About fish taste and charm. Fish angle

How do fish feel?

The answer to this question has not yet been fully clarified; for example, it has not yet been reliably determined whether fish feel pain, and if so, how much.
But, nevertheless, knowledge of the structure and functions of their receptors allows us to draw certain conclusions about fish sense organs: this is, first of all, smell, taste, spatial orientation, hearing. Like humans, fish have all senses that are closely interconnected. Fish receptors register stimuli of both physical and chemical nature: pressure, sound, temperature, color, electric and magnetic fields, smell, taste.

Smell- one of the most important ways of understanding the world in fish. Experienced fishermen always sprinkle the bait on the hook with aromatic bait: many fish are very sensitive to odors.
The fish nose has special olfactory sacs with cilia. By narrowing and expanding these bags, the fish sniffs. Thanks to their sense of smell, fish distinguish food, find their school, partners during spawning, predators and prey. In addition, in some situations, fish can release “chemical signals” into the water (for example, when there is danger), which are also recognized by other fish. This is a very significant factor for fish living in turbid water, since collecting information through touch or sounds is difficult there, and fish actively use their sense of smell.

The sense of smell is especially well developed in migratory swimmers. For example, juveniles sockeye salmon using the sense of smell, distinguishes the water of different lakes, solutions of various amino acids, and the concentration of calcium in water; european eel, migrating from Europe to spawning grounds located in the Sargasso Sea, can determine the water of any of the reservoirs encountered on its way.
In general, “chemical olfactory signals” play an important function in the life of fish: they come in different types. For example, signals “for our own” are called pheromones. The relationships between different fish species are determined kairomones And allomones. Kairomons carry information useful to the species receiving the signal. Allomons on the contrary, they cause a behavioral response that is beneficial for the species that produced the signal.

The fish has four nostrils in its nose, which are abundantly equipped with sensitive cells that perceive odors. Substances dissolved in water, entering the nostrils, irritate these cells, transmitting a signal to the brain about a particular smell.
Water circulates freely through the cavities of the nostrils thanks to special valves located in them.
At the same time, the sense of smell in different species of fish is developed differently. However, smell is usually much more important for fish than vision.

Available in fish and taste buds.
Fish perfectly distinguishes bitter from sweet or salty. The taste perceptions of fish are different from the olfactory lobes of the brain! Fish taste buds, which are sensitive cells, are located in the mouth, on the lips, cheeks, mustache, as well as on the sides and head.

A characteristic and very important sensory organ for fish is lateral line(also found in aquatic amphibians).
The lateral line is a kind of sensor for movements and vibrations of water. With its help, for example, predators perfectly sense the slightest movements of a potential victim, and the victim, on the contrary, senses a hidden predator. And also thanks to this “sensor”, fish navigate in the underwater space, avoid stationary obstacles, determine the location of food, the direction of the current, etc.

The lateral line is a channel passing through the entire body and communicating with water through holes in the scales. It contains very sensitive cells that respond to atmospheric pressure and inform the brain about its changes.
This sensitive channel is also called the seismosensory organ.
Sensitive organs that respond to pressure fluctuations in water are also found on the head, jaws and gill covers of fish. The lateral line is connected by the vagus nerve.

The lateral line can be complete: it runs along the entire body of the fish; incomplete, and it may also be absent (for example, in herring). However, fish that lack a lateral line have other, well-developed channels of nerve endings. Damage to the lateral line of a fish can very quickly cause its death.

Hearing. Fish hear well in water, and their hearing, along with vision, is the most important sense that helps them navigate their environment. The hearing organs of fish are different from similar organs of terrestrial animals and are of two types: without connection and with connection with the swim bladder, which acts as a resonator and sound transducer. A fish taken out of the water stops hearing. The lateral line of fish also picks up sound vibrations of low frequencies. The hearing organs of fish are capable of perceiving only vibrations propagated in water with a frequency of 5 to 15 thousand per second. Fish hear low-frequency sounds better, distinguish tones, and have the ability to navigate where the sound source is, but only at short distances.

Since most fish are suspicious of noise, and many are frightened by it, while in a boat, the angler must eliminate knocking and creaking in the rowlocks, do not knock the oars on the hull of the vessel, carefully lower them into the water, carefully move from place to place, quietly set anchors On the shore, the fisherman must walk carefully and quietly, do not drive stakes into the ground, or throw objects onto it, since all this is well transmitted by vibrations of the soil into the water. When casting sinkers, you need to avoid loud splashes, do not hit the water with the rod, generally try to throw gear less often, and also not make noise when fishing for a large specimen, lower the cage with the prey to such a depth that the fish does not fight.

Despite the fact that only one tenth of one percent of sound vibrations penetrates from air into water, you should speak quietly. If you do this loudly, you can again cause vibrations in the soil, which will be transmitted to the water.

Lateral line organs. This is what scientists call the feeling kidneys of fish, which are sensitive cells with hairs located in a gelatinous protrusion that sways easily under the influence of water currents. In most bony fishes, the sensory buds are located in closed canals and form a lateral line that can extend onto the head. The canals are filled with mucus, into which the gelatinous protrusions of the kidneys protrude. The channels are connected to the external environment by small holes in the scales.

With the help of this sensory organ, fish determine the direction, strength of current and waves, and the size of objects moving in the water. When visibility is poor, the lateral line replaces the fish's vision.

Smell and taste. The organs of smell in fish are the nostrils located on both sides of the head. By passing water in which certain substances are dissolved through the nostrils, the fish catches their odors. The sense of smell helps her search for food and recognize enemies. It is believed that salmon use their scent to find spawning grounds in the rivers where they hatched.

Taste buds of fish are located in the mouth, on the antennae, gills, head, fin rays and on the surface of the body. Fish perceive different shades of taste: sweet, bitter, salty, sour.

Touch. Not all fish have organs of touch. They are mainly the antennae at the end of the lips. Some fish have only one antennae, others have pairs. Antennae help fish search for food at the bottom.

The fish's senses include: vision, hearing, lateral line, electroreception, smell, taste and touch. Let's look at each one separately.

Organ of vision

Vision- one of the main sense organs in fish. The eye consists of a round shaped lens that has a hard structure. It is located near the cornea and allows you to see at a distance of up to 5 m at rest, maximum vision reaches 10-14 m.

The lens captures many light rays, allowing you to see in several directions. Often the eye has an elevated position, so it receives direct rays of light, oblique, as well as from above, below, and from the sides. This significantly expands the fish’s field of vision: in the vertical plane up to 150°, and in the horizontal plane up to 170°.

Monocular vision– the right and left eyes receive a separate image. The eye consists of three membranes: the sclera (protects from mechanical damage), the vascular (supplies nutrients), and the retinal (provides light perception and color perception due to the system of rods and cones).

Hearing organ

Hearing aid(inner ear or labyrinth) located in the back of the skull, includes two compartments: upper oval and round lower pouches. The oval sac contains three semicircular canals - this is an organ of balance; endolymph flows inside the labyrinth; in cartilaginous fish it connects with the environment through the excretory duct; in bony fish it ends blindly.

The organ of hearing in fish is combined with the organ of balance.

The inner ear is divided into three chambers, each containing the otolith (part of the vestibular apparatus that responds to mechanical stimulation). The auditory nerve ends inside the ear, forming hair cells (receptors); when the position of the body changes, they are irritated by the endolymph of the semicircular canals and help maintain balance.

The perception of sounds is carried out due to the lower part of the labyrinth - a round sac. Fish are able to detect sounds in the range of 5Hz – 15kHz. The hearing aid includes the lateral line (allows you to hear low-frequency sounds) and the swim bladder (acts as a resonator, connected to the inner ear through Weberian apparatus, consisting of 4 bones).

Pisces are myopic animals, often move in muddy water, with poor lighting; some individuals live in the depths of the sea, where there is no light at all. What sense organs and how do they allow one to navigate in water under such conditions?

Side line

First of all, this lateral line- the main sensory organ in fish. It is a channel that runs under the skin along the entire body and branches in the head area, forming a complex network. It has holes through which it communicates with the environment. Inside there are sensitive kidneys (receptor cells) that perceive the slightest changes around.

This way they can determine the direction of the current, navigate the area at night, and sense the movement of other fish, both in a school and of predators approaching them. The lateral line is equipped with mechanoreceptors; they help aquatic inhabitants to dodge pitfalls and foreign objects, even in poor visibility.

The lateral line can be complete (located from the head to the tail), incomplete, or can be completely replaced by other developed nerve endings. If the lateral line is injured, the fish will no longer be able to survive for long, which indicates the importance of this organ.

The lateral line of fish is the main organ of orientation

Electroreception

Electroreception– a sensory organ of cartilaginous fish and some bony fish (electric catfish). Sharks and rays sense electric fields using ampullae of Lorenzini - small capsules filled with mucous contents and lined with specific sensitive cells, located in the head area and communicate with the surface of the skin using a thin tube.

Very susceptible and capable of sensing weak electric fields (the reaction occurs at a voltage of 0.001 mKV/m).

Thus, electrosensitive fish can track down prey hidden in the sand thanks to the electric fields that are created when muscle fibers contract during breathing.

Lateral line and electrosensitivity– these sense organs are characteristic only of fish!

Olfactory organ

Smell carried out using cilia located on the surface of special bags. When the fish smells the smell, the sacs begin to move: they contract and expand, capturing odorous substances. The nose includes 4 nostrils, sent out by many sensory cells.

With their sense of smell they easily find food, relatives, and a partner for the spawning period. Some individuals are able to signal danger by releasing substances to which other fish are sensitive. It is believed that the sense of smell for aquatic inhabitants is more important than vision.

Organs of taste

Taste buds fish are concentrated in the oral cavity (oral buds) and oropharynx. In some species (catfish, burbot) they are found in the area of ​​the lips and whiskers, in carp - throughout the body.

Fish are able to recognize, like humans, all taste characteristics: salty, sweet, sour, bitter. With the help of sensitive receptors, fish can find the necessary food.

Touch

Touch receptors located in cartilaginous fish in areas of the body not covered with scales (the abdominal region in stingrays). In teleosts, sensitive cells are scattered throughout the body, the bulk are concentrated on the fins and lips - they make it possible to sense touch.

Features of sensory organs in bony and cartilaginous

Inert fish have a swim bladder, which perceives a wider range of sounds; cartilaginous fish do not have it, and they also do not have a complete division of the inner ear into oval and round sacs.

Color vision is characteristic of teleosts, since their retina contains both rods and cones. The cartilaginous visual sensory organ includes only rods that are not capable of distinguishing colors.

Sharks have a very keen sense of smell; the anterior part of the brain (provides the sense of smell) is much more developed than other representatives.

Electrical organs are special organs of cartilaginous fish (rays). They are used for protection and attack on the victim, and discharges with a power of up to 600V are generated. They can act as a sensory organ - by forming an electric field, stingrays detect changes when foreign bodies enter it.

MINISTRY OF EDUCATION AND SCIENCE OF THE RUSSIAN FEDERATION FAR EASTERN STATE UNIVERSITY

INSTITUTE OF CHEMISTRY AND APPLIED ECOLOGY

CHEMICAL FACULTY

DEPARTMENT OF BIOORGANIC CHEMISTRY AND BIOTECHNOLOGY

The sense of smell in the life of fish

Abstract of a student of group 014

Volodko Alexandra Viktorovna

Vladivostok

Introduction

Smell and olfactory thresholds

Olfactory organ

Influence and action of chemical signals

Conclusion

Bibliography

Introduction

Do fish smell? Of course they do. Moreover, as it became known, fish of different species have different sensitivity to olfactory and gustatory stimuli. Unlike people, who are endowed with the ability to distinguish taste and smell, fish perceive chemical stimuli using three completely independent sensitive (chemosensory) systems - taste, smell and general chemical taste, of which the olfactory analyzer plays the most important role. With the help of the olfactory organ, fish try to localize the smell and approach its source.

Fish acquired the ability to distinguish between chemical stimuli a very long time ago - according to paleontologists - at least 500 million years ago. It is believed that the ability to distinguish between various chemical substances is the most ancient way of obtaining information about the environment.

Through the sense of smell, fish receive information about changes in the external environment, distinguish food, find their school, partners during spawning, detect predators, and calculate prey. On the skin of some species of fish there are cells that, when the skin is wounded, release a “fear substance” into the water, which is a signal of danger to other fish. Pisces actively use chemical information to give alarm signals, warn of danger, and attract individuals of the opposite sex. This organ is especially important for fish living in turbid water, where, along with tactile and sound information, fish actively use olfactory information.

The sense of smell has a great influence on the functioning of many organs and systems of the body, toning or inhibiting them. There are known groups of substances that have a positive (attractant) or negative (repellent) effect on fish. Attractants are widely used by fishermen in the preparation of baits and baits. The sense of smell is closely related to other senses: taste, vision and balance. At different times of the year, the olfactory sensations of fish are not the same; they become more acute in spring and summer, especially in warm weather.

Smell and olfactory thresholds

Smell is a sensation that occurs when volatile substances (those that produce quite a lot of molecules in the gas phase) enter specialized olfactory cells when inhaled. According to many scientists, animals are guided by a mixture of basic odors: musky, camphor, mint, ethereal, floral, pungent and rotten. These odors make up all the odors found in nature. But what is smell from a chemical point of view - what substances smell? They are only 10% of the known 10 million organic substances.

For a very long time, chemists tried to find a relationship between the structure of a chemical substance and its smell. The results are not brilliant. It is known that if the molecular weight of a substance is more than 400, then it does not smell, because it simply does not produce vapor in the required quantities. But which of the remaining ones smell is quite difficult to say. And with vapors in the required quantities, there is also no clear answer - it is not possible to predict the olfactory thresholds (that is, the minimum dose at which an odor is felt) of substances based on their chemical structure. By the way, it turned out that these same olfactory thresholds are very different.

Fish have a very high sensitivity to odors (they can sense a dilution of bloodworm extract in a ratio of one to a billion; higher concentrations are less attractive to them). Threshold concentrations of substances that cause noticeable electrophysiological responses in the olfactory system can be extremely low - up to 10 -9 -10 -13 g. Behavioral responses are recorded at concentrations of 10 -6 -10 -9 g. However, all these threshold concentrations have been measured for artificial chemicals. Most likely, the thresholds of sensitivity to natural odors are even lower.

The problem in this area of ​​science is that noses are much more sensitive than instruments. Chromatographs and mass spectrometers typically work down to 10-9 g (nanograms). Therefore, when researchers analyze odors using physical and chemical methods and try to identify substances that convey some information, it is not always possible to obtain an answer to the question posed. Therefore, some observations of the reaction of fish to a particular smell remain only observations.

Olfactory organ

How do fish perceive odor signals and how sensitive are they to a variety of odors? In most fish, the olfactory organ is well developed and is located on the upper surface of the head in front of the eyes. But in evolutionarily ancient cartilaginous fish, and among bony fish, in lungfishes, the olfactory organs are located on the lower part of the head.

Usually there are two olfactory openings, and they are quite clearly visible on the head of the fish. Sticklebacks, garfish, pomacentrids and some others have one olfactory opening. And, for example, the pufferfish has no nostrils at all, and the olfactory organ is placed inside a tentacle-like outgrowth protruding above the surface of the head.

If there are two olfactory openings, water is sucked in through one of them, and through the other it is thrown out. The water drawn in enters the nasal or olfactory cavity (nasal sac), at the bottom of which there are olfactory folds that make up the olfactory rosette. The surface of the folds is covered with olfactory epithelium. Some fish have so-called additional ventilation olfactory sacs in their olfactory organ. They are intended for ventilation of the nasal cavity and for the production of olfactory mucus. Thanks to them, through a specially developing hole, a connection can arise between the organ of smell and the oral cavity. There are no receptor cells in such bags.

The composition of the olfactory epithelium on the olfactory folds includes basal, supporting, mucous and, finally, the actual nerve, receptor cells. They have a thick process - a dendrite, extending from the central part. The dendrite ends in a “club” that protrudes from the surface of the epithelium. Here, special receptor proteins are built into the cell membrane. As a result of their interaction with molecules of odorant substances entering the olfactory organ, the operation of ion channels changes and a receptor potential is generated. In the form of an electrical impulse, it arrives along the axons of receptor cells to the primary olfactory center - the olfactory bulbs located between the olfactory organ and the forebrain, usually right next to the latter. The forebrain itself in fish is a secondary olfactory center in which final processing of information occurs.

Among all the studied fish, the common catfish is the leader in the number of chemosensitive cells - it has approximately 160 million chemoreceptors - that is, slightly less than in a dog. Bream has up to 27 million such cells, burbot has up to 11 million, pike has up to six million, river perch has up to 3 million, and minnow has 900 thousand.

As for the additional olfactory (vomeronasal) system, fish do not have it as a formalized structure; they appear only in evolutionarily more advanced organisms, starting with amphibians.

As already mentioned, different fish are differently sensitive to different odors, so-called olfactory stimuli - the more receptor (sensitive) cells there are in the olfactory organ, the more sensitive the fish. In accordance with the breadth of the spectrum of perceived odors and the level of sensitivity to these odors, fish are divided into two groups: macrosmatics, responding to a wide range of odor stimuli and exhibiting a high level of olfactory sensitivity to them, and microsmatics, reacting only to a limited set of odors.

The olfactory system of fish is characterized by slow adaptation (decreased sensitivity to the current odor stimulus). Thanks to this, habituation does not occur, and odor stimuli retain their signaling value for a long time. This is extremely important so that fish can navigate by the source of the smell and move towards it. This happens during migrations, in particular during salmon migrations. When approaching the mouths of spawning rivers, these fish begin to adhere to certain layers of water, periodically making short-term trips beyond their limits.

In this way, they manage to control their position in space and not lose the area with the maximum concentration of odor - the so-called odor corridor. Already in rivers, at the confluence of large tributaries, salmon begin to move in a zigzag manner in order to stick to those areas that carry the smell of their native spawning ground. This phenomenon of returning to native areas is called homing. It is based on the phenomenon of imprinting odor signals of native habitats in memory. It is assumed that this smell is formed due to substances entering the water from adjacent land areas. It is interesting that fish remember the smell (or perhaps the nature of its change) not only of the area in the upper reaches where their growth and development took place, but also of the entire path from it to the mouth of the river. If salmon have their olfactory sacs closed, they lose the ability to determine which tributary to ascend.

VISION

The organ of vision - the eye - in its structure resembles a photographic apparatus, and the lens of the eye is similar to a lens, and the retina is similar to the film on which the image is obtained. In terrestrial animals, the lens is lenticular in shape and is capable of changing its curvature, so animals can adapt their vision to distance. The lens of fish is spherical and cannot change shape. Their vision is adjusted to different distances as the lens approaches or moves away from the retina.

The optical properties of the aquatic environment do not allow the fish to see far. Almost the limit of visibility for fish in clear water is considered to be a distance of 10-12 m, and fish can see clearly no further than 1.5 m. Diurnal predatory fish living in clear water (trout, grayling, asp, pike) see better. Some fish see in the dark (pike perch, bream, catfish, eel, burbot). They have special light-sensitive elements in their retina that can perceive weak light rays.

The angle of view of fish is very large. Without turning their bodies, most fish are able to see objects with each eye in a zone of about 150° vertically and up to 170° horizontally.

Otherwise, the fish sees objects above the water. In this case, the laws of refraction of light rays come into force, and the fish can see without distortion only objects that are directly overhead - at the zenith. Obliquely incident light rays are refracted and compressed into an angle of 97°.6 (Fig. 2). The sharper the angle of entry of the light beam into the water and the lower the object, the more distorted the fish sees it. When the light beam falls at an angle of 5-10°, especially if the water surface is choppy, the fish stops seeing the object.

The rays coming from the eye of the fish outside the cone are completely reflected from the water surface, so it appears to the fish as mirror-like.

On the other hand, the refraction of rays allows the fish to see seemingly hidden objects. Let's imagine a body of water with a steep, steep bank. Outside the refraction of rays, a person can see a person on the water surface.

Pisces distinguish colors and even shades.

Color vision in fish is confirmed by their ability to change color depending on the color of the ground (mimicry). It is known that perch, roach, and pike, which stay on a light sandy bottom, have a light color, and on a black peat bottom they are darker. Mimicry is especially pronounced in various flounders, capable of adapting their color to the color of the ground with amazing accuracy. If a flounder is placed in a glass aquarium with a chessboard placed under the bottom, then chess-like cells will appear on its back. Under natural conditions, a flounder lying on a pebble bottom blends so well with it that it becomes completely invisible to the human eye. At the same time, blinded fish, including flounder, do not change their color and remain dark-colored. From this it is clear that the change in color by fish is associated with their visual perception.

Experiments of feeding fish from multi-colored cups confirmed that fish clearly perceive all spectral colors and can distinguish similar shades. The latest experiments based on spectrophotometric methods have shown that many species of fish perceive individual shades no worse than humans.

Using food training methods, it has been established that fish also perceive the shape of objects - they distinguish a triangle from a square, a cube from a pyramid.

Of particular interest is the attitude of fish to artificial light. Even in pre-revolutionary literature they wrote that a fire built on the river bank attracts roaches, burbot, catfish and improves fishing results. Recent studies have shown that many fish - sprat, mullet, syrty, saury - are directed to sources of underwater lighting, so electric light is currently used in commercial fishing. In particular, this method is used to successfully catch sprat in the Caspian Sea, and saury near the Kuril Islands.

Attempts to use electric light in sport fishing have not yet yielded positive results. Such experiments were carried out in winter in places where perch and roach accumulated. They cut a hole in the ice and lowered an electric lamp with a reflector to the bottom of the reservoir. Then they fished with a jig and added bloodworms in a neighboring hole and in a hole cut away from the light source. It turned out that the number of bites near the lamp is less than away from it. Similar experiments were carried out when catching pike perch and burbot at night; they also did not have a positive effect.

For sport fishing, it is tempting to use baits coated with luminous compounds. It has been established that fish grab luminous baits. However, the experience of Leningrad fishermen did not show their advantages; In all cases, fish take regular bait more readily. The literature on this issue is also not convincing. It describes only cases of catching fish with luminous baits, and does not provide comparative data on fishing under the same conditions with ordinary baits.

The visual characteristics of fish allow us to draw some conclusions that are useful for the fisherman. It is safe to say that a fish located at the surface of the water is not able to see a fisherman standing on the shore further than 8-10 m and sitting or wading - further than 5-6 m; The transparency of the water also matters. In practice, we can assume that if an angler does not see a fish in the water when he looks at a well-lit water surface at an angle close to 90°, then the fish does not see the angler. Therefore, camouflage makes sense only when fishing in shallow places or on top in clear water and when casting over a short distance. On the contrary, items of fishing equipment that are close to the fish (lead, sinker, net, float, boat) should blend into the surrounding background.

HEARING

The presence of hearing in fish was denied for a long time. Facts such as fish approaching the feeding place when called, attracting catfish by hitting the water with a special wooden mallet (“knocking” catfish), and reacting to the whistle of a steamboat have not yet proved much. The occurrence of the reaction could be explained by irritation of other sense organs. Recent experiments have shown that fish respond to sound stimuli, and these stimuli are perceived by the auditory labyrinths in the fish’s head, the surface of the skin, and the swim bladder, which plays the role of a resonator.

The sensitivity of sound perception in fish has not been established exactly, but it has been proven that they pick up sounds worse than humans, and fish hear high tones better than low ones. Fish hear sounds arising in the aquatic environment at a considerable distance, but sounds arising in the air are poorly heard, since sound waves are reflected from the surface and do not penetrate well into the water. Given these features, the angler should be wary of making noise in the water, but does not have to worry about spooking the fish by talking loudly. The use of sounds in sport fishing is interesting. However, the question of which sounds attract fish and which repels them has not been studied. So far, sound is used only when catching catfish, by “closing.”

Lateral line organ

The lateral line organ is present only in fish and amphibians that constantly live in water. The lateral line is most often a canal that stretches along the body from head to tail. Nerve endings branch out in the canal, perceiving even the most insignificant water vibrations with great sensitivity. With the help of this organ, fish determine the direction and strength of the current, feel the currents of water formed when underwater objects are washed away, feel the movement of a neighbor in the school, enemies or prey, and disturbances on the surface of the water. In addition, the fish also perceives vibrations that are transmitted to the water from the outside - soil shaking, impacts on the boat, blast waves, vibration of the ship's hull, etc.

The role of the lateral line in the fish's grasping of prey has been studied in detail. Repeated experiments have shown that a blinded pike is well oriented and accurately grabs a moving fish, not paying attention to a stationary one. A blind pike with a destroyed lateral line loses the ability to orient itself, bumps into the walls of the pool and... being hungry, she does not pay attention to the swimming fish.

With this in mind, anglers must be careful both on the shore and in the boat. Shaking the soil under your feet, a wave from careless movement in the boat can alert the fish and scare it away for a long time. The nature of the movement of artificial baits in the water is not indifferent to the success of fishing, since predators, when pursuing and seizing prey, feel the water vibrations created by it. Of course, those baits that most fully reproduce the characteristics of the usual prey of predators will be more catchy.

Organs of smell and taste

The organs of smell and taste in fish are separated. The organ of smell in bony fishes is paired nostrils, located on both sides of the head and leading into the nasal cavity, lined with olfactory epithelium. Water enters one hole and leaves the other. This arrangement of the olfactory organs allows the fish to sense the odors of substances dissolved or suspended in water, and during the current the fish can only smell the stream carrying the odorous substance, and in calm waters - only in the presence of water currents.

The olfactory organ is least developed in diurnal predatory fish (pike, asp, perch), and stronger in nocturnal and crepuscular fish (eel, catfish, carp, tench).

The taste organs are located mainly in the mouth and pharyngeal cavity; In some fish, taste buds are located in the area of ​​the lips and whiskers (catfish, burbot), and sometimes located throughout the body (carp). As experiments show, fish are able to distinguish between sweet, sour, bitter and salty. Just like the sense of smell, the sense of taste is more developed in nocturnal fish.