Brief summary of the project
Hundreds of thousands of years ago, long before humans appeared on Earth, fish were already swimming in the oceans. At that time they were the most highly developed creatures.
Since then, they have developed in a variety of ways, so that now only a few species only remotely resemble the first primitive ocean fish.
Most fish use their tail as a motor. With his help and fins, they control their movements. Except for one species of fish, all the rest breathe with the help of gills. The fish swallows water through its mouth, which passes through the gills and pours out through a special hole. Water also contains oxygen, and it enters the blood of fish through the gills, like air through the lungs into the blood of a person.
In polluted water, fish try to float to the surface and breathe in air, but their gills are not adapted to absorb oxygen from the air.
The reason fish are dark on top and light below is to help them defend themselves against their enemies who, looking down, see the dark color blend into the water of a river or ocean. Looking from below, it seems that this is a light surface of the water. There are more than 20 thousand fish, and it's hard to imagine how much unique there is in the life of each!
Preschool age is the initial stage of the formation of the human personality. During this period, the foundations of personal culture are laid. During this period, the child learns to relate correctly to objects of nature, to things, materials of natural origin that he uses. Many children do not know at all and do not distinguish between fish, often found in water bodies (rivers, lakes). Within the framework of the project, children look at illustrations, purposefully observe fish in an aquarium, read about fish birds, stories, riddles. In the classroom, children establish cause-and-effect relationships, get acquainted with the concepts of "sea fish", "aquarium fish", "lake and river fish", identify the behavior of fish, the difficulties they experience in dirty water.
Project problem
Many believe that fish feel comfortable in any water, that this is a natural phenomenon. In fact, it is very difficult for fish to live in polluted water, because their gills are not adapted to absorb oxygen from the air. Therefore, we need to think about how to help the fish?
Questions guiding the project
Fundamental question: Pisces: who are they?
Problem Question: Do fish need water?
Cognitive questions: What is the importance of water in human life? How do fish adapt to life?
Objective of the project:
The formation in children of the ability for independent mental activity, the development of research abilities, the upbringing of a caring attitude and love for the natural environment.
Project objectives:
- Formation of the ability to observe, the ability to act independently;
- Attach to useful information;
- To develop creative activity in preschoolers;
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The project was prepared by: Kantsevich Anna Gennadievna
Project type: combinedProject duration: a week
search and cognitive
Brief summary of the project
Hundreds of thousands of years ago, long before humans appeared on Earth, fish were already swimming in the oceans. At that time they were the most highly developed creatures.
Since then, they have developed in a variety of ways, so that now only a few species only remotely resemble the first primitive ocean fish.
Most fish use their tail as a motor. With his help and fins, they control their movements. Except for one species of fish, all the rest breathe with the help of gills. The fish swallows water through its mouth, which passes through the gills and pours out through a special hole. Water also contains oxygen, and it enters the blood of fish through the gills, like air through the lungs into the blood of a person.
In polluted water, fish try to float to the surface and breathe in air, but their gills are not adapted to absorb oxygen from the air.
The reason fish are dark on top and light below is to help them defend themselves against their enemies who, looking down, see the dark color blend into the water of a river or ocean. Looking from below, it seems that this is a light surface of the water. There are more than 20 thousand fish, and it's hard to imagine how much unique there is in the life of each!
Preschool age is the initial stage of the formation of the human personality. During this period, the foundations of personal culture are laid. During this period, the child learns to treat objects of nature correctly, to things, materials of natural origin that he uses. Many children do not know at all and do not distinguish between fish, often found in water bodies (rivers, lakes). Within the framework of the project, children look at illustrations, purposefully observe fish in an aquarium, read about fish birds, stories, riddles. In the classroom, children establish cause-and-effect relationships, get acquainted with the concepts of "sea fish", "aquarium fish", "lake and river fish", identify the behavior of fish, the difficulties they experience in dirty water.
Project problem
Many believe that fish feel comfortable in any water, that this is a natural phenomenon. In fact, it is very difficult for fish to live in polluted water, because their gills are not adapted to absorb oxygen from the air. Therefore, we need to think about how to help the fish?
Questions guiding the project
Fundamental question: Pisces: who are they?
Problem Question: Do fish need water?
Cognitive questions: What is the importance of water in human life? How do fish adapt to life?
Objective of the project:
The formation in children of the ability for independent mental activity, the development of research abilities, the upbringing of a caring attitude and love for the natural environment.
Project objectives:
- Formation of the ability to observe, the ability to act independently;
- Attach to useful information;
- To develop creative activity in preschoolers;
First day
MORNING | WALK | EVENING | WALK |
| outdoor games
Word game "I know five river fish ..." - activation of the dictionary (names of fish) |
| Outdoor games
ball games |
Second day
MORNING | WALK | EVENING | WALK |
| outdoor games
Conversation: "If I were a fish ..." |
| Outdoor games
|
The third day
MORNING | WALK | EVENING | WALK |
| outdoor games
Drawing with sticks in the sand "Whose fish is better?" |
| Outdoor games
ball games |
The gills are the main part of the respiratory system of fish. It is thanks to them that the bulk of oxygen enters the blood, and carbon dioxide is released from the blood. However, gas exchange in fish occurs not only through the gills. In all species, the skin takes part in respiration. But at the same time, in species living in water bodies with a high oxygen content, breathing through the skin is insignificant. And in fish that live in conditions of oxygen deficiency (catfish, carps, eels), skin gas exchange can occupy a significant part of respiration. Also, in bony fish, a small amount of gas exchange occurs in the swim bladder. In lungfish fish, the swim bladder even changed into a cellular lung, so they can breathe not only in water, but also in air.
Describing the respiratory system of fish, they usually consider the structure of their gill apparatus, which is located in the pharynx. Gills are made up of gill slits supporting them gill arches, gill filaments And gill rakers. In bony fish, the obligatory structure of the respiratory system is also a pair gill covers. They protect the gills from getting foreign particles there. protective function perform and gill rakers. They are turned towards the pharynx and protect the thin and delicate gill filaments from particles from entering them from the pharynx. Gas exchange takes place in the gill filaments. Therefore, they can be considered the most important part of the respiratory system of fish. In many highly evolved fish, the gill filaments seem to branch (on the primary gill filaments, the secondary gill plates are perpendicular). This increases the total surface of the petals, and hence the area of the body of the fish, on which gas exchange occurs.
The respiratory system of fish can also include a network of blood vessels that bring venous blood to the gills and divert arterial blood from the gills. In the gill filaments, the blood vessels break up into a network of small capillaries close to the surface. It is here that gas exchange takes place (oxygen enters the blood from water, and carbon dioxide is released from the blood into water).
The mechanism of respiration in bony fish is as follows. When inhaling (while the fish lifts the gill covers), water enters the mouth, then it reaches the pharynx and when exhaling, which is carried out by contracting the muscles of the pharynx and pressing the gill covers to the body, it is pushed through the gill slits, washing the gill petals. When moving quickly, bony fish breathe passively (just like cartilaginous ones) without movement of the gill covers and muscle tension: water simply flows into the mouth and flows out of the gill slits.
Bony fish do not have the gill septa that cartilaginous fish have. Therefore, in bony fish, the gill filaments are located directly on the gill arches and are washed by water from all sides.
The respiratory system of bony fish is very efficient in that they absorb most of the oxygen from the water that has passed through their gills. This is important because water contains less oxygen than air.
The respiratory system in fish
Diagram of the respiratory systemfish The main respiratory organ of fish is the gills. At
cartilaginous fish gill slits have partitions,
due to which the gills open outward
separate holes. This is easy to see in
example of sharks or rays. On front and back
the walls of these septa contain gills
petals, which are covered with a dense network of circulatory
vessels. Bony fish, unlike cartilaginous fish, have movable bony gills.
lids, and their interbranchial septa are reduced. Gill filaments
in such fish they are found in pairs on the gill arches.
Gas exchange during respiration occurs with the participation of blood vessels on
gill petals. In addition to carbon dioxide, out through the gills can
other metabolic products, such as ammonia and
urea. Gills are also involved in salt and water metabolism. In lungfish fish, an additional respiratory organ is
swim bladder. It performs the functions of a lung.
The swim bladder is an organ found in almost all species.
fish, it is formed at the stage of embryonic development and
located in the dorsal part of the body of the fish. Depending on the features
bubble exist open-bubble fish species (bubble all life
associated with the pharynx) and closed bladder fish species (connection of the bladder with the pharynx
lost during development. The main function of the swim bladder
- hydrostatic. With the help of the bubble, the fish can regulate its
specific gravity, as well as the depth of immersion.
Due to the fact that every creature is endowed with everything, we get something without which we cannot live - oxygen. In all land animals and humans, these organs are called lungs, which absorb the maximum amount of oxygen from the air. fish, on the other hand, consists of gills that draw oxygen into the body from the water, where it is much less than in the air. It is because of this that the structure of the body of this biological species is so different from all backbone terrestrial creatures. Well, let's consider all the structural features of fish, their respiratory system and other vital organs.
Briefly about fish
To begin with, let's try to figure out what kind of creatures they are, how and with what they live, what kind of relationship they have with a person. Therefore, now we begin our biology lesson, the topic is "Sea fish". This is a superclass of vertebrates that live exclusively in the aquatic environment. A characteristic feature is that all fish are jawed and also have gills. It is worth noting that these indicators are typical for everyone, regardless of size and weight. In human life, this subclass plays an economically important role, since most of its representatives are eaten.
It is also believed that fish were at the dawn of evolution. It is these creatures that could live under water, but did not yet have jaws, were once the only inhabitants of the Earth. Since then, the species has evolved, some of them have turned into animals, some have remained under water. That's the whole lesson of biology. The topic "Sea fish. A brief excursion into history" is considered. The science that studies marine fish is called ichthyology. Let's now move on to the study of these creatures from a more professional point of view.
General scheme of the structure of fish
In general, we can say that the body of each fish is divided into three parts - the head, body and tail. The head ends in the region of the gills (at their beginning or end, depending on the superclass). The body ends on the line of the anus in all representatives of this class of marine life. The tail is the simplest part of the body, which consists of a rod and a fin.
The shape of the body strictly depends on the living conditions. Fish that lives in the middle water column (salmon, shark) has a torpedo-shaped figure, less often - swept. Those that float above the very bottom have a flattened shape. These include foxes and other fish that are forced to swim among plants or stones. They take on a more agile shape that has much in common with snakes. For example, an eel is the owner of a strongly elongated body.
Business card of a fish - its fins
Without fins, it is impossible to imagine the structure of a fish. Pictures that are presented even in children's books certainly show us this part of the body of marine inhabitants. What are they?
So, the fins are paired and unpaired. Pairs include chest and abdominal, which are symmetrical and move synchronously. Unpaired are presented in the form of a tail, dorsal fins (from one to three), as well as anal and adipose, which is located immediately behind the dorsal. The fins themselves are composed of hard and soft rays. It is on the basis of the number of these rays that the fin formula is calculated, which is used to determine a specific type of fish. The location of the fin is determined in Latin letters (A - anal, P - thoracic, V - ventral). Further, Roman numerals indicate the number of hard rays, and Arabic - soft.
Fish classification
Today, conditionally, all fish can be divided into two categories - cartilaginous and bone. The first group includes such inhabitants of the sea, the skeleton of which consists of their cartilage different size. This does not mean at all that such a creature is soft and incapable of movement. In many representatives of the superclass, cartilage hardens, and in its density becomes almost like bones. The second category is bony fish. Biology as a science claims that this superclass was the starting point of evolution. Once within its framework there was a long-extinct lobe-finned fish, from which, perhaps, all land mammals originated. Next, we will take a closer look at the structure of the body of the fish of each of these species.
cartilaginous
In principle, the structure is not something complicated and unusual. This is an ordinary skeleton, which consists of very hard and durable cartilage. Each compound is impregnated with calcium salts, thanks to which strength appears in cartilage. The notochord keeps its shape throughout life, while it is partially reduced. The skull is connected to the jaws, as a result of which the skeleton of the fish has an integral structure. Fins are also attached to it - caudal, paired ventral and pectoral. The jaws are located on the ventral side of the skeleton, and above them are two nostrils. The cartilaginous skeleton and muscular corset of such fish are covered on the outside with dense scales, which are called placoid. It consists of dentin, which is similar in composition to ordinary teeth in all terrestrial mammals.
How do cartilage breathe
The respiratory system of cartilage is represented primarily by gill slits. They number from 5 to 7 pairs on the body. Oxygen is distributed to the internal organs thanks to a spiral valve that stretches along the entire body of the fish. A characteristic feature of all cartilaginous is that they lack a swim bladder. That is why they are forced to constantly be in motion, so as not to go to the bottom. It is also important to note that the body of cartilaginous fish, which a priori live in salt waters, contains a minimal amount of this very salt. Scientists believe that this is due to the fact that this superclass has a lot of urea in the blood, which consists mainly of nitrogen.
Bone
Now let's look at what the skeleton of a fish that belongs to the superclass of bones looks like, and also find out what else is characteristic of representatives of this category.
So, the skeleton is presented in the form of a head, a torso (they exist separately, unlike the previous case), as well as paired and unpaired limbs. The cranium is divided into two sections - cerebral and visceral. The second includes the jaw and hyoid arches, which are the main components of the jaw apparatus. Also in the skeleton of bony fish there are gill arches that are designed to hold the gill apparatus. As for the muscles of this type of fish, they all have a segmental structure, and the most developed of them are the jaw, fin and gill.
Respiratory apparatus of bone inhabitants of the sea
Probably, it has already become clear to everyone that the respiratory system of bony fish mainly consists of gills. They are located on the gill arches. Gill slits are also an integral part of such fish. They are covered with a lid of the same name, which is designed so that the fish can breathe even in an immobilized state (unlike cartilaginous ones). Some representatives of the bone superclass can breathe through the skin. But those that live directly under the surface of the water, and at the same time never sink deeply, on the contrary, they capture air with their gills from the atmosphere, and not from the aquatic environment.
The structure of the gills
Gills are a unique organ that was previously inherent in all primary water creatures that lived on Earth. It is the process of gas exchange between the hydro-environment and the organism in which they function. The gills of the fish of our time are not much different from those gills that were inherent in the earlier inhabitants of our planet.
As a rule, they are presented in the form of two identical plates, which are penetrated by a very dense network of blood vessels. An integral part of the gills is the coelomic fluid. It is she who performs the process of gas exchange between the aquatic environment and the body of the fish. Note that this description of the respiratory system is inherent not only in fish, but in many vertebrate and non-vertebrate inhabitants of the seas and oceans. But about the fact that it is precisely those respiratory organs that are in the body of fish that are special in themselves, read on.
Where are the gills located
The respiratory system of fish is mostly concentrated in the pharynx. It is there that the gas exchange organs of the same name are located on which are fixed. They are presented in the form of petals that pass through themselves both air and various vital fluids that are inside each fish. In certain places, the pharynx is pierced by gill slits. It is through them that oxygen passes, which enters the mouth of the fish with the water it swallows.
A very important fact is that, compared to the body size of many marine life, their gills are quite large for them. In this regard, in their bodies there are problems with the osmolarity of the blood plasma. Because of this, fish always drink sea water and release it through the gill slits, thereby speeding up various metabolic processes. It has a lower consistency than blood, therefore it supplies the gills and other internal organs with oxygen faster and more efficiently.
The process of breathing
When a fish is just born, almost its entire body breathes. Blood vessels permeate each of its organs, including the outer shell, because the oxygen that is in sea water constantly penetrates into the body. Over time, each such individual begins to develop gill breathing, since it is the gills and all adjacent organs that are equipped with the largest network of blood vessels. This is where the fun begins. The breathing process of each fish depends on its anatomical features, therefore in ichthyology it is customary to divide it into two categories - active breathing and passive breathing. If everything is clear with the active one (the fish breathes “usually”, taking oxygen into the gills and processing it like a person), then we will now try to understand the passive one in more detail.
Passive breathing and what it depends on
This type of breathing is peculiar only to fast-moving inhabitants of the seas and oceans. As we said above, sharks, as well as some other representatives of the cartilaginous superclass, cannot be motionless for a long time, since they do not have a swim bladder. There is another reason for this, namely, this is passive breathing. When a fish swims at high speed, it opens its mouth and water automatically enters. Approaching the trachea and gills, oxygen is separated from the liquid, which nourishes the body of a marine fast-moving inhabitant. That is why, being without movement for a long time, the fish deprives itself of the opportunity to breathe, without spending any strength and energy on it. Finally, we note that such fast-moving inhabitants of salt waters include mainly sharks and all representatives of mackerels.
The main muscle of the fish body
A very simple fish is, which, we note, in the entire history of the existence of this class of animals, practically did not evolve. So, this body they have two chambers. It is represented by one main pump, which includes two chambers - the atrium and the ventricle. The fish heart pumps only venous blood. In principle, this type of marine life has a closed system. Blood circulates through all the capillaries of the gills, then merges in the vessels, and from there again diverges into smaller capillaries that already supply the rest of the internal organs. After that, the “waste” blood is collected in the veins (there are two of them in fish - hepatic and cardiac), from where it goes directly to the heart.
Conclusion
This is the end of our short biology lesson. The theme of fish, as it turned out, is very interesting, fascinating and simple. The organism of these inhabitants of the sea is extremely important for study, since it is believed that they were the first inhabitants of our planet, each of them is the key to unraveling evolution. In addition, studying the structure and functioning of a fish organism is much easier than any other. And the sizes of these inhabitants of the water stochia are quite acceptable for detailed consideration, and at the same time, all systems and formations are simple and accessible even for school-age children.
The respiratory system in fish
The consumption of oxygen and the release of carbon dioxide as a by-product is called the process of respiration. The main respiratory organs of fish are gills.
Fish have two sets of gills - one on each side of the body behind the head. These delicate organs are protected by hard plates called opercula.
Each set of gills includes four bony arches. Each of these arches supports two rows of feather-shaped gill fibers called primary lamellae (petals).
Each primary lamina, in turn, is lined with tiny lamellae (secondary lobes) through which narrow blood capillaries pass.
It is through the thin shell of the secondary lobes that gas exchange occurs between the blood and the external environment. The blood in the secondary lobes flows in the opposite direction to that of water flowing over the surfaces of the lamellae.
As a result, a large diffusion gradient of oxygen and carbon dioxide arises between these two liquids. This "counter-flow" system greatly increases the efficiency of gas exchange.
Respiratory system in amphibians.
The respiratory system of amphibians is represented by lungs and skin, through which they are also able to breathe. The lungs are paired hollow sacs with a cellular inner surface, which is dotted with capillaries. This is where gas exchange takes place. The mechanism of respiration in frogs is forced and cannot be called perfect. The frog draws air into the oropharyngeal cavity, which is achieved by lowering the floor of the mouth and opening the nostrils. Then the bottom of the mouth rises, and the nostrils are again closed with valves, and air is forced into the lungs.
Respiratory system in marine mammals.
Let's take a whale as an example.
The skull of whales is adapted so that breathing takes place when the nostrils are exposed from the water without bending the neck (the nostrils are shifted to the top of the head).
The maxillary, intermaxillary, and mandibular bones are elongated due to the development of the sieve apparatus (whalebone) or numerous unimodal teeth. The nasal bones are reduced, the parietals are shifted to the sides so that the superior occipital bone is in contact with the frontal.
The blowhole - one or two external nasal openings - is located at the top of the head and opens only at the moment of a short respiratory act of exhalation - inhalation, produced immediately after emerging. In cool weather, when exhaling, condensed steam flies up, forming a so-called fountain, by which whalers distinguish between the type of whale.
Sometimes atomized sprays of water also take off with this steam. The rest of the time, while the respiratory pause lasts and the animal dives, the nostrils are tightly closed with valves that do not allow water to enter. Airways. Due to the special structure of the larynx, the airway is separated from the food. This allows you to breathe safely if water or food is in your mouth. The nasal canal of most species is connected to special air sacs and together with them plays the role of a sound-signaling organ.
The lungs of cetaceans are very resilient and elastic, adapted to rapid contraction and expansion, which provides a very short respiratory act and allows you to renew the air in one breath by 80-90% (in humans, only 15%). In the lungs, the musculature of the alveoli and cartilaginous rings are strongly developed, even in small bronchi, and in dolphins - in bronchioles.
Cetaceans can stay under water for a long time (sperm whales and bottlenose up to 1.5 hours) with the same air supply: a large lung capacity and a rich content of muscle hemoglobin allow them to carry away an increased amount of oxygen from the surface, which is consumed very economically: during diving, activity the heart (pulse) slows down by more than half and the blood flow is redistributed so that oxygen is supplied primarily to the brain and heart muscle. During prolonged immersion, these organs also receive oxygen with arterial blood from the reserves of the "wonderful network" - the thinnest branching of blood vessels.
Tissues less sensitive to oxygen starvation (especially the muscles of the body) are transferred to starvation rations. Muscle hemoglobin, which gives the muscles a dark color, supplies the muscles with oxygen during the respiratory pause.