Fish are not capable of forming conditioned reflexes. Higher nervous activity and behavior of fish

Questions about the sensitivity of fish, their behavioral reactions to capture, pain, and stress are constantly raised in scientific specialized publications. Magazines for amateur fishermen do not forget about this topic. True, in most cases, publications highlight personal fabrications about the behavior of a particular species of fish in stressful situations for them.

This article continues the topic raised by the author in the last issue of the magazine (No. 1, 2004)

Are fish primitive?

Until the end of the 19th century, fishermen and even many biologists were firmly convinced that fish were very primitive, stupid creatures that did not have not only hearing, touch, but even developed memory.

Despite the publication of materials refuting this point of view (Parker, 1904 - about the presence of hearing in fish; Tsenek, 1903 - observations of the reaction of fish to sound), even in the 1940s, some scientists adhered to the old views.

It is now a well-known fact that fish, like other vertebrates, are perfectly oriented in space and receive information about their surroundings. aquatic environment using the organs of vision, hearing, touch, smell, taste. Moreover, in many ways the sensory organs of “primitive fish” can compete even with the sensory systems of higher vertebrates and mammals. For example, in terms of sensitivity to sounds ranging from 500 to 1000 Hz, the hearing of fish is not inferior to the hearing of animals, and the ability to detect electromagnetic vibrations and even use their electroreceptor cells and organs for communication and exchange of information is generally a unique ability of some fish! And the “talent” of many species of fish, including the inhabitants of the Dnieper, to determine the quality of food thanks to... the fish touching the food object with the gill cover, fins and even the caudal fin?!

In other words, today no one, especially experienced amateur fishermen, can call representatives of the fish tribe “stupid” and “primitive” creatures.

Popular about the nervous system of fish

The study of the physiology of fish and the characteristics of their nervous system and behavior in natural and laboratory conditions has been carried out for a long time. The first major studies of the sense of smell in fish, for example, were carried out in Russia back in the 1870s.

The brain of fish is usually very small (in pike, the brain mass is 300 times less than body weight) and is structured primitively: the forebrain cortex, which serves as an associative center in higher vertebrates, bony fish completely undeveloped. In the structure of the fish brain, a complete separation of the brain centers of different analyzers is noted: the olfactory center is forebrain, visual - average, the center for the analysis and processing of sound stimuli perceived by the lateral line, - cerebellum. Information received by different fish analyzers at the same time cannot be processed comprehensively, so fish cannot “think and compare,” much less “think” associatively.

However, many scientists believe that bony fish ( which includes almost all of our fresh water inhabitants - R.N. ) have memory- the ability for imaginative and emotional “psycho-nervous” activity (though in its most rudimentary form).

Fish, like other vertebrates, due to the presence of skin receptors, can perceive various sensations: temperature, pain, tactile (touch). In general, the inhabitants of the kingdom of Neptune are champions in the number of unique chemical receptors they have - taste kidneys. These receptors are the endings of the facial ( presented in skin and on antennae), glossopharyngeal ( in the oral cavity and esophagus), wandering ( in the mouth on the gills), trigeminal nerves. From the esophagus to the lips, the entire oral cavity is literally strewn with taste buds. In many fish they are located on the antennae, lips, head, fins, and scattered throughout the body. Taste buds inform the owner about all substances dissolved in water. Fish can sense taste even in those parts of the body where there are no taste buds - with the help of... their skin.

By the way, thanks to the work of Koppania and Weiss (1922), it became clear that in freshwater fish (golden crucian carp) regeneration of a damaged or even cut spinal cord is possible with complete restoration of previously lost functions.

Human activity and conditioned reflexes of fish

They play a very important, almost dominant, role in the life of fish. hereditary And non-hereditary behavioral reactions. Hereditary ones include, for example, the obligatory orientation of fish with their heads towards the current and their movement against the current. Of non-hereditary ones are interesting conditional And unconditioned reflexes.

Throughout its life, any fish gains experience and “learns.” Changing her behavior in any new conditions, developing a different reaction is the formation of a so-called conditioned reflex. For example, it was found that when experimentally catching ruffe, chub, and bream with a fishing rod, these freshwater fish developed a conditioned defensive reflex as a result of 1-3 observations of catching fellow members of the school. Interesting fact: it has been proven that even if the same bream does not come across any fishing gear on its way over the next, say, 3-5 years of its life, the developed conditioned reflex (catching its brothers) will not be forgotten, but will only be slowed down. Having seen how a spotted fellow “soars” to the surface of the water, a seasoned bream will immediately remember what to do in this case - run away! Moreover, to disinhibit the conditioned defensive reflex, only one glance will be enough, and not 1-3!..

One can cite a huge number of examples where the formation of new conditioned reflexes in relation to human activity was observed in fish. It is noted that due to the development of spearfishing, many large fish They knew exactly the firing distance of the underwater gun and did not allow the underwater diver to approach them closer than this distance. This was first written about by J.-I. Cousteau and F. Dumas in the book “In a World of Silence” (1956) and D. Aldridge in “Underwater Hunting” (1960).

Many fishermen know very well that fish very quickly develop defensive reflexes to hooking gear, to the swing of a rod, to the angler walking along the shore or in a boat, to fishing line, to bait. Predatory fish accurately recognize many types of spinners and have “learned by heart” their vibrations and vibrations. Naturally, the larger and older the fish, the more conditioned reflexes (read experience) it has accumulated, and the more difficult it is to catch it with “old” gear. Changes in fishing techniques and the range of baits used dramatically increase fishermen’s catches for a while, but over time (often even within one season), the same pike or pike perch “master” any new items and put them on their “black list.”

Do fish feel pain?

Any experienced fisherman who fishes different fish from a reservoir can already tell at the hooking stage which inhabitant of the underwater kingdom he will have to deal with. Strong jerks and desperate resistance of the pike, powerful “pressure” to the bottom of the catfish, virtual absence of resistance of the pike perch and bream - these “ Business Cards“Fish behavior is determined immediately. There is an opinion among fishing enthusiasts that the strength and duration of a fish’s fight directly depends on its sensitivity and the degree of organization of its nervous system. That is, it is implied that among our freshwater fish there are species that are more highly organized and “nervous-sensual,” and that there are also “coarse” and insensitive fish.

This point of view is too straightforward and essentially incorrect. To know for sure whether our inhabitants of reservoirs feel pain and how exactly, let’s turn to the rich scientific experience, especially since in the specialized “ichthyological” literature, since the 19th century, detailed descriptions features of the physiology and ecology of fish.

INSERT. Pain is a psychophysiological reaction of the body that occurs when the sensitive nerve endings embedded in organs and tissues are severely irritated.

TSB, 1982

Unlike most vertebrates, fish cannot communicate pain by screaming or moaning. We can judge the pain sensation of a fish only by the protective reactions of its body (including its characteristic behavior). Back in 1910, R. Gopher established that a pike at rest, when artificially irritating the skin (prick), moves its tail. Using this method, the scientist showed that the fish’s “pain points” are located all over the surface of the body, but they were most densely located on the head.

Today it is known that due to the low level of development of the nervous system, pain sensitivity in fish is low. Although, undoubtedly, the caught fish feels pain ( remember the rich innervation of the head and oral cavity of fish, taste buds!). If the hook has pierced the fish’s gills, esophagus, or periorbital region, its pain in this case will be stronger than if the hook had pierced the upper/lower jaw or caught on the skin.

INSERT. The behavior of fish on a hook does not depend on the pain sensitivity of a particular individual, but on its individual reaction to stress.

It is known that the pain sensitivity of fish strongly depends on water temperature: in pike, the speed of nerve impulses at 5ºC was 3-4 times less than the speed of excitation at 20ºC. In other words, fish caught in summer are 3-4 times sicker than in winter.

Scientists are confident that the fierce resistance of pike or the passivity of pike perch and bream on a hook during fishing is only to a small extent due to pain. It has been proven that the reaction of a particular fish species to being caught depends more on the severity of the stress received by the fish.

Fishing as a lethal stressor for fish

For all fish, the process of being caught by an angler and landing them is extremely stressful, sometimes exceeding the stress of escaping from a predator. For anglers who profess the catch-and-release principle, it will be important to know the following.

Stress reactions in the body of vertebrates are caused by catecholamines(adrenaline and norepinephrine) and cortisol, which operate over two different but overlapping periods of time (Smith, 1986). Changes in the body of fish caused by the release of adrenaline and norepinephrine occur in less than 1 second and last from several minutes to hours. Cortisol causes changes that begin in less than 1 hour and sometimes last for weeks or even months!

If the stress on the fish is prolonged (for example, during long-term fishing) or very intense (severe fright of the fish, aggravated by pain and, for example, lifting from great depths), in most cases the caught fish is doomed. She will certainly die within 24 hours, even if released. This statement has been repeatedly proven by ichthyological researchers in natural conditions (see “ Modern fishing", No. 1, 2004) and experimentally.

In the 1930-1940s. Homer Smith diagnosed a lethal stress reaction anglerfish to catch and place it in an aquarium. The frightened fish sharply increased the excretion of water from the body through urine, and after 12-22 hours it died... from dehydration. The fish died much faster if they were injured.

Several decades later, fish from American fish ponds were subjected to rigorous physiological studies. Stress in fish caught during planned activities (transplantation of breeders, etc.) was due to increased activity of fish during pursuit by a seine, attempts to escape from it, and short-term exposure to air. The caught fish developed hypoxia (oxygen starvation) and, if they also experienced loss of scales, the consequences in most cases were fatal.

Other observations (of brook trout) have shown that if a fish loses more than 30% of its scales when caught, it dies on the very first day. In fish that had lost part of their scales, swimming activity faded, individuals lost up to 20% of their body weight, and the fish died quietly in a state of mild paralysis (Smith, 1986).

Some researchers (Wydowski et al., 1976) noted that when catching trout with a line, the fish were subjected to less stress than when they lost their scales. The stress reaction was more intense when high temperatures water and in larger individuals.

Thus, an inquisitive and scientifically “savvy” fisherman, knowing the peculiarities of the nervous organization of our freshwater fish and the possibility of them acquiring conditioned reflexes, learning ability, their attitude to stressful situations, can always plan their vacation on the water and build relationships with the inhabitants of Neptune’s kingdom.

I also sincerely hope that this publication will help many anglers to effectively use the rules of fair play - the “catch and release” principle...

In the Black Sea, as probably in others warm seas, there is an amazing way of amateur fishing “for tyrants”. A fisherman accustomed to cautious and capricious freshwater fish, he's just taken aback when he first gets on sea fishing. The tackle, in other words, the “tyrant” himself, is a long fishing line, to one end of which four or five hooks are attached on short leashes. Nothing else is required - no rod, no bait. The fisherman goes to a deep place, lowers the hooks into the water, and wraps the other end of the fishing line around his finger. He sits in the boat and tugs on the line from time to time until he feels that it has become heavier. Then he drags. And what do you think, he pulls out a fish, and sometimes not one, but two or three at once. True, fish, as a rule, do not take empty hooks into their mouths, but hook onto them with their belly, gills, and even tail. And it still seems that you have to be completely stupid to fall for such a frankly dangerous tackle, and one that does not promise any benefits.

Maybe, indeed, fish are very stupid creatures. Let's try to figure it out. The main criterion of intelligence is the ability to learn. Pisces are diligent students. They easily develop various skills. Everyone can see this for themselves. Many people keep tropical fish at home. In two or three days it is easy to teach the inhabitants of the aquarium to swim up to the glass if you first lightly tap it with your finger and then throw some tasty food there. After fifteen to twenty such procedures, the fish, having heard the call, will drop all their fish activities and rush to the appointed place, hoping to receive a portion of worms for their diligence.

The skills acquired by bees, ants and fish are not similar to those developed by very primitive animals. In terms of their complexity and duration of persistence, they rarely differ from habituation reactions and summation reflexes. The high perfection of the nervous system of these animals allowed them to produce adaptive reactions new type. They are called conditioned reflexes.

It was this type of reflexes that was discovered and studied by I.P. Pavlov on dogs. The name was not given by chance. The formation, preservation or elimination of these reflexes occurs only under special conditions.

For conditioned reflexes to occur, it is necessary that the action of two specific stimuli coincide several times in time. One of them - it is necessary that he act first - should not represent any special significance for the animal, nor frighten him, nor cause a food reaction in him. Otherwise, it makes absolutely no difference what kind of irritant it is. It can be any sound, the sight of any object or other visual stimulus, any smell, heat or cold, touching the skin, and so on.

The second stimulus, on the contrary, must cause some kind of innate reaction, some kind of unconditioned reflex. This could be a food or defensive reaction. After several combinations of such stimuli, the first of them, previously a completely indifferent stimulus for the animal, begins to evoke the same reaction as the unconditioned one. It was in this way that I developed a conditioned food reflex among the inhabitants of my aquarium. The first stimulus, tapping on the glass, was at first absolutely indifferent to the fish. But after it coincided fifteen to twenty times with the action of a food stimulus - ordinary fish food - the tapping acquired the ability to cause a food reaction, forcing the fish to rush to the feeding site. Such a stimulus is called conditioned.

Even in ants and fish, conditioned reflexes remain for a very long time, and in higher animals - almost all their lives. And if the conditioned reflex is trained at least occasionally, it can serve fish indefinitely. However, when the conditions that led to the formation of the conditioned reflex change, if the action of the conditioned stimulus is no longer followed by an unconditioned one, the reflex is destroyed.

In fish, conditioned reflexes are easily formed even without our help. My fish immediately swim out of all corners as soon as I find myself near the aquarium, although no one specially trained them to do this. They know for sure that I will not approach them empty-handed. It’s another matter if there are children crowded around the aquarium. Kids prefer to knock on the glass, scare the inhabitants of the aquarium, and the fish hide in advance. This is also a conditioned reflex, only the reflex is not food, but defensive.

There are many types of conditioned reflexes. Their names emphasize one particular feature of the reaction, developed in such a way that everyone immediately understands what is being said. Most often, the name is given in accordance with the reaction the animal performs. A conditioned food reflex, when a fish swims to the feeding place, and if it hurries to hide in the thick of underwater plants, they say that it has developed a defensive conditioned reflex.

When studying mental abilities fish often resort to developing both food and defensive conditioned reflexes. Usually, a task is invented for the subjects that is a little more difficult than the ability to quickly arrive at the feeding place or hastily escape. Scientists in our country love to force fish to grab a bead with their mouths. If you lower a small red ball tied to a thin thread into the water, it will definitely interest the fish. In general, they are attracted to the color red. The fish will certainly grab the ball with its mouth to taste it, and, tugging on the thread, will try to take it with it, so that somewhere on the side it can calmly figure out whether it is an edible thing or not. A conditioned reflex is developed to light or to a bell. While the fish swims up to the bead, the light is on, and as soon as the bead is in the fish’s mouth, they throw a worm to it. One or two procedures are enough for the fish to constantly grab the bead, but if the development of the reflex continues, it will eventually notice that the worm is being given while the light is on. Now, as soon as the light comes on, the fish will hastily rush to the bead, and the rest of the time will not pay any attention to it. She remembered the connection between the light, the bead and the worm, which means that she developed a food reflex to light.

Pisces are capable of solving more complex problems. Three beads are dropped into the aquarium next to the gudgeon at once, and a simple picture is attached to the glass outside against each of them, for example a black triangle, the same square and a circle. The minnow, of course, will immediately become interested in the beads, and the experimenter closely monitors his actions. If they are going to develop a conditioned reflex to a circle, then as soon as the fish swims up to this picture and grabs the bead hanging opposite it, they throw a worm at it. The pictures are constantly swapped during the experiment, and soon the gudgeon will understand that the worm can only be obtained by pulling the bead hanging opposite the circle. Now he will not be interested in other pictures and other beads. He developed a conditioned food reflex to the image of a circle. This experience convinced scientists that fish are able to distinguish between pictures and remember them well.

To develop a defensive conditioned reflex, the aquarium is divided into two parts by a partition. A hole is left in the partition so that the fish can move from one part to another. Sometimes a door is hung over the hole in the partition, which the fish can easily open by pushing it with its nose.

The reflex is developed according to the usual scheme. A conditioned stimulus is turned on, for example a bell, and then the electric current is turned on for a moment and the current is continued to stimulate the fish until it decides to open the door in the partition and move to another part of the aquarium. After several repetitions of this procedure, the fish will understand that soon after the bell begins to sound very unpleasant and painful effects await it, and, without waiting for them to begin, it hastily swims away behind the partition. Conditioned defensive reflexes are often developed faster and last much longer than food ones.

In this chapter, we met animals that develop conditioned reflexes well. In terms of their mental development, animals are approximately the same. True, some of them, namely social insects, are the highest representatives of their branch of the animal kingdom, the highest link in the development of arthropods. Among arthropods, none are smarter than bees, wasps, ants and termites. Another thing is fish. They stand at the very first steps of the development of their branch - vertebrates. Among them, they are the most primitive, underdeveloped creatures.

Both ants and fish are capable of learning and are able to notice patterns in the world around them. Their learning and familiarization with various natural phenomena proceeds through the formation of simple conditioned reflexes. For them this is the only way to understand the world.

All accumulated knowledge is stored in their brain in the form of visual, sound, olfactory and taste images, that is, as if duplicates (or copies) of those impressions that formed at the moment of perception of the corresponding stimuli. The light came on above the aquarium and revived in the animal’s brain the image of a bead, the image of its own motor reactions, the image of a worm. Obeying this chain of images, the fish swims up to the bead, grabs it and waits for the due reward.

The peculiarity of the knowledge acquired by animals through the formation of simple conditioned reflexes is that they can notice only those patterns of the surrounding world that are of direct importance to them. The gudgeon will certainly remember that after a flash of light, under certain conditions, tasty food may appear, and after the sound of a bell, you will feel pain if you do not immediately move to another room. For my pet fish, it is completely indifferent to what I am wearing when I approach their aquarium, since this is not associated with any special benefits or troubles, and they do not pay attention to my clothes. But my dog instantly perks up as soon as I go to the coat rack and take my coat. She has long noticed that I go outside in a coat, and every time she hopes that she will be taken for a walk.

Conditioned reflexes are easily formed and persist for a long time, even if they are not trained, but they can just as easily be destroyed and destroyed. And this is not a defect, but a great advantage of conditioned reflexes. Due to the fact that it is possible to make changes to developed reflexes and even destroy them, the knowledge acquired by the animal is constantly being refined and improved. The experimenters stopped throwing worms into the aquarium after a flash of light, and lo and behold, after a few days the crucian carp stopped grabbing the bead. The reaction became useless, they stopped giving rewards for it, and the conditioned reflex, as scientists say, died out. They stopped giving the gudgeon a worm when it tugs on a bead hanging opposite the circle, and the conditioned reflex will soon fade away. They began to give food when he grabbed a bead hanging against the square, and the fish developed a new conditioned reflex.

WITH early childhood and until old age, the animal can form more and more new conditioned reflexes, and those that have become unnecessary are extinguished. Thanks to this, knowledge is constantly being accumulated, refined and polished. Animals really need them, helping them find food, escape from enemies, and, in general, survive.

Municipal institution "Kamenskoye Department of Public Education"

District competition research work

and projects for junior schoolchildren “Debut in Science”

Municipal educational institution "Kamenskaya secondary school No. 3"

Class 5

Direction: the world

RESEARCH

Development of conditioned reflexes in aquarium fish guppies

Head: Yatskova Elena Aleksandrovna

Biology teacher of the 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 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 discovered 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 repetition similar experiences Just the sight of a light bulb alone, 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 of the organism with 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 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. Ground color in natural conditions served as a safety signal to the fish, since only when they got 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 this case, the 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 lighting conditions. 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 . For better comparison indicators of conditioned reflex activity of different animal species use natural food-procuring movements. 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 places habitats and many species 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 a home aquarium, it 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 a 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 clock signaled mobile phone and turning on the light, 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. development of a conditioned reflex to red and blue colors (feeding after the appearance of a box with a red lid or 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 and most of the fish will 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

An aquarium is a small world that 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 of the 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.: graduate School, 1988. - 368 p.

Mikhailov V.A. All about guppies and other viviparous animals. Popular fish. 2nd edition, revised and enlarged. - 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 the general editorship of academician. 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 – 239 p.

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

Zaletova V.D. 1

Tavchenkova O.N. 1

1 Municipal autonomous educational institution "Secondary comprehensive school No. 5 of Chelyabinsk", MAOU "Secondary school No. 5 of Chelyabinsk"

The text of the work is posted without images and formulas.
Full version work is available in the "Work Files" tab in PDF format

Introduction

Many people are mistaken in thinking that fish are stupid and unresponsive creatures. Indeed, some people initially purchase an aquarium as a purely decorative item. However, observing fish, many aquarists come to the conclusion that fish are not just interior decoration, they are living creatures, interesting in their behavior. Relevance The work is that the experiment on developing a conditioned reflex in aquarium fish teaches us to be attentive to living beings that inhabit the world around us, helps us to establish ways of interaction with living organisms. This knowledge, in turn, gives us the opportunity to make the living environment more comfortable and respond to the needs of those whose lives depend on our behavior.

Target work: to study the development of a conditioned reflex in different types of aquarium fish.

An object research: aquarium fish.

Item research: conditioned reflexes in fish.

Hypothesis research: suppose that with the help of the knowledge obtained during the experiment, it is possible to develop conditioned reflexes of fish.

In accordance with the goal and hypothesis, the following tasks:

study the behavior of fish, their conditioned and unconditioned reflexes;

identify and describe the fish that live in my aquarium;

conduct experiments on the development of conditioned reflexes in fish.

The following were used in this work: methods research: study scientific literature and Internet materials, description, observation, analysis.

Theoretical significance The idea of the work is that its results can be presented in lessons about the surrounding world when studying fish.

We believe that the results of the study have practical significance- assistance in organizing the most comfortable habitat for aquarium fish.

Fish behavior. Conditioned and unconditioned reflexes

Fish are vertebrates that live in water. The living conditions of fish and their behavior are interconnected. Each species of fish has innate and acquired reactions to the environment. The level of development of these reactions is determined by the degree of development in the process of evolution of the senses and central nervous system.

The activity of all body organs in fish and the body as a whole is regulated by the nervous system. It consists of nervous tissue, the brain and spinal cord.

The fish brain consists of the olfactory parts, the forebrain hemispheres, the diencephalon with the pituitary gland, the visual parts (midbrain), the cerebellum and the elongated brain.

Fish have a well-developed memory; they can remember their owners and distinguish them from other people.

Great importance In the life and behavior of fish, vision is important. Surely everyone has noticed that when you bring food, the fish immediately perk up and follow the movement of your hand. The cornea of the fish's eye is slightly convex, the lens is spherical, and there are no eyelids. The pupil is unable to contract and enlarge. Due to the contraction of the muscles of the falciform process, the lens of the eye can move back, thus achieving adaptation and adjustment of the vision of fish. Fish are distinguished by the brightness of light and select the most optimal zones for a given species. Most fish see the tone of the object.

The olfactory organs of fish are located in the nostrils, which are simple depressions with a mucous membrane penetrated by branching nerves coming from the olfactory part of the brain. With the help of signals coming through the nostrils, the fish can capture the aroma of food or an enemy at a fairly decent distance.

The taste organs of fish are represented by taste buds. It is curious that in most types of fish papillae are located not only in the mouth, but also on the antennae, head and sides of the body, right up to the caudal peduncle.

Many fish have a well-developed sense of touch, especially the majority of bottom-dwelling fish and inhabitants. muddy water. The antennae of fish are their organs of touch. With their antennae, fish feel various objects and animals, detect food, and navigate the area.

Fish do not have an external ear. The hearing organs are represented by the inner ear. The inner ear consists of three semicircular canals with ampoules, an oval sac, and a round sac with a projection (lagena). Sounds enable fish to navigate the waters, detect food, escape from opponents, and attract individuals of the opposite sex.

Despite the famous saying, fish are not that dumb. Of course, it is unlikely that fish will be able to please us with melodic harmonies. A person can clearly hear the sounds made by some fish at a great distance. Sounds vary in pitch and intensity. Typically, fish use sound signals during the breeding season.

The skin of the lateral surface contains a unique sensory organ - the lateral line. Typically, the lateral line is a system of depressions or channels in the scalp and body with nerve endings in the depths. The entire system is connected by nerves to the inner ear. It is designed to perceive low-frequency vibrations, which makes it possible to detect moving objects. Thanks to the line, the fish acquires data about the flow and direction of the water, its chemical composition, pressure, “feels” infrasounds.

Pisces exchange data and do this using a variety of signals: sound, visual, electrical and others. For fish that live in schools, interaction is necessary: it can help discover food, escape from predators, select a mate, and carry out other activities that are important to fish.

Types of aquarium fish to observe

Guppy(lat. Poecilia reticulata) - freshwater viviparous fish. The size of males is 1.5-4 cm; slim; purebred individuals often have long fins; the color is often bright. The size of females is 2.8-7 cm; 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.

Very peaceful and able to get along with different types fish It is only important to take into account the impossibility of guppies living alone for a long time. Therefore, these fish must be placed in the aquarium in pairs or groups. Optimal constant temperature water is in the range +24-26 °C.

Guppies are unpretentious, but they can reach maximum flowering only under favorable conditions. The offspring of the most thoroughbred parents in poor conditions will not achieve either their brightness or their luxuriance of fins. Guppies can live in a glass of water, but this is more of an existence than a life.

Sumatran aquarium fish barb(lat. Puntius tetrazona, and formerly Barbus tetrazona), this is a bright and active fish that will enliven any biotope. This is a small fish, with a yellowish-red body and black stripes, for which English language it even received the name tiger barb.

It is easy to maintain and is great for aquarists of all levels. They are quite hardy, provided the water is clean and the aquarium is in balance. In an aquarium with Sumatran barbs, it is better to plant a lot of plants, but it is important that there is also free space for swimming. However, they can nibble on tender shoots of plants, although they do this quite rarely. Apparently, there is not enough plant food in the diet.

The Sumatran barb has a tall, rounded body with a pointed head. These are small fish, in nature they grow up to 7 cm, in an aquarium they are somewhat smaller. With good care they live up to 6 years. The body color is yellowish-red, with very noticeable black stripes. The fins are colored red. Also at this time their muzzle turns red.

They eat all types of live, frozen or artificial food. It is advisable to feed him the most varied food to maintain the activity and health of the immune system. For example, the basis of the diet can be high-quality flakes, and additionally provide live food - bloodworms, tubifex, brine shrimp and coretra. It is also advisable to add flakes containing spriulina, as they can spoil the plants.

Aquarium fish neon blue or ordinary (lat. Paracheirodon innesi) has long been known and very popular. With its appearance in 1930, it created a sensation and has not lost its popularity to this day. A flock of blue neons in an aquarium creates a mesmerizing view that will not leave you indifferent. These are the factors that made it so popular.

Neons feel most comfortable in a flock of 6 or more individuals; it is in this group that the brightest colors are revealed. Neons are very peaceful and desirable residents of community aquariums, but they should only be kept with small and equally peaceful fish. Small size and peaceful disposition, good helpers against predatory fish!

Neon is distinguished primarily by a bright blue stripe running across the entire body, which makes it very noticeable. And in contrast to it, there is a bright red stripe, which starts from the middle of the body and goes to the tail, slightly extending onto it.

The blue neons themselves are wonderful and peaceful fish. They never bother anyone, they get along with everyone peaceful fish. But they can just become victims of other fish, especially if it is a large and predatory fish such as swordmouth or green tetradon. Can be kept with large, but not predatory fish, for example, angelfish. What fish do neons get along with? With guppies, platies, cardinals, swordtails, rainbows, barbs and tetras.

Betta fish or cockerel(lat. Betta splendens), unpretentious, beautiful, but can kill the female and other males. It is a typical labyrinth fish, meaning it can breathe atmospheric oxygen. It was the aquarium betta, and even its relative, the macropod, that were one of the first aquarium fish that were brought to Europe from Asia. But long before this moment, betta fish were already bred in Thailand and Malaysia.

The fish gained popularity for its luxurious appearance, interesting behavior and the ability to live in small aquariums. It is also easy to breed and just as easy to cross, resulting in many color variations, different in everything from color to fin shape.

The Betta is simply great for beginners and those aquarists who cannot afford a large aquarium. He needs the bare minimum, both in volume and nutrition. It is also unpretentious, strong, and is always on sale. Due to its labyrinthine apparatus, it can survive in water poor in oxygen and in very small aquariums.

It is very easy to distinguish males from females in bettas. The male is larger, brighter colored, and has larger fins. Females are paler, smaller, have small fins, and their abdomen is noticeably rounder. In addition, she behaves modestly, trying to stay in secluded corners and not catch the eye of the male.

Development of conditioned reflexes in aquarium fish

In the development of conditioned reflexes, fish belong to the most primitive vertebrates. However, various members of this class provide us with remarkable examples of complex behaviors that are worth exploring.

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

1. Feed the fish at different times, otherwise a conditioned reflex will develop.

2. The conditioned stimulus (knock, light) should act first.

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, when a conditioned stimulus appears, swim to the place where they receive food.

6. When developing different reflexes, the place of feeding must be changed.

Experiment 1. Development of a conditioned food reflex when a foreign object approaches.

Rice. 1. Feeding with tweezers

This means that the fish have developed a conditioned reflex to tweezers as a stimulus that coincides with the unconditioned stimulus—food. In this case, the tweezers serve as a food signal.

Experience result:

In this experiment, tweezers serve as a food signal. The formed reflex can persist even in the absence of feeding, but without food reinforcement it begins to slow down and fades away (Table 1).

Table 1

Results of observations of feeding with tweezers

started the experiment on September 18, 2017.

aquarium fish
aquarium fish

Conclusion: The conditioned reflex is developed on the basis of the unconditioned, having a leading influence of the conditioned stimulus - tweezers. In the fish brain between the visual and food zones the cerebral cortex, a temporary connection is established.

In barb fish, the conditioned reflex “Response to tweezers” was developed faster than in other inhabitants of our aquarium. Snails do not react to tweezers.

Experiment 2. Development of a conditioned food reflex “Reaction of fish to sound stimuli.”

As you know, fish have neither an outer nor a middle ear. Their organ of hearing (and balance) is only the inner ear, which is characterized by a relatively simple structure. The endings of the auditory nerve approach the inner ear. The question of whether fish hear or are deaf has long been controversial. Now it can be considered proven that fish perceive sounds, but only if the latter passes through water. Essentially, fish cannot detect sound as air vibrations: for this it would be necessary to have a more complex hearing apparatus (tympanic membrane, auditory ossicles), which in the process of evolution appeared only in amphibians, but is absent in fish. Fish are able to perceive sound vibrations arising in the air in the form of vibrations of water particles if they move under the influence of impacts of air sound waves. Therefore, fish hear differently than land animals. Outside the water, fish become deaf and do not react even to the strongest sounds. We conducted an experiment to develop a conditioned reflex to tapping, accompanying the feeding of fish with light blows with a hard object against the walls of the aquarium ( figure 2).

Rice. 2. Feeding with tapping

Experience result:

As a result, for about a week, with just tapping (without feeding), the fish swim to the place where they usually received food ( table 2).

table 2

Results of tapping feeding experiment

started the experiment on September 26, 2017.

aquarium fish	Time for fish to approach food (seconds)
aquarium fish

Conclusion: In fish of the barb and neon species, the conditioned reflex “Feeding with tapping” was developed faster than in fish of other species. There is no reaction of feeding with tapping in snails. The knocking reflex was developed in fish on the 6th day.

Experiment 3. Development of a conditioned food reflex with a light stimulus.

The development of the eyes, their size and position on the head of the fish are directly dependent on its living conditions. For example, in bottom-dwelling fish that watch the approaching prey from below, the eyes are located on the top of the head (catfish); in fish lying on the bottom on one side, the eyes move to the side of the body that faces upward (flounder). In conditions deep sea habitat where light almost does not penetrate, the fish’s visual organs are either reduced or increased in size. In the first case, this is the result of a decrease in visual function, and in the second, it is an increase. With complete loss of vision in some deep sea fish The photosensitivity of their skin increases as a compensatory adaptation to orientation in the specific conditions of the dimly lit zone of the reservoir. In some cases, the development of luminous organs in deep-sea fish has the same biological significance, although their role is not limited to this. It should be noted that fish have a positive reaction to light. They swim to places that are well lit by the sun. Their natural food is concentrated here - numerous small crustaceans that feed on phytoplankton (free-floating algae, the life of which depends on solar radiation). Since plankton, as an unconditional food stimulus, acted on fish every time in combination with sunlight, the latter received the value of a food signal in their lives ( figure 3) .

Rice. 3. Feeding with a light stimulus

We conducted an experiment on feeding fish in the presence of a light stimulus: every time we fed, we turned on the light in the aquarium.

Experience result:

One must think that at first the fish developed a conditioned food reflex to light, but over time, repeating itself many times over a number of generations, this reflex was inherited and turned into an innate biologically useful reaction - phototaxis, which became a means for fish to find food. This phototaxis Lately successfully used in fishing, attracting fish with the help of electric lamps and other light sources. Commercial exploration using light also gives good results. In this case, a person controls the historically established instinct of fish (the desire for light) in his own interests to the detriment of their life, which indicates relative character expediency of innate reactions ( table 3).

Table 3

Results of feeding experiment with light stimulus

started the experiment on 10/01/2017

aquarium fish	Time for fish to approach food (seconds)
aquarium fish

Conclusion: Barb and betta fish react to light faster than other fish. There is no reaction to feeding with light in snails, a weak reaction in guppies.

Conclusion

As a result of the work done, it turned out that the aquarium is a small world, providing a unique opportunity to bring a piece of nature into the house, where everything is coordinated, lives in harmony, develops, changes, revealing itself to the observer.

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. Aquarium fish can develop all sorts of conditioned reflexes to various stimuli: time, light, color and shape of objects, etc.

During the experiment, we made the following conclusions.

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

During the experiment, conditioned reflexes were developed in the aquarium fish guppy, barb, neon, and cockerel to sound, light, and feeding from tweezers.

Fish develop a reflex to sound faster than others.

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

The degree of response and learning ability differ significantly among representatives of different families and even species of aquarium fish. When studying the behavior of fish in an aquarium, the level of adaptation in species such as barb, betta and neon turns out to be high. Aquarium snails have absolutely no reactions to external stimuli.

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

Thus, the research hypothesis that we can develop conditioned reflexes in fish was confirmed, the goal and objectives of the study were fulfilled.

This paper examines an example of the development of only some conditioned reflexes. The acquired knowledge gives rise to a wide range of opportunities for scientific knowledge of the laws of nature and improving one’s own knowledge.

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. In the future, I would like to continue observing the fish, try to develop new reflexes in them, and learn to understand their needs.

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.

Bibliography

Ziper, A.F. Control of the behavior of animals and birds. Reflexes in the life of animals [Text]. - Access mode: http://fermer02.ru/animal/296-refleksy-v-zhizni-zhivotnykh.html

Pleshakov, A.A. From earth to sky. Atlas-identifier: book. for beginning students class [Text] / A.A. Pleshakov. - M.: Education, 2016. - 244 p.

Rules for the development of conditioned reflexes [Text]. - Access mode: http://www.medicinform.net/human/fisiology8_1.htm

Sereev, B.F. Entertaining physiology [Text] / B.F. Sergeev. - M.: Bustard, 2004. - 135 p.

I explore the world: Children's encyclopedia: Animals [Text, drawing]. - M.: LLC "AST Publishing House", 2001. - 223 p.

STUDYING THE BEHAVIOR AND ADAPTATION OF FISH TO EXTERNAL CONDITIONS

The study of fish behavior is one of the most important tasks of ichthyology and an endless field for conducting the most interesting and fascinating experiments and research. In particular, preserving stocks of valuable anadromous and semi-anadromous fish in connection with hydraulic construction is impossible without successfully studying the behavior of these fish on spawning grounds, in the area of dams and fish passage structures. It is equally important to prevent fish from being sucked into water intake structures. For these purposes, devices such as bubble curtains, electric fish barriers, mechanical screens, etc. are already used or have been tested, but so far the devices used are not sufficiently effective and economical.

For the successful development of the fishery and the improvement of fishing gear, information about the behavior of fish in the fishing zone, dependence on hydrometeorological conditions and hydrological factors, and daily and periodic vertical and horizontal migrations is extremely important. At the same time, rational organization of fishing is not possible without studying the distribution and behavior of groups of different ages. The timing and power of migrations, fish approaches to spawning, feeding, and wintering sites are largely determined by changes in environmental conditions and the physiological state of individuals.

The importance of the senses in the perception of abiotic and biotic signals

The study of fish behavior is carried out on the basis of regular field observations, experiments in laboratory conditions and analysis of data on the interaction of the higher nervous activity of the studied objects with the external environment. In the process of interaction with environment Fish exhibit three modes of orientation:

Direction finding - reproduction of a signal coming from outside world;

Location - sending signals and perceiving their reflections;

Signaling is the sending of a signal by some individuals and their perception by others.

The perception of abiotic and biotic signals that influence the behavior of fish occurs through the senses, among which are primarily vision, hearing, lateral line, and smell. Of particular importance is reflex activity fish

Fish vision

Compared to the air, water, as a habitat for fish, is less favorable for visual perception. Illumination of water layers penetrating into water sunbeams is directly dependent on the amount of dissolved and suspended particles, which cause the turbidity of the water and determine the limits of action of the fish’s visual organs. IN sea water illumination reaches a depth of 200-300 m, and in fresh water bodies only 3-10 m. The deeper the light penetrates into the water, the deeper the plants penetrate. Water clarity varies enormously. It is greater away from the coast and decreases in the inland seas. The more living organisms in the water, the less transparent the water. Very clear waters of the seas, especially a beautiful deep blue color, are waters poor in life. The most transparent seas- Sargasso and Mediterranean.

Pisces have color vision. For individuals living in the illuminated area, it is very important and determines their behavior. The feeding of planktivores, including juvenile fish, is carried out thanks to well-developed organs of vision. The visual acuity inherent in fish allows, depending on the illumination and transparency of the water, to distinguish objects at a distance of up to several tens of meters. All of the above is of great importance for the nutritional and defensive reactions of fish. It has been proven that the formation and disintegration of schools is also related to the illumination of the aquatic environment.

The movement of fish against the current is controlled by the organs of vision, and less often by the organs of smell. This is the basis for attempts to direct fish in fish ladders following the models. WITH Rhythms and feeding activity are related to illumination.

The phenomenon of vertical zonality and the predominant color of animals and plants is due to the uneven penetration of rays of different wavelengths into the water column. Animals are very often colored in the color of that part of the spectrum that penetrates to a given depth, as a result of which they acquire a protective coloring and seem invisible. In the upper horizons, animals are mostly colored brownish-greenish, and deeper - red. At great depths, devoid of light, animals are mostly colored black or completely devoid of color (depigmented).

Hearing.

The acoustic properties of water are much stronger than air environment. Sound vibrations travel faster and penetrate further. It has been established that the role of sound signaling increases with the onset of twilight, as visual perception decreases. The center of sound perception is the inner ear of fish. Ultra perception sound vibrations This is not typical for fish, but they do react to low-frequency sounds. The reaction to ultrasound is detected only when exposed to a powerful source at a short distance and can most likely be attributed to pain skin.

When there is a reaction to sound signals, fish react directionally (reflexively), first of all, to food stimuli or a danger signal. Within the city limits, fish quickly get used to noise, even constant very loud sounds. This may be why it was not possible to organize the directed movement of salmon into rivers or scare them away from sewage using sound signals. Even near airfields, the fish do not change their behavior and continue to bite the bait. It has been noted that intermittent sound has a stronger effect on fish than constant sound.

Side line

First of all, it should be noted the functional connection of the lateral line with the hearing organs. It has been established that the lower part of sound vibrations (frequencies 1-25 Hz) is perceived by the lateral line. The significance of the lateral line has not been fully studied. The main function of the lateral line is the perception of hydrodynamic fields and jets of water. Hydrodynamic fields from large sources, causing a defensive reaction in fish, are usually perceived at a considerable distance. However, in areas where fast currents form in rivers below the dam, many fish quickly get used to the changed conditions.

Hydrodynamic fields caused by the movement of small bodies usually cause a feeding reaction in fish. With the help of the lateral line, fish are precisely oriented for an aimed throw over a relatively short distance of several tens of centimeters.

With the help of the lateral line, twilight, nocturnal and thicket predators orient themselves when reaching prey. For juvenile fish and planktivores, the lateral line serves to detect predators and general orientation in the environment.

Smell of fish

The property of water as a good solvent should be taken into account. It has been established that fish react to negligible amounts of substances dissolved in water. Fishermen use scents to attract fish. At the same time, other substances, such as tincture of the skin of predatory fish and marine mammals, act as a deterrent.

The perception of substances dissolved in water is apparently associated with the taste organs. Migratory fish find their way from the sea to rivers using their sense of smell. There is no doubt that fish are capable of remembering. This explains homing(from English home - ≪house≫) - the ability of fish to enter exactly those rivers, channels or rivers from which they emerged as fry after developing from eggs.

Higher nervous activity and behavior of fish

The ability of fish to acquire conditioned reflexes in combination with unconditioned reflexes makes it possible to control their behavior. Conditioned reflexes are developed in fish more slowly than in higher vertebrates, and quickly fade away if they are not reinforced by the same factors that contributed to their formation, but are capable of spontaneously arising after a certain time.

Water temperature plays a special role in the creation and extinction of reflexes. There is evidence (Yudkin, 1970) that sturgeons develop conditioned reflexes in the fall much worse than in the summer. In goldfish, a decrease in water temperature below +13 °C and an increase above +30 °C caused the disappearance of all previously acquired reflexes. All this becomes quite understandable if we consider that the vital activity of fish, animals with a low blood temperature, depends on the temperature of the water.

Conditioned reflexes can arise in fish in the form of imitation. Untrained fish imitate others whose conditioned reflexes have been formed after appropriate training or life experience. Very indicative in this regard is the change in fish behavior in the fishing zone of active and even stationary fishing gear. Often, one individual that has discovered a loophole to exit the fishing gear is enough for most of the flock to leave it (for example, anchovy in fixed and cast nets).

Pilengas is capable of overcoming net formations, waddling over the top fence, jumping out and even crawling, wriggling along an inclined surface when retrieving cast nets.

Observer pilots, who for a long time were engaged in guiding fishing vessels to schools of fish, noted a gradual change in the behavior of anchovy: a change in the direction of movement and exit from purse seines, “squatting,” dispersing, etc.

The behavior and speed of reactions of fish in different physiological states are not identical. Fatty fish quickly form aggregations that are more persistent than those formed by physiologically weakened individuals. Often fish react not only to sudden changes in conditions, but also to emerging trends in changes in environmental factors. With a slight increase in water temperature, accumulations may simply disintegrate, despite the fact that the temperature will remain within the optimal range for fishing.

The formation of fish in schools is of great importance. The defensive value of a flock of fish is as great as that of birds. Also, covering a larger area of water, the school quickly finds feeding areas than individual individuals.

Observations have shown the presence of vertical migrations in some fish species. Thus, on the Newfoundland bank, at sunset, sea bass rises from depths of 500-600 m to depths of 300-400 m within 60-90 minutes. At night, the perch stays 200 m from the surface, and by morning it descends and is at the bottom during the day. Cod and haddock behave in a similar way. In the Black Sea, vertical migrations are most characteristic of anchovy and horse mackerel, descending to the lower horizons during the daytime and rising to the surface at night. This behavior is associated with the movement of plankton. For many fish, being at different depths and at different distances from the shore is typical during different periods life cycle.

All of the above is directly related to the behavior of fish. This must be taken into account by the researcher to more effectively influence the behavior of fish in fishing areas, where it is necessary to identify the leading factors for each specific case. Currently, knowledge of behavioral characteristics is of particular importance for the successful development of the fishery. And this is due, first of all, to an increase in fishing intensity, a fall in stocks and an increase in the economic cost of performing work.

The study of behavioral characteristics depending on environmental factors and the physiological state of fish allows researchers and fishermen to tactically regulate fishing and increase its efficiency. Knowledge of the biology of a commercial object allows fishing to be organized during periods of maximum concentrations, at depths of greatest distribution and at water temperatures when aggregations are most stable. One of the tools for such research is multifactorial correlative analysis of the most significant relationships between oceanological and biological criteria for constructing mathematical models, describing the phenomena and processes of the life cycle of fish. For a long time and well in a number of basins, forecasts of the timing of autumn migrations, the formation and collapse of wintering aggregations and the beginning of mass fishing have proven themselves. commercial fish. This helps reduce unproductive vessel downtime and increase fishing intensity.

As examples of such models, one can cite the regression equations calculated at AzNIIRKh to predict the timing of the autumn migration of the Azov anchovy through the Kerch Strait to the Black Sea.

Start of turn:

Y = 70.41 +0.127 X 1, -0.229 X 2,

Y = 27.68-0.18 X 2 - 0.009 (N).

Beginning of mass migration:

Y, = 36.01 +0.648 X 3 -0.159 X 2,

where U and U 1 are the dates of the expected beginning of autumn migration and mass movement (counting from September 1); X 1 and Xs - dates of the final transition of water temperature through +16 and +14 °C (respectively) in the southern part Sea of Azov(counting from September 1); X 2 is the number of fish (in%) in the population with a body condition coefficient of 0.9 or more as of September 1, N is the duration of feeding (degrees/days) after spawning on September 1.

The error in forecasting the timing of the start of migrations according to the presented models does not exceed 2-3 days.

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