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Reflexes characteristic of fish. Examples of motor reflexes

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Topic: “Formation of conditioned reflexes in aquarium fish»

All living beings are able to respond to changes in the external and internal environment, which helps them survive. The nature of the relationship between animals and their environment is determined by the level of development nervous system. The body's response to exposure external environment with the participation of the nervous system is called a reflex.

Acquaintance with the structural features of the nervous system in the seventh grade course begins with the study of fish. The nervous system of fish is represented by the brain and spinal cord. The anterior part of the fish brain is relatively small. The midbrain and its optic lobes are the most developed. Fish differentiate between the brightness of lighting, choosing places that are more suitable for a given species. Most fish also distinguish the color of an object. Fish distinguish red color especially well. The hearing organ of fish is represented only by the inner ear and consists of a labyrinth, including the vestibule and three semicircular canals located in three perpendicular planes. The diencephalon and cerebellum are well developed. This is due to the need for clear coordination of movements while swimming. The medulla oblongata passes into the spinal cord. Nerves that control the muscles of the body and fins extend from the spinal cord.

The development of the nervous system leads to a significant complication of all its departments. Outwardly, this manifests itself in the behavior of animals, which becomes more complex and multifaceted depending on the nature of the environmental influences on the body. The basis of all reactions of the body to irritation is a reflex. Acquired (conditioned) reflex - reactions with the help of which the body adapts to changing environmental conditions. Conditioned reflexes are formed throughout life. The formation of conditioned reflexes is the basis for teaching the body various skills and adaptations to a changing environment. Fish is the first animal studied in school in which the most primitive conditioned reflexes of a feeding nature can be formed. Various fish are suitable for these experiments, but the ability to learn is different types not the same.

A large amount of theoretical material has been accumulated on the behavior of fish. However, along with the fact that the number of works on the topic of conditioned reflex activity in fish is very large, there are practically no evolutionary systematic works on acquired forms of behavior within the class of fish, although they are used in similar studies for broader comparisons. That is why we were interested in the question of the development of conditioned reflexes in fish that are far from each other in systematic position.

The purpose of our work was to study and compare the rate of development of conditioned food reflexes to colored feeders (positive to red and negative to blue) in fish of different species, depending on their phylogenetic relationship.

In the process of achieving this goal, the following tasks were solved:

Study and analyze the literature on the peculiarities of the formation of conditioned reflexes in various types of aquarium fish;

Get acquainted with the structural features and physiology of the following types of aquarium fish: guppies, swordtails, speckled catfish;

To study and compare the rate of development of conditioned food reflexes to colored feeders (positive to red and negative to blue) in fish of different species, depending on their phylogenetic relationship;

To achieve the formation of conditioned reflexes in fish of different systematic categories.

This work was carried out in a classroom. In experiments on the study of conditioned reflex activity, fish of three species were used: one species from the suborder Catfish - the strong catfish, belonging to the family Calechtiidae, as well as two species of fish belonging to the family Poeciliidae - the swordtail (genus Xiphophorus) and guppies (genus Lebistes) .

The study with fish was carried out over two weeks. The experiment involved 10 fish: 3 guppies, 5 swordtails and 2 catfish. The fish were of different ages (fry and adults about one and a half years old), and the sex of the individuals was also taken into account. One aquarium with a volume of 20 liters was allocated for the experiment. Two feeders with different colors: red and blue. The action of red light was reinforced by food, the action of blue light remained without reinforcement. Small bloodworms were used as food (unconditioned stimulus). The duration of the conditioned stimulus (the color of the feeder) was 10 seconds. Feed was supplied at the 6th second in the presence of a red feeder. During the experiment, the time the fish entered the feeding area, the time the food was eaten, the time the fish left the area, and other behavioral features of the test individual were recorded.

The experiments were carried out for two weeks, twice a day at different hours: 07.30 - morning feeding, 15.00. - evening feeding. Fish that came to the feeding zone after the red feeder was supplied, but before the food was supplied, that is, before the 6th second, were considered trained.

Consistent repetition of this result indicated the development of a positive conditioned reflex to the color of the red feeder. Negative conditioned reflex it was considered exhausted if the fish, in the presence of a blue feeder, did not swim into the feeding zone until the 10th second inclusive.

Subsequently, we compared the results obtained from experiments with different fish and drew conclusions about the ability to learn, that is, the development of conditioned reflexes for each fish species studied. We also took into account the age and sex characteristics of the fish.

Thus, we came to the conclusion that a clear development of a conditioned reflex (positive for red and negative for blue) is observed under these experimental conditions only in male swordtails of the sexually mature period of development. The females of this fish species made mistakes during the morning feeding hours, but always arrived at the feeding zone on time.

In representatives of fish of the guppy species, the reflex was developed later than in swordtails. The fish's reaction to the red color of the feeder occurred approximately after the 10th day of feeding. Here the females were more active and trainable. The fish began to purposefully move towards the feeder, but swam into the feeding zone mainly after the 10th second. The fry have not developed a conditioned reflex: a complete lack of reaction to the red and blue colors of the feeders. Perhaps this age group of fish requires a longer period of time to develop such a reflex.

We can talk about the absence of any reaction to the red and blue colors of the feeder in the speckled catfish. Obviously, to develop a reflex in this species, it is necessary to change the experimental design; perhaps catfish simply do not distinguish colors. It can also be assumed that this type of fish obtains food at the bottom and therefore does not strive for the surface of the water.

For a detailed analysis of the physiological mechanisms of fish behavior, there is often a need to study this behavior under experimental conditions, where an accurate dosage of factors that influence the fish and a fine recording of the body’s reactions are possible.

In an experiment, it is difficult to say that differences in fish learning are due to their phylogeny. Quicker environmental features species have a greater influence on animal learning. But firmer statements can be made after deeper and longer research.

Municipal institution "Kamenskoye Administration" public education»

Regional research competition

and projects junior schoolchildren"Debut in Science"

Municipal educational institution "Kamenskaya secondary school No. 3"

Class 5

Direction: the world around us

RESEARCH

Development of conditioned reflexes in aquarium fish guppy

Head: Yatskova Elena Aleksandrovna

biology teacher first qualification category

Student: Shapovalova Alina Nikolaevna

Kamenka 2013

Content

Introduction…………………………………………………………………………………..3

Chapter 1. Theoretical part

Chapter 2. Practical part

2.1. Development of a conditioned reflex in aquarium fish

to red and blue………………………………………………………..10

Conclusion…………………………………………………………………………………..12

References……………………………………………………………13

Applications

Introduction

An aquarium is, at first glance, a small vessel with water for keeping aquatic animals and plants. (Appendix 1, Fig. 3) But in practice, this is a whole source of knowledge for young researchers. A little over a year ago, 8 guppies appeared in my aquarium, which were given to me. Today their number is more than 100 individuals. A student's usual routine includes waking up every morning with an alarm clock, turning on the lights, and a whole series of preparations. As a rule, I started feeding the fish immediately after turning on the light. Over time, I noticed that the fish began to wake up with me and, after the alarm clock rang and the lamp turned on, they actively fussed around the glass in anticipation of a delicious breakfast. I was interested in the question: how to explain such ingenuity of creatures with a small brain, because before me their feeding schedule was significantly different? Does a change in owner and feeding conditions harm aquarium fish? It turned out that this behavior is explained by conditioned reflexes. So I set myselftarget :

develop conditioned reflexes to red and blue colors in aquarium guppy fish. For this purpose I have determined the followingtasks :

study the history of the discovery of reflexes in animals and

find out what reflexes are in aquarium fish

Object research are aquarium fish guppy.Subject Research into the conditioned reflexes of aquarium guppy fish. Testing of the research results is carried out on domestic aquarium fish, guppies, in the amount of 110 individuals. The practical value of the work lies in the application of the research results in the school’s wildlife corner, as additional material in biology lessons, meetings of the school environmental team and other extracurricular activities.

The work consists of an introduction, a chapter of a theoretical part with 3 paragraphs, a chapter of a practical part, a conclusion, a list of references, and applications.

Chapter 1. Theoretical part

Reflex (from Latin reflexus - turned back, reflected) is a reaction of the body carried out by the nervous system in response to the influence of external or internal stimuli. The idea of reflexes was first put forward by R. Descartes, who classified them as automatic involuntary actions. I.M. Sechenov proved that “all acts of conscious and unconscious life, according to the method of origin, are reflexes» This concept was developed by I.P. Pavlov, who created the doctrine of unconditioned and conditioned reflexes.

Pavlov Ivan Petrovich (1849 - 1936) - academician, professor of physiology, famous Russian scientist, creator of the doctrine of “conditioned reflexes”. His main work - “Twenty years of experience in the objective study of higher nervous activity (behavior) of animals” (a collection of articles, speeches, reports) - was published in 1923. I. P. Pavlov and his students for the first time gave precise experimental confirmation of Sechenov’s theoretical views, father of Russian physiology. The subject of Pavlov's direct observations was the work of the salivary glands in dogs. It is known that, due to an innate reflex mechanism, a dog secretes saliva when food enters its mouth; this is a natural or “unconditioned” reflex. Pavlov's experiments revealed that if every time a dog is fed, an electric light bulb is lit (or a bell is given), then a certain connection will be established between the nervous mechanism of the visual apparatus and the reflex mechanism of salivation. As a result of repeating similar experiments, just one type of light bulb by itself, without eating, will cause salivation. A new connection is formed, a new path in the nervous system, a “habit”; this is what Pavlov calls an “artificial” or “conditioned” reflex. Unconditioned reflexes are innate, constant (instincts), conditioned reflexes are fickle, temporary, acquired (experience, habit). The biological significance of the conditioned reflex connection is enormous: by individualizing the body's responses to external stimuli, it endlessly refines its orientation in the surrounding world. Studying the results of his simple experiments on dogs, Pavlov came to the idea that all mental activity is nothing more than a set of reflexes, i.e. natural responses to external stimuli.

The emergence of reflexes is associated with the appearance of individual nerve cells interacting with each other through synaptic contacts. Further specialization of reflexes occurs with the emergence and complexity of the central nervous system (CNS). The biological significance of reflexes is to maintain the functional integrity of a living organism and the constancy of its internal environment (homeostasis), as well as to ensure effective interaction organism with the external environment (adaptive behavior).

Conclusion . All animals have two types of reflexes: innate (unconditioned) and acquired (conditioned)

In response to various environmental stimuli perceived by the senses, fish respond with a rather limited number of motor reactions: they swim up or swim away, dive, grab food with their mouths, avoid obstacles that interfere with swimming, etc. The light stimulus, depending on its brightness and high-quality composition acts differently on the receptors of the fish’s eyes and causes a corresponding nerve impulse, which is transmitted along the sensory nerves to the brain, and from here reflexively rushes along the motor nerves to the skin. Pigment cells (chromatophores) located in the skin of fish undergo changes under the influence of nerve impulses due to the expansion or contraction of pigment grains or their movements in the chromatophores. This is what causes a reflex change in body color. In natural bodies of water with a varied color of the soil, fish instinctively stay in places suitable for themselves, but if they are forced to move to a different environment (for example, into a body of water with a uniform bottom color that does not match their color), they can adapt to new conditions through the reflex described above changes in skin color. In both cases, the survival of the species is ensured by a subtle, as I. P. Pavlov put it, “balancing the organism with the environment,” achieved by the activity of the nervous system. The color of the soil in natural conditions served as a signal of safety to the fish, since only when they fell into its background, they became less noticeable to enemies, and they were less likely to be pursued by predators.

Fish are able to distinguish not only color, but also shape, as well as the size of moving objects. For example, by looking at the tweezers from which fish take food, a conditioned food reflex is developed over time. At first, the fish are frightened by the tweezers submerged in water, but, receiving food from it each time, after a while they begin to trustingly swim up to the tweezers, instead of swimming away. This means that the fish have developed a conditioned reflex to tweezers as a stimulus that coincides with the unconditioned stimulus—food. IN in this case tweezers serve as a food signal. When regularly feeding fish from a box, they begin to react not only to the approach of a feeding person to the aquarium, but also to the sight of the box. If you pass the box to a person standing on the other side of the aquarium, the fish will go there. This means that they have developed a conditioned reflex to the figure of a person with a box as a generalized image that generally plays the role of a food signal.

Conditioned reflexes to sound stimuli . Aquarium lovers know well how to train fish to gather at the surface of the water when signaled by tapping on the wall. Researchers who deny hearing in fish claim that fish swam only when they saw a person coming to the pond or when his steps caused the soil to shake. However, this does not exclude the participation of sound as one of the parts of a complex stimulus. The issue of fish hearing has long remained controversial, especially since fish have neither a cochlea nor the main membrane of the organ of Corti. It was resolved positively only by the objective method of conditioned reflexes (Yu. Frolov, 1925). The experiments were carried out on freshwater (crucian carp, ruffe) and marine (cod, goby) fish. In a small aquarium, the test fish swam on a string attached to an air transmission capsule. The same thread was used to supply electric current to the fish’s body; the second pole was a metal plate lying on the bottom. The sound source was a telephone handset. After 30 - 40 electric shocks, an auditory conditioned protective reflex was formed. When the phone was turned on, the fish dived without expecting an electric shock. They also discovered that the development of one conditioned reflex facilitated the formation of subsequent ones.

Conditioned reflexes to light stimuli . Various conditioned reflexes based on food reinforcement were developed during training of fish in order to study their vision. If you feed macropods with red chironomid larvae, then the fish will quickly attack the wall of the aquarium when lumps of red wool, similar in size to the larvae, are glued to the glass outside. The micropods did not react to green and white lumps of the same size. If you feed the fish with pellets of white bread crumb, they begin to grab the white wool balls that come into view. The high development of visual perception of carp is evidenced by its ability to distinguish the color of an object even in different conditions lighting. This property of constancy of perception was also manifested in carp in relation to the shape of an object, the reaction to which remained definite, despite its spatial transformations.

Complex food acquisition reflexes . To better compare the indicators of conditioned reflex activity of different animal species, natural food-procuring movements are used. Such a movement for fish is to grab a bead suspended on a thread. The first random grasps are reinforced with food and combined with an auditory or visual signal, to which a conditioned reflex is formed. Such a conditioned visual reflex, for example, was formed and strengthened in crucian carp over 30-40 combinations. Color differentiation and a conditioned brake were also developed. However, repeated modifications of the signal meaning of positive and negative stimuli turned out to be an extremely difficult task for fish and even led to disorders of conditioned reflex activity.

Conclusion . Aquarium fish can develop various conditioned reflexes: to light, to the color and shape of objects, to time, etc.

1.3. General characteristics of aquarium fish guppies

Domain: Eukaryotes

Kingdom: Animals

Type: Chordata

Class: Ray-finned fish

Order: Cyprinodontiformes

Family: Poeciliaceae

Genus: Pecilia

Species: Guppy

International scientific name

Poecilia reticulata (Peters, 1859)

Guppy (lat. Poecilia reticulata) is a freshwater viviparous fish. Guppies have pronounced sexual dimorphism - males (Appendix 1, Fig. 1) and females (Appendix 1, Fig. 2) differ in size, shape, and color. The size of males is 1.5-4 cm, slender, purebred individuals often with long fins. The color is often bright. The size of females is 2.8-7 cm, with an enlarged abdomen, in the anal area of which eggs are visible. The fins are always proportionally smaller than those of males. Females from natural habitats and many breeds are gray with a pronounced rhombic mesh of scales, for which the species received its name: reticulum from lat. - mesh, mesh.

The most popular and unpretentious aquarium fish. IN home aquarium inhabits all layers. In captivity, it lives longer and grows larger than in nature. Aquariums most often contain different breeds of guppies or the result of their mixing.

Guppies got their name in honor of the English priest and scientist Robert John Lemcher Guppy, who in 1886 made a report to members of the Royal Society in which he spoke about fish that do not spawn, but give birth to live young.

The optimal water temperature is +24 °C. They survive in the range from +14° to +33°C. The area of the aquarium for one pair of guppies is 25x25 cm with a water level of about 15 cm. They are omnivores - they need small food of both animal and plant origin. These are mainly protozoa, rotifers (phylodina, asplancha); crustaceans (cyclops, daphnia, moina, mosquito larvae - coretra, bloodworms); mosquito pupa; lower plants(chlorella, spirulina), as well as some algal fouling. For adult fish it is necessary to arrange one or two fasting days per week (when the fish are not fed).

Conclusions for Chapter 1.

I.P. Pavlov made a significant contribution to the study of reflexes

To develop a conditioned reflex, a long-term combined action of unconditioned and conditioned stimuli is necessary.

Fish can develop simple conditioned reflexes to light, sound, a moving object, time, size and color of objects, etc.

Guppies are unpretentious viviparous aquarium fish, convenient for research.

Chapter 2. Practical part

2.1. Development of a conditioned reflex in aquarium fish to red and blue colors

To successfully conduct an experiment on the development of a conditioned reflex, the following requirements must be met:

1. Feed the fish in different time, otherwise a conditioned reflex is developed for a while.

2. The conditioned stimulus should act first - in this case it is a red or blue object

3. The conditioned stimulus is ahead in time or coincides with the unconditioned stimulus - food (food)

4. The conditioned stimulus and feeding are combined several times

5. A conditioned reflex is considered developed if the fish swim to the walls of the aquarium when a conditioned stimulus appears (Appendix 2, Fig. 4, 5.)

The experiment is carried out with aquarium fish, guppies. At the time of the experiment, there were 110 individuals. Before the experiment, they were kept in the same aquarium, i.e. under the same conditions: feeding time, temperature and light conditions, composition and amount of water. All individuals developed the same conditioned reflex: in the morning (at 6.30 o’clock) after the alarm signal on the mobile phone and the light was turned on, feeding began. All individuals simultaneously swam to the edge of the aquarium in anticipation of food. During the day, the lights were turned on as needed, but not every time it ended with feeding the fish.

To conduct an experiment, i.e. To develop a conditioned reflex to red and blue colors (feeding after the appearance of a box with a red lid or a blue balloon), the fish were divided into 3 parts (placed in 3 aquariums). The control group (30 individuals) was kept under the same conditions (the terms and conditions of feeding did not change). The first experimental group (40 animals) did not receive food in the morning after the previous signals. Feeding began after a box with a red lid appeared at the walls of the aquarium and most of the fish would pay attention to it. During breaks between feedings, a blue balloon was held against the walls of the aquarium; the fish swam to it, but feeding did not occur.

The second experimental group (40 individuals) did the opposite: after the appearance of a blue balloon, the fish received food. In the intervals between feedings, a red box appeared at the walls of the aquarium for several minutes; the fish swam to it, but did not receive food.

Over time, the first and second experimental groups of individuals developed a conditioned reflex to feed after the appearance of a red or blue object, respectively. The results of the experiment are shown in Table 1.

Table 1. Observation diary

date

Time of presentation of the conditioned stimulus and feeding

Approximate time for fish to approach the walls of the aquarium

1 group

2nd group

1 group

2nd group

02.01

07.00

07.30

6.5 minutes

09.01

14.45

14.25

5 minutes

5.5 minutes

16.01

16.30

16.00

4.5 minutes

4 minutes

23.01

07.00

07.20

3.5 minutes

3 minutes

30.01

15.00

15.50

2 minutes

2.5 minutes

06.02

17.00

17.30

1 minute

1.5 minutes

13.02

15.00

15.10

30 seconds

50 seconds

20.02

07.10

07.20

10 Seconds

20 seconds

27.02

14.30

14.50

10 Seconds

RESULT

a reflex has been developed to a certain color

Conclusions for Chapter 2.

To develop a conditioned reflex in aquarium fish, guppies, certain conditions must be met.

During the experiment, a conditioned reflex was developed in aquarium fish guppies to red and blue colors

Conditioned reflexes contribute to the adaptation of organisms to environmental conditions (in this case, feeding conditions)

Conclusion

Aquarium - small world ok, which provides a unique opportunity to bring a piece of nature into your home, where everything is coordinated, lives in harmony, develops, changes, revealing itself to the observer. This fragile world depends entirely on the owner, because... without his constant care and attention he will die.

In highly organized animals with a central nervous system, there are two groups of reflexes: unconditioned (innate) and conditioned (acquired). Reflexes have an important adaptive significance for maintaining the integrity of the body, full functioning and constancy of the internal environment. In aquarium fish, it is possible to develop all sorts of conditioned reflexes to various stimuli: time, light, color and shape of objects, etc. During the experiment, conditioned reflexes were formed in aquarium guppy fish to red and blue colors based on the unconditioned (food) color.

In this work, we consider an example of the development of only one conditioned reflex. The acquired knowledge gives rise to a wide range of opportunities for scientific knowledge laws of nature and improving one’s own knowledge.

Bibliography

Biological encyclopedic Dictionary. Ch. ed. M. S. Gilyarov. 2nd ed., corrected - M.: Sov. Encyclopedia, 1986. – 381 p.

Kogan A.B. Fundamentals of the physiology of higher nervous activity. 2nd ed. , processed and additional - M.: Higher School, 1988. - 368 p.

Mikhailov V.A. All about guppies and other viviparous animals. Popular fish. 2nd edition, revised and expanded. - M.: Svetoch L, 1999. - 96 p.

Muddy Hargrove, Mick Hargrove. Aquariums for dummies. - 2nd ed. - M.: “Dialectics”, 2007. - P. 256.

Joint Scientific Council "Human and Animal Physiology" (USSR Academy of Sciences). /ed. Chernigovsky V.N. – M.: Nauka, 1970.

Reshetnikov Yu. S., Kotlyar A. N., Rass T. S., Shatunovsky M. I. Five-language dictionary of animal names. Fish. Latin, Russian, English, German, French. /under general edition acad. V. E. Sokolova. - M.: Rus. lang., 1989. - P. 183.

Frolov Yu.P. I.P. Pavlov and his doctrine of conditioned reflexes. State ed. biological and medical literature, 1936 – 239p.

http://books.google.ru

ANNEX 1

Rice. 1 Male guppy

Rice. 2 Female guppy

Rice. 3 Aquarium fish guppies

APPENDIX 2

Rice. 4 Development of a conditioned reflex to the color red

Fig. 5 Development of a conditioned reflex to the color blue

Conditioned reflexes of fish. The continuous neural tube of vertebrates creates the most favorable conditions for communication of all parts of the nervous system. Its leading department, the brain, concentrates the functions of controlling behavior, and it receives extraordinary development structures that carry out conditioned reflexes.

Anyone who keeps fish in an aquarium knows how easy it is to teach them to swim to the surface when the owner makes movements with his fingers, which are usually used to pour a pinch of food into the water. The sight of a person's hand approaching the surface of the water, which previously caused a defensive reaction of flight, now becomes a signal of a conditioned food reflex. Aquarium fish can develop a variety of conditioned food reflexes, for example, to lighting a certain place in the aquarium, accompanied by feeding in this place, to tapping on the wall of the aquarium, if accompanied by feeding, etc.

In the natural environment, the ability to develop new behavioral skills helps fish adapt to changing living conditions.

The new conditioned reflexes that are formed turn out to be stronger than many innate instincts and can change them and even completely suppress them. For example, if a predatory pike is placed in the same aquarium with its usual prey - crucian carp, separated by a glass partition, then the pike begins to rush at the crucian carp. However, after repeated painful blows of its snout against the glass, it stops trying to grab its prey. If you now remove the partition, the pike and crucian carp will calmly “swim” next to each other.

The fact is that fry, bred in artificial conditions at a fish hatchery, when they get into an open reservoir, river or lake, die en masse from predators, since safe life in industrial pools did not give them a reason to develop protective behavior. Increasing the survival rate of fry of valuable species of commercial fish can be achieved by artificially developing in them conditioned defensive reflexes to the sight of predatory fish.

To develop such reflexes, a stuffed animal, reproducing the figure of a predator fish, was lowered into a pool with fry, and an electric current was passed through the water or beaten on its surface. After a number of such combinations, only the appearance of the figure of a predator caused the fry to flee. ABOUT practical significance This method of increasing the productivity of fish farming can be judged from the results of an experiment conducted in one of the pond farms in Karelia. A pre-calculated number of fry of a valuable fish and one predator, a chub, were released into a fenced area of the pond. After 1-2 days, we counted how many fry survived.

It is known that amateur fishermen, in order to ensure good catches in their favorite gestures, especially in quiet backwaters, systematically bring and throw into the water scraps and everything that can be edible for fish. It is possible that in this way the fish develop conditioned food reflexes that attract them to the feeding site. Behind Lately There has been information that some coastal fisheries are feeding fish in certain places in order to increase their catch.

Conditioned reflexes of birds. The everyday observation that “a crow is afraid of a bush” indicates a good ability to develop conditioned reflexes. Birds have this ability already at an early age. For example, chickens quickly imitate a pecking hen, and rhythmic tapping becomes a signal for them to peck at the food. This way you can encourage feeding activity in weak chickens.

Cases are described in which chickens, hunting for flies, grabbed a wasp or a bee and, once stung, made no more mistakes. Other observations have shown that chickens quickly learn to distinguish edible from inedible caterpillars by shape and color. If chickens are fed only by hand, then they stop responding to the clucking of the chicken and run after their breadwinner squeaking.

Week-old chicks can develop a variety of food and defensive conditioned reflexes to light, sound and other signals. However, fine discrimination of these signals is achieved only at the age of 2-3 weeks. Adult chickens quickly adapt to the daily routine in the chicken coop and gather at the feeders exactly at the feeding hours.

Since the main signal for chicken activity is light.

Even more theoretically and practically interesting results were obtained in experiments with the transformation of one natural day in two artificial. To do this, lighting and darkening were alternated in the poultry house during each day in the following order: 0-4 hours - normal night, from 4 to 12 hours - light day, from 12 to 16 hours - darkening, creating a “second night”, after which 16 to 24 hours deep into the night, artificial lighting maintained the atmosphere of a bright “second day.” The chickens raised under these conditions learned the new regime and in two “days of light” during the day they managed to eat more food, gain more live weight, and many of them began to lay eggs twice a day. As a result, the productivity of chickens has increased markedly.

Young birds learn to find their way to their nest, primarily by visual cues. They circle over it for a long time, memorizing character traits surrounding landscape. The ability of pigeons to return home even from afar has been used since ancient times in the form of pigeon mail. Pigeon mail has not lost its importance to this day, especially in military affairs: it lacks the main disadvantage of radio communications, in which messages are easily intercepted, and the location of the transmitter is accurately determined by direction finding. About a million carrier pigeons took part in the First World War. In the Second World War, only English air Force had several tens of thousands of carrier pigeons in service.

Conditioned reflexes of rodents. House mouse learns, with the help of complex tricks, to obtain food for itself and to escape from the dangers that await it at every step as a result of persecution by humans, cats, etc. The life of mice and rats in winding paths the underground developed their ability to quickly navigate them and remember all the entrances and exits. Therefore, various experiments on the psychology of learning are carried out on laboratory white rats, measuring the time required to find a way out of confusing roads and a labyrinth.

To study the properties of higher nervous activity in mice, rats, and rabbits, they develop conditioned reflexes to light, sound, olfactory and other signals in special chambers. If a food reflex is developed, then the feeder opens upon a signal, and if a defensive reflex is developed, then an electric current is connected to the metal floor grate. In this way, the properties of conditioned reflexes and their changes under various influences on the animal’s body (physical work, medications, hunger, etc.) are studied.

The peculiarities of the lifestyle of mice and rats in the dark corners of the underground are reflected in the fact that they form conditioned reflexes to sound signals much more easily than to visual signals. However, they also develop visual conditioned reflexes well. This can be used to show the effective experience of "putting mice on a train." If some white tame rats or mice are marked with red paint and fed only in red carriages, and the rest - in white ones, then when the train arrives they will scatter to “their” carriages,

The behavior of beavers, known for their valuable fur, reaches high perfection. With amazing skill they build dams that raise the water level in the river. (It is known that beavers’ homes have an underwater entrance.) At the same time, old beavers teach young beavers the most effective techniques for gnawing and felling trees, cutting them up, floating them to the construction site and laying them in the body of the dam. All these works are carried out jointly by all members of the colony under the leadership of the leaders. The "language" of beavers is interesting. They call each other out of their homes by whistling, exchange guttural sounds when felling trees, etc. Depending on local conditions, the size of the river, the condition of the banks and other circumstances, beavers choose different methods and means of construction, erecting complex hydraulic structures. Conditioned reflexes of ungulates. In pigs from the very early age a variety of conditioned reflexes can be developed. This is used, for example, to collect piglets after a walk. It is enough for the pig farm to give a certain signal for several days before each feeding (hitting the bottom of the bucket like a drum), and at this signal the piglets will run together to the feeders from all over the pen.

Sheep and goats develop complex food conditioned reflexes that have been studied both in the laboratory and in natural conditions. The secretion of saliva in sheep that were transferred from confinement to grazing was studied.

In the first two days, neither the path to the pasture, nor even the proximity to grazing sheep caused salivation in the experimental sheep. On the third day, her mouth watered at the sight of grazing sheep. Then conditioned reflexes were formed to the sight of the pasture, the road to it, and after two months it was enough to take the sheep out of the stall into the corridor, and it would already begin to salivate.

Based on signals from the natural environment, sheep develop adaptive conditioned reflexes that cause changes in metabolism in the body. The sight of wind-bending grass increases heat production, while bright sunlight reduces heat production. This regulation of metabolism allows the sheep to tolerate and winter snowstorms, And summer heat in an open field.

Of great importance for increasing the milk yield of cows are the conditioned reflexes of milk production and milk yield, which are developed in them by the conditions of housing and milking. A certain daily routine, constant milking time, the same milkmaid become signals that reflexively stimulate the mammary glands in advance. Everything that interferes with the manifestation of this reflex - noise and disorder, rough handling of the cow, untimely milking, frequent changes of milkmaids - leads to a decrease in milk yield even in highly productive cows. The practice of advanced dairy farms has shown that the use of conditioned reflex factors can be an effective means of increasing milk production.

As a result of centuries-old experience of domestication and economic use, a person uses a whole complex of signals to control its behavior. Well-known verbal commands are reinforced by musculocutaneous irritations through the reins and whip for a draft horse, reins, leg (the inner part of the rider's shin facing the horse) and spurs for a riding horse. In circus training, music is often used as signals for the horse's movements, to the rhythm of which the horse "dances".

The horse has a keen sense of hearing and smell, and is well versed in the terrain. Therefore, if you get lost, for example, in a snowstorm, you can let her find her way by the smell of a home brought from afar or the sounds of barking dogs that are inaudible to us.

In our country, serious work is underway to tame the inhabitant of the northern forests - mighty moose, which is able to overcome swamps and off-road conditions that are beyond the strength of a horse. However, the most interesting prospects are opening up in the use of moose as dairy animals.

Last name, first name of the author of the article Bogdanova Diana Class 5d

OS name Municipal budgetary educational institution Lyceum No. 5 of the city of Yelets, Lipetsk region

Last name, first name, patronymic of the manager Zamury Svetlana Yurievna

Work theme:

e-mail: [email protected]

Development of conditioned reflexes in aquarium fish
Nowadays, the vast majority of people, no matter where they live or what they do, have to deal with animals. Inhabitant modern city, one way or another, comes into contact with animals, be it fighting cockroaches in the kitchen or communicating and caring for pets.

Last year, for my birthday, my parents gave me an aquarium. I was very happy about this.

Many people say that keeping fish is not fun because they cannot be trained. But training is based on the development of a conditioned reflex. And my observations of fish confirmed that they can develop conditioned reflexes.

Problem: How are conditioned and unconditioned reflexes related?

Hypothesis: Aquarium fish can develop a conditioned reflex to any stimulus.

The purpose of my research: To prove that the conditioned reflex in fish is developed on the basis of the unconditioned, having a leading influence of the conditioned stimulus

Research objectives:

1. Study the literature on the topic: “Animal behavior. Conditioned and unconditioned reflexes";

2. Identify and describe the fish that live in my aquarium.

3. Conduct experiments on the development of conditioned reflexes in animals.

4. Find out to which stimulus the conditioned reflex is developed faster.

Object of study: aquarium fish

Subject of research: conditioned reflexes in animals

In my work I used the following research methods:

Studying scientific literature on the topic “Conditioned and unconditioned reflexes”; Description of aquarium fish; An experiment on the development of conditioned reflexes to various stimuli.

Unconditioned and conditioned reflexes.

Unconditioned reflexes- hereditarily transmitted (congenital) reactions of the body, inherent in the entire species.

Conditioned reflex- This is the body’s reaction to a stimulus developed during development.

Unconditioned reflexes are the main innate foundation in the behavior of an animal, which ensures (in the first days after birth, with the constant care of parents) the possibility of the normal existence of the animal. However, as the animal develops, it acquires more and more large quantity individually acquired acts of behavior. These are conditioned reflexes.

Conditions for the formation of conditioned reflexes.

The first condition for the formation of a conditioned reflex is the coincidence in time of the action of a previously indifferent stimulus with the action of some unconditioned stimulus that causes a certain unconditioned reflex.

The second condition for the formation of a conditioned reflex is that the stimulus that turns into a conditioned reflex must somewhat precede the action of the unconditioned stimulus.

When training an animal, commands and gestures should be given somewhat earlier than the unconditioned reflex stimulus begins to act. For example, when training a dog to walk side by side, the verbal command “nearby” should slightly (by 1-2 seconds) precede the jerk of the leash, which causes an unconditional reflex reaction. If the stimulus, which should become a conditioned reflex signal, is given after the unconditioned reflex stimulus, then the conditioned reflex will not be developed.

Therefore, when training animals, it is necessary to strictly ensure that conditioned signals slightly precede the action of the unconditioned stimulus.

The third extremely important condition for the formation of a conditioned reflex is that the hemispheres of the animal’s brain must be free from other types of activity during the development of the conditioned reflex.

When developing conditioned reflexes, one must try to exclude, as far as possible, the influence of various extraneous stimuli. Fourth condition the formation of conditioned reflexes is the strength of the conditioned stimulus. Conditioned reflexes to weak conditioned stimuli are developed slowly and are of smaller magnitude than to strong stimuli. However, it must be borne in mind that excessively strong conditioned reflex stimulation can cause in some dogs (especially those with a weak type of nervous activity) not an improvement, but, on the contrary, a deterioration in their conditioned reflex activity. And in some cases, the conditioned reflex may not be developed at all.

It is also necessary to keep in mind that the strength of the unconditioned stimulus during the development of a conditioned reflex must be greater than the strength of the conditioned stimulus, since the conditioned stimulus is of great strength (for example, strong sound, shout, etc.) can slow down the manifestation of an unconditioned reflex in an animal (for example, a food one).

The fifth condition for the formation of conditioned reflexes is the state of the unconditioned reflex on the basis of which the conditioned reflex is developed. During the development of a conditioned reflex, the unconditioned reflex must be in a sufficiently excitable state. If a conditioned reflex is developed on food unconditioned reflex, it is necessary that the animal gets hungry; a fed dog will respond weakly to food reinforcement, and the conditioned reflex will be developed slowly.

2. Definition and description of the inhabitants of my aquarium

Parrot(Pelvicachromis pulcher) lives in rivers with brackish water in West Africa . This fish was first brought to Europe in 1951. The parrot has an elongated, laterally compressed body. The profile of the back is curved more than the belly. The front of the head, with a terminal mouth and sloping forehead, is slightly curved downwards and resembles the head of a parrot (hence the name). More often, a wide dark brown stripe runs along the entire body, from the snout to the end of the caudal peduncle. The back is dark. There is a cherry-colored spot on the abdomen, the bottom of the head is golden.

Sumatran barbs(Barbus tetrazona) - peaceful, schooling, very active fish.The body of these barbs is high, strongly compressed laterally. No mustache. The general color is golden-pink, the back is darker with a red tint, and the belly is yellowish-white. There are four vertical black stripes on the sides. The first goes through the eye, the second behind the pectoral fin, the third behind the dorsal fin and the last at the beginning of the caudal fin.

Shark barb(Balantiocheilus melanopterus ) lives in rivers and streams with fast currents in Thailand and the islands South-East Asia: Kalimantan and Sumatra. Appearance The shark ball is discreet, somewhat reminiscent of a roach. It has a narrow, laterally compressed body, large eyes and a lower mouth. There are no mustaches. The main body color is silver-steel. The scales are large, resembling a small mirror (creating a sparkling effect). The pectoral fins are colorless. The rest are either transparent or yellowish with a wide black border. Sexual differences: males are slimmer and smaller than females. In young individuals it is almost impossible to distinguish the sex. They reach a length of up to 35 cm. They grow very quickly. Pearl gourami(Trichogaster leeri) . The main background is cream, and the entire body and translucent fins are covered with numerous iridescent light spots, reminiscent of pearls (hence the name). The abdomen of males is blood-red in color, their dorsal fin is pointedly elongated, the anal fin is powerful, with fringed elongated rays. A black stripe runs along the body, starting from the snout and ending at the base of the caudal fin. The fish reaches a length of 11 cm.

Ancistrus dolichopterus) Family Chain catfish (Loricariidae). Ancistrus vulgaris lives in mountain rivers South America in the tributaries of the Amazon, in the Andes in Peru, as well as in the upper reaches of the Orinoco in Venezuela. The body shape of Ancistrus vulgaris is teardrop-shaped and flattened, the head is wide. The body is covered with rows of wide bony plates. The main color ranges from light gray yellowish to dark gray and black with light specks. The color is very variable and often ancistrus “turn pale”. Adult male ancistrus can reach up to 10 cm. The mouth of the fish is in the form of a suction cup with elongated lips, equipped with horn-like scrapers that allow you to remove fouling from the walls of the aquarium, snags, and plant leaves.

Danio rerio (Brachydanio rerio) - fish of the upper layers of the coastal part of standing and slow-flowing reservoirs of Southeast Asia, usually floating between stems aquatic plants and coastal grasses hanging into the water. Here she looks for her prey - small invertebrates. Here the fish spawn, scattering eggs in dense thickets coastal plants. Danio is one of the most common aquarium fish. The fish are very active and unpretentious. They live even in the smallest aquariums. Danio rerio stays mainly in the middle and upper layers water. When frightened, they can jump out of the water, so the aquarium must be covered with a tight lid. It is preferable to keep zebrafish in a group of 8-10 fish. Observing the fast and graceful movements of zebrafish gives aquarium enthusiasts great pleasure

3.Development of conditioned reflexes to various stimuli in fish.

Method of doing the work

Develop a conditioned reflex in fish to three different stimuli: light; bead; tapping on the aquarium.

Experimental conditions: feed the fish at different times, otherwise a conditioned reflex will be developed for time.

Rules for developing conditioned reflexes:

a) the first to act is an indifferent stimulus - light; b) it is ahead in time or coincides with the unconditioned stimulus - food (food); c) light and feeding are combined several times; d) when the light is turned on, the fish swim to the walls of the aquarium, which means that the indifferent stimulus (bead) begins to cause the same reaction as the unconditioned stimulus (food); e) a conditioned reflex has been developed.

In the same way, I developed a conditioned reflex to other stimuli (a bead, a knock)

Table No. 1 Development of a conditioned reflex to light

Date of observation	Light and feeding time
02.09.2012	08.30	5 minutes
03.09.2012	10.10	4 minutes
04.09.2012	18.30	3 minutes
10.10.2012	21.00	1 minute
12.10.2012	07.20	30 seconds
18.10.2012	19.00	10 Seconds	18.10.2012

Conclusion: The conditioned reflex is developed on the basis of the unconditioned, having a leading influence of the conditioned stimulus - light. In the brain, a temporary connection is established between the visual and food zones of the cerebral cortex. Light became the dominant stimulus. The conditioned reflex was developed after 46 days.

Table No. 2 Development of a conditioned reflex to a bead

Date of observation	Bead and feeding time	Time for fish to approach food	Date of development of the conditioned reflex
28.10.2012	08.30	5 minutes
29.10.2012	10.10	4 minutes
30.10.2012	18.30	3 minutes
05.11.2012	21.00	2 minutes
08.11. 2012	07.20	1 minute
10.11.2012	19.30	30 seconds
18.11.2012	20.00	5 second	18.11.2012

Conclusion: The conditioned reflex is developed on the basis of the unconditioned one, having a leading influence of the conditioned stimulus - the bead. In the brain, a temporary connection is established between the visual and food zones of the cerebral cortex. The bead became the dominant stimulus. The conditioned reflex is developed after 20 days.

Table No. 2 Development of a conditioned reflex to tapping on the aquarium

Date of observation	Knocking and feeding time	Time for fish to approach food	Date of development of the conditioned reflex
28.11.2012	08.30	5 minutes
29.11.2012	10.10	4 minutes
30.10.2012	18.30	3 minutes
05.12.2012	21.00	1 minutes
08.12. 2012	07.20	30 seconds
10.12.2012	19.30	20 seconds
13.12.2012	20.00	5 second	13.11.2012

Conclusion: The conditioned reflex is developed on the basis of the unconditioned, having a leading influence of the conditioned stimulus - knocking. In the brain, a temporary connection is established between the auditory and food zones of the cerebral cortex. The knocking became the dominant irritant. The conditioned reflex is developed after 15 days.

Conclusion

After conducting research, I came to the conclusion: conditioned reflexes in fish are developed on the basis of the unconditional, having a leading influence of the conditioned stimulus. Aquarium fish can develop a reflex to any stimulus.

Tapping on the wall of the aquarium became a stronger stimulus, and therefore the conditioned reflex developed faster.

During the study, my hypothesis was confirmed.

Watching fish and writing research work taught me to independently work with sources of information (books, the Internet), process information, and keep an observation diary.

During the work, I realized that the aquarium is unique opportunity bring a piece of nature into your home, create your own little world, where everything is coordinated, everything lives in harmony, develops, changes, revealing itself to the observer. This fragile world depends entirely on its owner - without constant care and attention it will die.

We must learn to live, giving the opportunity to live to other organisms on our planet. Studying animal behavior will help us understand ourselves.

Bibliography

1. Bertron R. Feelings of animals. - M., 1972

2. Sergeev B. From amoeba to gorilla. - L.: Children's literature, 1988.

3. Noga G.S. Observations and experiments in zoology. - M.: Education, 1979

4. Sergeev B. F. Entertaining physiology. - M.: Bustard, 2004.

5. I explore the world: Children's encyclopedia: Animals [text, drawing]. – M.: LLC “AST Publishing House”, 2001 – pp. 221 – 223.

Remote Access Resources

6.Ziper, A.F. Control of the behavior of animals and birds. Reflexes in the life of animals [text]. - Access mode.

III. Examples of motor reflexes.

1. Muscle reflexes of stretching and braking.

Consider the muscle stretch reflex. It is designed to regulate the position of the limbs, ensure a stationary position of the body, and support the body while it is standing, lying or sitting. This reflex maintains the constancy of muscle length. Stretching a muscle causes activation of muscle spindles and contraction, i.e. shortening of the muscle that counteracts its stretching. For example, when a person sits, the abdominal muscles are stretched and their tone increases, counteracting the flexion of the back. Conversely, too much muscle contraction weakens the stimulation of its stretch receptors, muscle tone weakens

Let us consider the passage of a nerve impulse along a reflex arc. It should immediately be noted that the muscle stretch reflex is one of the simplest reflexes. It passes directly from the sensory neuron to the motor neuron (Fig. 1). The signal (irritation) comes from the muscle to the receptor. The impulse travels along the dendrites of the sensory neuron to the spinal cord and there through the shortest route into the motor neuron of the somatic nervous system, and then along the axon of the motor neuron the impulse reaches the effector (muscle). Thus, the muscle stretch reflex is carried out.

Fig.1. 1 – muscle; 2 – muscle receptors; 3 – sensory neuron; 4 – motor neuron; 5 – effector.

Another example of a motor reflex is the inhibition reflex. It occurs as a response to the action of the stretch reflex. The inhibitory reflex arc includes two central synapses: excitatory and inhibitory. We can say that in this case we are observing the work of antagonist muscles in a pair, for example, a flexor and an extensor in a joint. The motor neurons of one muscle are inhibited while the other component of the pair is activated. Consider knee flexion. At the same time, we observe stretching of the extensor muscle spindles, which increases the excitation of motor neurons and the inhibition of flexor motor neurons. In addition, a decrease in the stretch of flexor muscle spindles weakens the excitation of homonymous motoneurons and the reciprocal inhibition of extensor motoneurons (disinhibition). By homonymous motor neurons we mean all those neurons that send axons to the same muscle or excite the muscle from which the corresponding path from the periphery to the nerve center originates. And reciprocal inhibition is a process in the nervous system, based on the fact that the same afferent pathway excites some groups of cells and inhibits other groups of cells through intercalary neurons. Ultimately, extensor motor neurons fire and flexor motor neurons contract. Thus, the length of the muscle is regulated.

Let us consider the passage of a nerve impulse along a reflex arc. The nerve impulse originates in the extensor muscle and travels along the axons of the sensory neuron to the spinal cord. Since this reflex arc is of the disynaptic type, the impulse bifurcates, one part hits the extensor motor neuron to maintain the length of the muscle, and the other goes to the flexor motor neuron, and the extensor is inhibited. Each part of the nerve impulse then goes to its corresponding effector. Or, in the spinal cord, a transition is possible to the motor neuron of the knee flexors through inhibitory synapses, which allow changing the length of the muscle, and then along the motor axons to the end plates (effector, skeletal muscle). Two other options are possible: when the excitation is perceived by the flexor receptor, then the reflex passes along the same path.

OFig.2 1. Extensor muscle. 2. Flexor muscle. 3. Muscle receptor. 4. Sensory neurons. 5. Inhibitory interneurons. 6. Motor neuron. 7. Effector

Let's now get acquainted with more complex reflexes.

2. Flexion and cross-extensor reflex.

As a rule, reflex arcs include two or more sequentially connected neurons, i.e. they are polysynaptic.

An example is the protective reflex in humans. When a limb is impacted, it is withdrawn by flexion, for example, in knee joint. The receptors for this reflex arc are located in the skin. They provide movement aimed at removing the limb from the source of irritation.

When a limb is irritated, a flexion reflex occurs, the limb withdraws, and the opposite one straightens. This happens as a result of the passage of an impulse along a reflex arc. We work on the right leg. From the receptor of the right leg, along the axons of the sensory neuron, the impulse enters the spinal cord, then it is sent to four different interneuron circuits. Two circuits go to the flexor and extensor motor neurons of the right leg. The flexor muscle contracts, and the extensor muscle relaxes under the influence of inhibitory interneurons. We pull our leg back. In the left leg, the flexor muscle relaxes and the extensor muscle contracts under the influence of an excitatory interneuron.

FigBlack – inhibitory interneurons; red ones are exciting. 2. Motor neurons. 3. Effects of relaxed flexor and extensor muscles. 4. Effectors of contracted flexor and extensor muscles.

3. Tendon reflex.

Tendon reflexes serve to maintain constant muscle tension. Each muscle has two regulatory systems: length regulation, with the help of muscle spindles as receptors, and tension regulation, with tendon organs acting as receptors in this regulation. The difference between the tension regulation system and the length regulation system, which involves a muscle and its antagonist, is the use of the tendon reflex muscle tone the entire limb.

The force developed by a muscle depends on its preliminary stretching, speed of contraction, and fatigue. Deviation of muscle tension from the desired value is recorded by the tendon organs and corrected by the tendon reflex.

The receptor (tendon) for this reflex is located in the tendon of the limb at the end of the flexor muscle or extensor muscle. From there, the signal travels along the axons of the sensory neuron to the spinal cord. There, the signal can travel along the inhibitory interneuron to the extensor motor neuron, which sends a signal to the extensor muscle to maintain the muscle in tension. The signal can also go to an excitatory interneuron, which sends a signal through the motor axon to the flexor effector to change muscle tension and perform a certain action. In the case when excitation is perceived by the flexor receptor (tendon), the signal passes through the axon of the sensory neuron to the interneuron, and from there to the motor neuron, which sends a signal along the axons of the motor neuron to the flexor muscle. In the flexor reflex arc, the path is possible only through the inhibitory interneuron.

Fig. Tendon receptor. 2. Sensory neuron. 3. Inhibitory interneuron. 4. Excitatory interneuron. 5. Motor neuron. 6. Receptor.

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