Teacher: Khokhlova I.V.Lesson in the development of oral speech in 4 "A" class
Topic:
Target: to acquaint children with the general signs of fish, structural features, nutrition, movement;
Tasks: R
Equipment:
Lesson type: learning new materialMethods: TechnologyLesson plan.
I. Organizational moment.Topic: Fish. What is the body of the fish covered with? How fish move, what and how they eat.
Target: to acquaint children with the general characteristics and diversity of fish, structural features, nutrition, movement;
Tasks: R to develop the cognitive activity of students,the ability to coordinate words, write a description of the subject;to develop the ability of children to work with a textbook;correction of thinking based on the exercise in comparison,in classification, visual memory-based exercises in memorization; incultivate interest and respect for nature.
Equipment: subject pictures of river and sea fish, textbook, workbook, "Calendar of Nature", handout and didactic material, drawing of a bathyscaphe.
Lesson type: learning new materialMethods: verbal (conversation, frontal survey, posing a problematic question, working with a book); visual (subject pictures, demonstration, display), practical (exercises for collective and differentiated work) Technology: personality-oriented, correctional-developing, health-savingDuring the classes
Lesson stages
Guys, look at the guests, give them your smiles. A smile is the key to a good mood.- If you are in a good mood, smile at each other.If you want to enjoy the lesson, I ask you to be my active assistants, listen to me carefully, answer correctly and with complete answers.
The lesson starts.
He will go to the guys for the future.
Try to understand everything
Learn to unlock secrets
Give complete answers
And don't yawn in class.Memory correction exercise. Memorize as many items as possible.
Name the subject in the plural.
One crucian- a lot of crucian river - many rivers Perch - perch pike - pike
Development of auditory perception
b) Work with the Calendar of nature.Fizminutka.
Eye exercises.
Nouns agree with adjectives in gender, number and case.
Exercise in the selection of words-actions
Work in notebooks.
Corrective reception transferring the method of information to your individual task
An exercise in the selection of antonyms.
word formation exercise
Textbook work.
An exercise in agreeing numerals with nouns.
Today we will go on an underwater expedition, but I won’t tell you right away where. Guess yourself. Solve the riddle. Flowing - not leakingExpedition It is a journey with a specific mission. And we will go on an expedition on an underwater descent vehicle -bathyscaphe. It is designed to observe fish and study the river or seabed.Bathyscaphe - a small submarine, while on which you must follow certain rules:
Keep quiet. Be attentive. Answer the questions . Now close your eyesincludes an audio recording of the sound of the sea, the cry of seagulls ). Much research work to be done. What do you hear? Wind (what?) Strong, quiet, weak. Wave (what?) Fast, high, running. Look at the different fish.Fish ( what do they do?) (move, eat, multiply, grow, breathe)
Collect "shards". Let's take a look at them. - Look at the different types of fish. - Tell me, what parts do they consist of? We make an entry in the logbook.Form new words.
Fish - fish - fish.
Fin - fin - fin.
Tail - tail - tail.
Eye - eye - eye.
The fish swam in the sea
- not in dirty water, but ... (in clean),
- not slowly, but ... (quickly), swiftly.
- She herself was not simple, but ... (golden).
- Do the fish eat? What does it eat?
- Let's play the game "Replace two words for one"
Soup from fish ... (fish)
Fish cutlet ... (fish)
Fish pies ... (fish)
Fish pie ... (fish)
How do fish breathe in water?
Conclusion: fish breathe oxygen dissolved in water with the help of gills.
They multiply and grow (female fish spawn eggs,
- Babies of fish appear from ...? (calves)They're called …? (fry)
Why are baby fish called fry?
Fish development cycle- (caviar - fry - adult fish)
Exercise "Count.1 male, 10..., 15..., 25...
1 fish, 5..., 15...,...,25...
4)Life is very difficult for fish these days. And not because people catch and eat them, but because a person violates the habitat of fish. Do you know how a person violates the habitat of fish?
– Pollution of water bodies with industrial waste: oil and oil products (oil forms a film on the surface of the water that does not allow air to pass through, and the fish become unable to breathe);
– pollution from fertilizers that run off the fields;
– pollution with household waste and garbage.
We must learn to exist with nature and be its protectors. So what is our task?
We continue our traditional section Tips of experienced fishermen - today we present material explaining the structure and shape of the body of the fish, and its movements:
Navigation: About fish - organs, instincts
The structure of the body of fish and the shape of their body are adapted for living in water. Water is many times denser than air, and moving in it is not so easy. Gradually, over the course of many generations, the fish developed special devices that facilitate movement, and developed special techniques that allow them to swim easily and quickly. The mucus that covers the body of the fish greatly facilitates the movement. All fish are characterized by a streamlined body shape, gill breathing, and the presence of limbs in the form of fins. The most perfect form - spindle-shaped - in fish that make long voyages, ascending the river against the currents, or in fish that keep to the current. The body of this shape allows asp, trout and some other fish to easily overcome rapids and swim without getting tired for a long time.
Sedentary bottom fish have a rounded, thick body, sometimes flattened from top to bottom, and a darker color (catfish, burbot). And in fish that live in still water (bream, crucian carp, carp, roach, etc.), the body is compressed from the sides. This helps them move among aquatic plants and turn in a vertical plane.
In most fish, most often the pointed head imperceptibly (without a neck) passes into the body, and the latter into the tail section. The border between the head and the body is marked by the gill slits, and between the body and the caudal peduncle is the anus.
Fish differ in the position of the mouth. In a bream, for example, it is adapted to take food from the bottom (its mouth can even extend into a tube), in a pike, to grab prey, and in a sabrefish, which feeds on falling insects near the surface of the water, the mouth is upper. Carp teeth are located in the pharynx, they help them crush coarse food.
The body of the fish is equipped with fins: unpaired (dorsal and caudal) and paired (pectoral and ventral). Located on the back and under the tail are the keels. Forward forward movement is carried out by the caudal fin, as well as undulating body bends. Paired fins support the fish in a horizontal position and facilitate its turns (Fig. 1). In the movement of fish in the vertical direction, a swim bladder filled with gases is of great importance. A change in the volume of the swim bladder causes the fish to float or sink. But some species of fish do not have a swim bladder, therefore, in order to rise to the upper layers of the water, they have to make great efforts (for example, eels).
The color of the body of fish is always adapted to the color and light conditions of the reservoir. That is why sometimes the same species of fish has different shades of color in different bodies of water.
Fish living in thickets of aquatic plants have spots or transverse stripes on their bodies, making them less noticeable against the background of algae (perch, pike). Top-swimming fish are painted in dark colors from above, due to which they are poorly visible from above, where their constant enemies, birds, live. The silvery-white sides and belly mask the fish when viewed from below, from where predators can attack it. But the bottom fish have a dark color, merging with the background of the bottom.
Pisces are primary water organisms. They live in fresh and salt water bodies. Due to the fact that the aquatic habitat is very dense and viscous (the density of water is 800 times higher than the density of air, and the viscosity is 50 times higher than the viscosity of air), fish have streamlined form body, often laterally flattened.
It is convenient to consider the general scheme of the structure of fish using the example of a river perch - perca fluviatilis (type Chordates, subtype Vertebrates, superclass Fishes, class Bony fishes, order Perciformes). River perch is a commercial fish, widespread in fresh water bodies of Europe and Asia. Perch is a predatory fish that feeds on various invertebrates and fish, and often eats a large number of fry, so it can be harmful in places of fish breeding. Perch reach sexual maturity in their second year. Its spawning begins only after the disappearance of ice on water bodies. For some time before spawning, the color of perches becomes especially bright. They gather in flocks in backwaters, oxbow lakes and other places, shallow and without a current. Females spawn eggs, glued in the form of ribbons, on aquatic plants. Males at this time spew sperm. Motile spermatozoa swim up to the eggs and penetrate them. The complex instinctive behavior of fish during the breeding season is called spawning. The fertilized egg begins to divide. A multicellular embryo is formed, in which the yolk sac is visible on the ventral side - the remnant of the nutrient reserve of the egg. In perch, 9-14 days after fertilization, the larva leaves the shell of the egg and begins to feed independently, first on microorganisms, and then on small crustaceans and other animals suspended in the water column. After a while, the larva becomes similar to an adult perch - this is a fry. It grows relatively quickly: after about two months, its length reaches 2 cm, and after a year, the young perch has a length of about 10 cm. Perch caviar often dies from drying out, larvae and fry die from enemies. Only due to the fact that during spawning, the female perch spawns up to 300 thousand eggs, some of the offspring survive to adulthood.
The general scheme of the structure of fish using the example of river perch is shown in Figure 1. The different shape of the body of fish is shown in Figure 2.
The body of any fish is heads, torso and tail. The gill slit serves as the boundary between the head and the body, and the anus serves as the boundary between the body and the tail.
On the head in fish is located mouth, eyes, nostrils. The mouth of bony fish is located at the front end of the head, which is why such fish are called extremities,
General characteristics of fish
in cartilaginous fish, the mouth is broad, transversely located. On the sides of the head are large flat eyes. Ahead lie paired nostrils - the organs of smell. The nostrils open into the olfactory fossa and do not communicate with each other.
Bony fish have a bone branchial lid. In this regard, instead of five gill openings (as in cartilaginous fish), one gill slit is formed. Cartilaginous fish do not have a gill cover.
Rice. 1. Scheme of the structure of bony fish.
1 - brain; 2- eyes; 3 - olfactory pits; 4 - gills; 5 - heart; 6 - pectoral fin; 7- intestines; 8 - ventral fin; 9 - gonad; 10 - anus; 11 - anal fin; 12 - tail fin; 13 - dorsal fin; 14 - spine; 15 - kidney; 16 - swim bladder.
Rice. 2. Different fish body shape.
1 - torpedo shape (mackerel)
2 - arrow-shaped form (garfish)
3 - laterally flattened (bream)
4 - type of moon-fish (moon-fish)
5 - type of flounder (flounder)
6 - serpentine shape (eel)
7 - ribbon-like form (herring king)
8 - spherical shape (body)
9 - flat shape (slope).
General characteristics of fish
Limbs in aquatic fish fins. Paired fins (pectoral, ventral) are located in a vertical plane. The dorsal fins are equipped with soft branched and hard spiny rays. The rays are interconnected by a thin leathery membrane. On the underside of the body, closer to the posterior end, is the caudal or anal fin. In front of it, in a common recess, there are three openings: anal, genital and excretory - in bony fish, and in cartilaginous fish there is one cloacal opening.
Fins are divided into two groups: paired(thoracic, abdominal) provide turns, balance, slow movements; unpaired(dorsal, anal) provide stability when moving, the tail acts as a rudder.
A well-marked lateral line- the organ of orientation of fish.
The body of bony fishes is covered with bony (ganoid) scales, consisting of transparent bone plates. Each scale lies in a special pocket. The scales overlap each other in the form of a tile that protects the body of the fish. Cartilaginous fish have placoid scales, consisting of dentin. The structure of fish scales is shown in Figure 3.
Rice. 3. Fish scales.
I. placoid scales in cartilaginous fishes.
II. ganoid scales in bony fish:
1 - cycloid scales,
2 - ctenoid scales,
3 - the top of the scale,
4 - growth rings,
5 - the center of the scale.
General characteristics of fish
The body of the fish is covered slime, which promotes better movement in a dense aquatic environment, reduces friction when swimming and has bactericidal properties that prevent bacteria from penetrating the skin.
Skeleton bony fish - bone, and cartilaginous fish - cartilaginous. It is divided into sections: the axial skeleton (spine), the skeleton of the head (skull) and the skeleton of the limbs (fins).
Spine divided into two sections: trunk and tail. Consists of biconcave vertebrae, between which remains of the notochord are preserved. The trunk vertebra consists of the vertebral body, superior and inferior arches. The ends of the upper arches grow together, forming the spinal canal, and end with a long unpaired spinous process. The lower arches grow to the sides in the form of two transverse processes, to which long and thin ribs are attached. The caudal vertebrae have well-defined lower arches that form the hemal canal and end with the lower spinous process. Blood vessels pass through the hemal canal. Ribs are missing. The vertebrae are connected to each other by articular processes located at the base of the upper arches. This connection provides the strength of the skeleton while maintaining its mobility. Actively swimming fish always have a developed spine. The vertebral column in fish is fixedly connected to the skull.
Scull fish consists of a large number of bones: the brain (cranial) box, jaw bones, gill arches and gill covers.
Skeleton limbs includes belt and skeleton of free limbs. The primary shoulder girdle is represented by the scapula and coracoid (corvium). From above, a large crescent-shaped bone with an elongated, pointed process, the kleitrum, is attached to it. With the help of two small bones of the secondary girdle (supraclaytrum and posterior parietal bone), the shoulder girdle is motionlessly articulated with the skull. The pelvic girdle is simple and has the shape of a triangular bone. Attached to paired ventral fins. Lies in the thickness of the abdominal muscles and is not connected to the spine.
Skeleton free limbs(fins) consists of cartilaginous or bone rays covered with skin.
Mmuscular system consists of separate segments separated by connective tissue septa. Muscle groups appear (gill, muscles of paired fins). Muscle contractions provide bending of the spine and set the tail blade in motion.
nervous system consists of spinal cord and brain. The brain is represented by five sections: anterior, intermediate, middle, oblong and cerebellum. The olfactory lobes of the forebrain are well developed. The forebrain is small in size, the roof is epithelial and does not contain medulla.
General characteristics of fish
Optic nerves approach the diencephalon. Visual centers are well developed in the midbrain. The cerebellum is responsible for the coordination of movements and, due to complex movements in water, reaches a large size. In the medulla oblongata are the centers of regulation of the respiratory, circulatory, digestive systems, as well as the centers of the sense organs (hearing, lateral line). Ten pairs of cranial nerves emerge from the brain.
The sense organs of fish are diverse. . Flavoring receptors (organs of chemical sense) are located over the entire surface of the body - on the head, fins, in the pharynx, esophagus, and oral cavity. These receptors are important for finding and recognizing food. It has been experimentally established that fish can distinguish between bitter, salty, sour, sweet. Olfactory organs represented by paired blind olfactory sacs, on the dorsal side of the head, lined with olfactory epithelium. Paired external nostrils connect the cavities of these sacs with the external environment. There are no internal nostrils (choan). The olfactory organ allows fish to find a partner during the breeding season, to feel the approach of prey or danger. Organs of vision(eyes) are located on the sides of the head. Vision is monocular. The cornea is flat, the lens has a spherical (spherical) shape. Fish can only see at close range. The circular muscles of the pupil and lens are absent. Accommodation (change in focal length) occurs due to the movement of the lens towards the anterior chamber or away from it with the help of a process of the choroid (crescent process), which is attached to the back wall of the lens. The retina contains rods and cones (color vision). Organ of hearing and balance represented by the inner ear with three semicircular canals (an organ of balance) containing liquid with suspended solid crystals. Fish are able to produce and perceive various sounds in a wide range. The sound conductivity of fish body tissues is close to that of water, so sound waves are transmitted directly through the tissues. Lateral line (organ of touch)- an organ that perceives the direction, movement of water, its pressure and flow strength. This is a group of sensitive cells immersed in channels that pass under the skin and open to the surface of the body with holes.
Digestive system begins with a mouth opening limited by jaws with conical teeth (to capture and hold food). There is no real language. The roof of the oral cavity is the base of the skull (primary hard palate). The pharynx, pierced by gill slits, passes into a short esophagus, and then into a distensible stomach. The small intestine departs from it, forming a characteristic bend, after which the intestine stretches straight back (large intestine) and opens outwards in bony fish with an independent anus, and in cartilaginous fish into the cloacal cavity. In the initial part of the small intestine in bone fish there are blind outgrowths - pyloric appendages that perform the function of increasing the digestive surface of the intestine. Cartilaginous fish do not have pyloric appendages, but have a so-called spiral valve. Fish have a developed liver, gallbladder, pancreas is located in the intestinal loop.
General characteristics of fish
iron in the form of lobules. Separated from the anterior intestine swim bladder(outgrowth of the dorsal wall of the esophagus), filled with a mixture of gases. Its functions are: hydrostatic, gas exchange (partially), resonant (increasing the range of perceived sound waves). Cartilaginous fish do not have a swim bladder.
Respiratory system represented by gills, which consist of four pairs of gill arches. Gill rakers are located on the gill arches, which act as a filtering apparatus, as well as gill filaments, equipped with a dense network of capillaries. Water entering the pharynx through the mouth washes the gill filaments, in which gas exchange occurs (oxygen enters the blood and carbon dioxide is removed from it). The structure of the gills is shown in Figure 4.
Rice. 4. The structure of the respiratory organs of fish.
1 - gill arch,
2 - gill petals,
3 - gill rakers.
The act of breathing in bony fish is carried out by the movement of the gill covers: the fish lifts the gill cover, the gill membrane is pressed against the gill slit. As a result, a space with reduced pressure is formed, and water from the oropharyngeal cavity is sucked into the lateral gill cavity. When the gill cover is lowered, excess pressure is created, and water is pushed out through the external gill openings.
Fish may develop adaptations for using atmospheric oxygen: intestinal walls with blood vessels, outgrowths of the dorsal and
General characteristics of fish
ventral pharyngeal wall, swim bladder. Air breathing organs ensure the survival of individuals in heavily polluted water bodies, where the amount of oxygen in the water is reduced.
Circulatory system closed. One circle of blood circulation. On the ventral side is a two-chambered heart, consisting of an atrium and a ventricle, containing venous blood. Venous blood from the ventricle of the heart enters the abdominal aorta and then through the four afferent branchial arteries to the gills. In the gill filaments, the blood is saturated with oxygen and becomes arterial. Then the efferent branchial arteries flow into the roots of the aorta and further into the dorsal aorta, which carries blood to the head, muscles and all internal organs. Venous blood returns to the heart through the azygous caudal vein and through the paired posterior and anterior cardiac veins. The right posterior cardial vein passes through the kidneys without branching, while the left gives a network of capillaries. The portal system of the kidneys is developed only in the left kidney. The posterior cardial veins merge with the anterior ones to form the Cuvier ducts. The axillary vein passes through the liver and, breaking up there into capillaries, forms the portal system of the liver. The hepatic vein emerges from the liver, flowing, like the Cuvier ducts, into the venous sinus. Fish have red blood cells, white blood cells and platelets in their blood. Erythrocytes are oval in shape and contain nuclei.
excretory system It is represented by paired ribbon-like trunk kidneys (mesonephros, primary kidneys), located on the sides of the spine almost along the entire body cavity. The ureters depart from each kidney, merge into a common duct and flow into the bladder, which, with an independent opening of the urethra, opens behind the anus into the external environment in bony fish, and in cartilaginous, the opening of the urethra opens into the cloacal cavity. The kidneys excrete the products of nitrogen metabolism - urea dissolved in water. Ammonia is the main end product of nitrogen metabolism. It has a high toxicity, and its accumulation in the blood in high concentrations is undesirable, harmful to the body. Due to the solubility of ammonia in water, the excretion of metabolic products is possible through the gills and skin.
Sexual system. Dioecious. Sex glands are paired. Fertilization in bony fish is external. The development is direct. Caviar is rich in yolk, and subsequent development is carried out in the external environment. Fish are anamnias, i.e. vertebrates, whose embryos do not have special embryonic membranes, and their development takes place in an aquatic environment.
Features of reproduction of bony fish:
1. Most fish spawn (spawn) a large amount of eggs into the water, where it is fertilized and embryos develop (river perch). At the same time, a large number of eggs die in the early stages of development from predators or getting into unfavorable conditions. There are spawning
General characteristics of fish
migrations. Anadromous fish migrate from seas to rivers. Salmon - chum salmon, pink salmon - make a long journey from the sea to the rivers, where there is a favorable oxygen regime for the development of caviar. Some (river eel) swim to spawn from rivers to the seas.
2. Spawning a small amount of eggs, which, thanks to the care of offspring, has a better chance of survival (for example, a male three-spined stickleback builds nests, a male seahorse bears developing eggs in a special bag, etc.).
3. Oviparous (guppies, swordsmen) - larvae appear from the female genital tract, turning into fry during the transition to independent feeding.
In cartilaginous fish, fertilization is internal, eggs develop in the oviducts, and the number of embryos is not large.
Fish, being an element of biological diversity, are of great importance in nature as consumers of plant matter created in water. Fish are carriers of matter and energy through food chains. In addition, fish produce economically valuable products (meat, fat) and can be actively used by humans.
Fish as a biological group arose in the course of evolution on Earth in the Silurian of the Paleozoic era (435 - 400 million years ago). Already in the Devonian, they represented the dominant group of organisms in all types of water basins. Until now, only two branches of the evolution of fish have survived: cartilaginous and bony fish.
Subject: What is the body of the fish covered with. How fish move, what and how they eat.
Target: reinforce students' knowledge of fish.
Tasks:
Tutorials: to form students' idea of fish as a class of animals; Encourage students to write a narrative story.
Correction-developing: to form mental operations; develop auditory memory; expand and activate the active dictionary; to form the skills of dialogic and monologue speech.
Educational: to cultivate interest and love for nature.
What do living beings need to live, besides breathing? (food) What do fish eat?
Pay attention to the color of the fish scales. What can you say about her? (Color may vary).
In fish that live in the upper part of the water, the color is lighter. Fish that live at great depths have a darker coloration. Why is this happening? Why do fish need to be invisible? (To escape from enemies, to watch for the victim, etc.)
Look at perch. How are its scales colored? (She's striped). Why do you think? Remember what this type of coloring is called. (camouflage)
Teacher's story. Now let's talk about fish breeding. Some animals give birth to live young. Birds hatch chicks from eggs. And fish lay eggs. The eggs are like balls the size of a pinhead. The color of caviar in different types of fish is different: gray, black, orange. Fry emerge from the eggs. In summer, we observed flocks of fry on the river. They swim in shallow places where the water is well warmed up. Fry are often eaten by predatory fish. Those fry that survive will become adult fish.
Fishing is prohibited during the spawning period. Can you explain why?
Game "Ask and Guess"
One student takes out a picture of a fish from the envelope. The second tries to guess what kind of fish it is. Asking questions like “Where does this fish live?”, “What color is its scales?”
6. Work on compiling a story.
Guess the riddle:
“What is this at the Check mark:
thread on a stick,
Wand in hand
Thread in the river? (Fishing rod)
What is a fishing rod for?
Listen to the sentence "Kolya and Sasha went fishing." Try to convey this idea in other words. Now we will try to make a story about fishing. Word combinations and phrases from the textbook will help you.
7. Lexical exercises. Why should you fish? To eat fish, it must be cooked. What do they do with the fish? (fried, boiled soup or fish soup, canned, salted)
8. Homework. Complete tasks on page 119
9. The result of the lesson.
What animals are we talking about?
What new did you learn?
What seemed interesting?
10. Homework: Make up riddles about fish.
Most fish have scales covering their entire body, from head to tail. In some of their species, it is completely invisible. But that doesn't mean it doesn't exist. In such fish, it is located under the skin, in the form of bone formations. Such a scale is called reduced. It is present on the body of catfish, eel, burbot, sturgeon, sterlet.
What is a fish scale?
It can have both bone and cartilaginous structure. It consists of inorganic substances, such as, for example, carbonates, phosphates, mineral salts, rare earth elements, alkalis. There are also organics.
The chemical composition of the scales can be completely different. It all depends on the type of fish and the halo of their habitat. For example, cartilaginous individuals have placoid scales, while ray-finned individuals have ganoid scales. In bony fish, it is represented by separate scales superimposed on each other. Cosmoid scales cover the body of lobe-finned fish. From above it is covered with a special enamel called kosmin.
In all cases, the scales protect the body of the fish from damage, and in some species it serves as a supporting apparatus. The most ancient is the placoid scale. It covered the bodies of ancient marine life. Nowadays, it is present in sharks and stingrays. Such scales are in the form of small, neat rhombuses, with a spike in the central part. Inside them is connective tissue. Placoid scales are highly durable due to a special substance - dentin, present in its composition. In addition, each such scale has an outer, vitrodentine layer. This type of scale not only protects the body of the fish, but also is the basis of its muscle tissue.
Ganoid scales also look like diamond-shaped plates. Between themselves, they are connected in a special way, forming a single structure, in the form of a shell or separate rings. The composition of such scales includes ganoin, which covers its outer surface, and gives it high strength.
Cycloid scales are present in bony fish. The individual scales overlap each other to create a flexible yet incredibly durable outer layer. In addition, such scales significantly improve the hydrodynamics of the fish.
In addition to protective properties, scales have a number of unique features. In the same coelacanth, it has teeth that give it the appearance of a saw, and the so-called goldfish got its name due to its special color. You will not see scales on the body of an eel. But that doesn't mean it doesn't exist. He has it, but very small, and almost imperceptible. In any case, fish scales are nothing more than a skin formation that performs a protective function.
