left ventricle leaves left arc aorta. The rest of the blood system of mammals corresponds to such in birds. Body temperature Permanent (homoothermal animals).
Selective system. Paired secondary (pelvic) kidneys, paired ureters, bladder and urethra. Mammalian kidneys have a greater number of vascular gloms and longer renal tubules compared to the kidneys of reptiles. End product exchange - urea.
The more advanced blood, respiratory, digestive and excretory systems provide a high level of metabolism and warm-bloodedness; Motor activity and protective hair (or subcutaneous fat) helps maintain high and constant body temperature.
Nervous system. Central and peripheral. Central nervous system - head and spinal cord. The brain has 5 departments: oblong, cerebellum, medium, intermediate and front. All of them are well developed. The leading role is played well developed bark of front brain . Many it has furrows and gyrusincreasing its surface. Along with complex instincts, the behavior of mammals basically determine the conditional reflexes. Higher mammals have dades. The peripheral nervous system is represented by 12 vapors of the cranial brain nerves, spinal brain nerves and nervous plexuses.
Sense organs. Bodies of vision - eyes. Developed weaker than birds. Vision binocular (volume). Some species (primates) have color vision. Touch bodies - leather, mustache, vibriors (sensitive hairs). Taste organ - language. The sense of smell is the nasal cavity receptors (the most developed organ of feelings of many mammals). Hearing organ and equilibrium - Ear. The ear has three departments: outer (auditory passage and ear sink), average (three auditory bones: dying, anvil and hammer), internal. For some mammals (dolphins, bats) are characterized by echolocation (orientation with ultrasound).
Reproduction and development. Separation. Sexual dimorphism. Floor glands. File female females are differentiated on eggs, uterus (uterus) and vagina. In males of many species, the seeds are not located in the abdominal cavity, but in a special external genital organ - scrotum. The seeds end in a seedweight channel passing inside the copulative organ - penis. Extra glands that allocate secrets that form a seed fluid appear. In males, the seed insulatory canal is both urethra. In females, the vagina opens into an external environment with an independent hole. With the exception of several types of egg-owned overwhelming majority of mammals. Eggs have minor sizes and contain a small amount of nutrients. Seamation internal. Fertilization occurs in the eggs. The embryo is immersed in the mucous membrane of the uterus. Its nutrition, breathing and allocation of exchange products in most mammals occurs through placet. Arnion forming an aquatic environment for development is formed around the embryo. The fruit for a certain period develops in the uterus (intrauterine development). The duration of pregnancy in large species of about a year, in mice-like rodents 2 weeks. After the birth of the female fucks baby milk. The number of cubs from 1 to 20. Caring for offspring is expressed.
Value. In nature, mammals participate in pollination of plants (manochable), the spread of their seeds (vegetative), are "sanitary" nature "of nature (predators and padals). Mammals have a huge economic importance for a person. Most agricultural animals belong to the class of mammals: they give milk, meat, wool, skin (large and small cattle). Some species serve as a subject of fishing and sports hunting (wild boars, deer, moose, hares). Many are pests of agriculture (tiny rodents, predators). Some pose a threat to human health, as they can be carriers of various diseases - Foxhra, rabies, brucellosis, pork ascarides, etc. (rodents, hoofs, stray dogs). Many species of mammals are used as experimental animals (dogs, mice, rats, guinea pigs).
Origin and aromorphosis. Mammals occurred from the ancient reptiles in the Triassic period of the Mesozoic era. Transition forms - morning lizards - We had skin glands, weak epidermis oroging, the location of the hind limbs under the torso, differentiated teeth. The occurrence of the mammalian class was facilitated by the following aromorphoses: highly developed bark of large hemispheres of the front brain, intrauterine development, feeding of cubs with milk, hair cover, four-dimensional heart and the full separation of arterial and venous blood, warm-bloodedness, lightweight alveolar structure.
Systematics. The mammalian class is divided into subclasses: prevmery (egg-owned, cloth), the shortcuts (lower beasts), placental (higher beasts). The class includes more than 20 detachments.
Promoter subclass (egg-owned, clical) - The most primitive of living mammals. The subclass includes one detachment - a detachment of single-pass (installation, echidnas). They have some features of reptiles - there is a clock, the ravene dice, the body temperature is non-permanent (ranges from 25 to 36 ° C), they lay eggs (cliffs are sitting on eggs, the echids are carrying eggs in the bag - the skin folds on the abdomen). At the same time, their body is covered with wool, cubs are fed up with milk. Milk glands without nipples and their ducts open on glandular skin fields. The females have only one, left ovary. Human surges in Australia, Tasmania, New Guinea. Wrockpoint leads a semi-water lifestyle, feeds in malicious. Echidna lives on land, eating ants and other insects.
Subclass of the sample (lower beasts). Temples do not have placenta, or it is developed weakly. Therefore, they give rise to underdeveloped cubs, who are hampered in the bag on the stomach, feeding the milk. There are a kangaroo, short-grades, samp bearings (koala), short-gravy muscles, sample moles, possas, and others. They live in Australia and on the adjacent islands, and some (OPOSSUMS) in South and North America.
Subclass of placental (higher beasts) - The most highly organized mammals. Their cubs at the time of birth reaches more complete development than that of the samples. The duration of the development of the embryo inside the mother's body depends on the size of the animals and can last from several weeks (mice) to two years (elephants). Baby are born capable of self-made milk. Machine breasts have well-developed nipples. Teeth, as a rule, are well differentiated to the cutters, fangs and indigenous. Milk teeth are replaced by constant teeth. Cloaca is not.
The placental subclass includes detachments: insectivores, manochable, rodents, hazing, predatory, laston-either, cetacean, man-foste, nonposable, primates.
The squad insectivores. The most primitive subclass of higher animals. It includes hedgehogs, moles, earthling, outcrows. The brain department of the skull is small. The front head of the head is pulled into the trot. Teeth differentiated weakly. The limbs are permanent. The brain does not have the convolution. Most are active at night, part - the clock day. Distributed everywhere, except Australia, Antarctic and most of South America.
The detachment is manochable. The only group of mammals capable of flight. These include Krylov, volatile mice, vampires. Distributed everywhere, excluding only polar areas and some oceanic islands. The wings are formed by the leather membrane, stretched between the long fingers of the front limbs (the first finger remains free), the mills of bones and forearm, the sides of the body, the rear limbs and the tail, if it is. There is a keel on his chest to which breast muscles are attached. The hind limbs are deployed by knee joints to the sides. Lead twilight and nightlife. Very subtle rumor. Oriented in flight with ultrasound.
The step volatile mouse . Representatives: Redhead and Small Sunny, Ears, Leather and others. Vision is poorly developed. They have perfect echolocation (sound signals generate a larynx). The teeth are insectivorous type. Most insectivores, there are bloodsows, fishing, fronewomen. Asylums serve as caves, hollow trees, cracked rocks, man buildings.
Crightess of the Wellane . Representatives: volatile dogs, volatile foxes, etc. These are large animals - the length of the body is 6-40 cm, the scope of the wings 24-170 cm. Eyes are well developed, the vision is sharp. Dwell in the tropics. In the afternoon they sleep, hanging down her head and wrapped in wings, usually in crowns of trees, less often in caves, cracked rocks. Live with the colonies (sometimes several thousand individuals). Feed mainly juice and pulp fruit, often harm gardening.
Rodent squad. The most numerous and common detachment of mammals - includes over 30 families, 1/3 of all kinds of mammals. Rodents include families: Belicheski, flying, dickery, beavers, tushkars, choppers, mouse, etc.
Have two pairs of highly enlarged incisors, which are constantly growing and self-sharpened. In front of the cutters are covered with a thick layer of enamel, so do not stupid even from hard food. No fangs. Between the incisors and the root teeth, the lapse (diasthemia). The intestine is long, the blind intestine is strongly developed. Hemisphere brain is usually smooth. The thermoregulation is imperfect. Very fruitful. Lifestyle: woody (proteins, sony, flying), semi-water (beavers, nutria, ondatras), semi-oxide (mouse, rats). Mostly roasting.
Biocenoses are consultations of the first order. Many rodents are pests of agriculture (destroy cultural plants, meadow plants, bread and other foodstuffs). Some are carriers of causative agents of diseases (Susliki, Rats, Surki). Proteins, ondatras and some others - objects of fur fishery. Some rodents are bred in conditions of cellular and semi-power maintenance (nutria, ondatras, chinchillas).
Detachment Town-shaped. This detachment includes families: food and hares. The dental system is similar to such rodents. Two pairs of cutters in the upper jaw. No fangs. The cutters are separated from indigenous teeth by deprived of the teeth with space.
Detachment is predatory. The predatory includes families: doggy, raccoons, bears, kuni, cats, hyenas, etc. are common everywhere, excluding Australia and Antarctica (Australia has acclimatized species, such as wild Dingo dog).
They have small incisors, well-developed fangs with pointed peaks and indigenous teeth - tuberculous, often with cutting edges. The last surface tooth of the upper jaw and the first root bottom is highlighted by large sizes and cutting edges - these are so-called predatory teeth. Most predators are porous. Well developed hair cover. The clavicle is rudimentary or missing.
Lifestyle: single and family, mainly monoga. Active mainly at twilight and at night. Carnivorous, less often omnivorous.
In biocenoses, as a rule, are second-order consultations, regulate the number of herbivores. Some (wolves, foxes) are rabies distributors. Attacking pets, harm animal husbandry. Many predatory - valuable fishery facilities, as well as cellular breeding (mink, sable, Chernoburai Fox, scribe).
Detachment of lastonodi. Includes 3 families: eared seals (sea seals, sea lions, sivuchi), real seals (Greenland seals, seals Ordinary, nerves, sea elephants), walruses (one type of walrus).
Large sea predators. Well adapted to life in water. The body is spinged, the shape of the streamlined, the five-plated limbs are transformed into flippers, the tail is short, the clavicle is absent due to the monotonous movements of the limbs, the neck is shortened. There are a thick subcutaneous fat layer (up to 10 cm), which serves as a supply of nutrients, performs the function of thermal insulation, increases the buoyancy of the body. Hair cover in different species is developed to varying degrees. The teeth are predominantly conical, adapted only to setting the extraction and its deduction. From the senses organs, the most developed ear and smell.
Animals spend most of the time in water, leaving for a land or on leisure, reproduction and on the molting period. Laston-related - secondary animals, which is evidenced by the breath of atmospheric air, the overall plan of the structure of the lastics and limbs of ground mammals, periodic output to land (on the ice).
Catto-shaped squad. This detachment includes families of real whales, gray whales, polysya, dolphins, coushlots.
Catto-shaped, like a lastonous, - secondary mammals, but live in water all the time. The body is belonging, with a big head and with a horizontal two-sighted fin. The forelimbs turned into flippers. Hair, skin glands, hind limbs and pelvis are reduced. The subcutaneous fat layer is strongly developed. The respiratory nasal hole - the breath (one or two) is located on the theme and opens only at the moment of inhalation - exhalation. Large lungs. The high hemoglobin content in the blood and myoglobin in the muscles allow the whales to create reserves of oxygen and is under water for a long time (over an hour). The cubs are born in water (every two years). Typical smell is absent, but the chemorezenia is developed. The most developed ear of the senses. There are no shells. The tooth whales (coushlots, dolphins) are powered mainly by fish, challenged mollusks, messenger whales - mostly plankton crustaceans (filtering production with the help of whale oss). The salivary glands is not.
The number of most types of whales is reduced. The International Whale Commission establishes national quotas of the fishery of individual types of whales.
Detachment of manflock. The limbs fourparty - the third and fourth fingers are large and serve as a support, the axis of the limbs passes between them; The second and fifth fingers are weaker; The first finger is absent. The end phalanges of the fingers are covered with horny hooves. The clavicle is absent. Purbitivatory. The stomach in most species consists of several departments. Wide (in Australia and New Zealand are imported). Detachment of manflock is divided into suburbs: spherical, ruminants and caustic.
Digital leaps Includes families: pork, hippos. These are animals with massive torso and short legs. Purbitating or omnivorous, the stomach is simple, single-chamber - consists of one department.
Rubage juggling Include families: deer, cabg, gerium, giraffes, bulls. Purbitivatory. There are no incisors in the upper jaw, and often fangs. The indigenous teeth have a structure that contributes to coarse feeding. The stomach is multi-chamber, includes a scar, a grid, a book and a schuch - the stomach itself. Very long intestine. Food swallowed at the beginning into the scar, then fall into the grid with the cellular structure of the walls. Next, food is tightened back into the oral cavity, where the teeth of the ruminants are again peathed to the state of the liquid casher. After that, food again swallows and gets first in the book. In the walls of this department there are numerous folds. The book ends the digestion of fiber and food falls into the comma. Belings are digested under the action of gastric juice. Most of the ribbons have horns - headquartered bones. At the reindeer and females, and males with horns, at the elk female ruffes. Young horns (Pants) in some types of deer have healing importance. Many ruminants are domesticated (cows, sheep, goats).
Callogeneic follower. Representatives: camels, Lama. There are no real hooves. The limbs have two fingers. The bottom of the legs there are large elastic corrent pillows.
Dummy dispassing. This detachment includes families: tapir, rhinos, horses. The number of fingers on the front limbs 1 or 3, less than 4, and on the rear - 1 or 3. The third (average) finger carrying the bulk of the body is developed. The end phalanges of the fingers are covered with horny hooves. Purbitivatory. Indigenous teeth with transverse and longitudinal folds (adapted to food overs). Stomach simple. The clavicle is not.
Detachment Primates (monkeys). The most highly organized mammals. Primates belong to both a person. Eyes are awarded forward. The brain department of the skull is large, the hemispheres of the front brain is strongly developed with a large number of suts and furrows. Laptop limbs with the oppression of the thumb rest. Fingers have nails. One pair of dairy glasses on the chest. Monkeys inhabit tropical and subtropical forests. Basic wood lifestyle mainly.
The detachment is divided into two subdiges: lower primates (families: Tupay, Lemur, Lori) and higher primates (families: cappuchins, lower cloth, or monkey, and higher vocal, or man-like monkeys, people).
The family of man-like monkeys includes three major tailless views: orangutane, gorilla, chimpanzees. On many signs, they are closest to man. They have a naked face, small pasta sinks, stretching lips, are strongly developed by facial expressions, there is no tail and native bags. Can use some simple guns.
A family of people with one modern species is also included in the sub surveys of higher primates - a reasonable man.