- Read: Variety of fish: shape, size, color
Organ of balance and hearing
- Read more: Sense organs of fish
Cyclostomes and fish have a paired organ of balance and hearing, which is represented by the inner ear (or membranous labyrinth) and located in the auditory capsules of the back of the skull. The membranous labyrinth consists of two sacs: 1) the superior oval; 2) the bottom is round.
In cartilaginous animals, the labyrinth is not completely divided into oval and round sacs. In many species, an outgrowth (lagena) extends from the round sac, which is the rudiment of the cochlea. Three semicircular canals extend from the oval sac in mutually perpendicular planes (in lampreys - 2, in hagfishes - 1). At one end of the semicircular canals there is an extension (ampulla). The cavity of the labyrinth is filled with endolymph. An endolymphatic duct departs from the labyrinth, which in bony fishes ends blindly, and in cartilaginous fishes it communicates with the external environment. The inner ear has hair cells, which are the endings of the auditory nerve and are located in patches in the ampullae of the semicircular canals, sacs and lagena. The membranous labyrinth contains auditory pebbles, or otoliths. They are located in three on each side: one, the largest, otolith, is in a round sac, the second is in an oval sac, and the third is in the lagena. The annual rings are clearly visible on the otoliths, which are used to determine the age of some fish species (smelt, ruffe, etc.).
The upper part of the membranous labyrinth (oval sac with semicircular canals) serves as an organ of balance, Bottom part labyrinth perceives sounds. Any change in head position causes movement of the endolymph and otoliths and irritates the hair cells.
Fish perceive sounds in water in the range from 5 Hz to 15 kHz; sounds of higher frequencies (ultrasounds) are not perceived by fish. Fish also perceive sounds using the sensory organs of the lateral line system. Sensitive cells of the inner ear and lateral line have a similar structure, are innervated by branches of the auditory nerve and belong to a single acousticolateral system (center in the medulla oblongata). The lateral line expands the wave range and allows you to perceive low-frequency sound vibrations (5-20 Hz) caused by earthquakes, waves, etc.
The sensitivity of the inner ear increases in fish with a swim bladder, which is a resonator and reflector of sound vibrations. The connection of the swim bladder with the inner ear is carried out using the Weberian apparatus (4 ossicle system) (in cyprinids), blind outgrowths of the swim bladder (in herring, cod) or special air cavities. The most sensitive to sounds are fish that have a Weber apparatus. With the help of a swim bladder connected to the inner ear, fish are able to perceive sounds of low and high frequencies.
N.V. ILMAST. INTRODUCTION TO ICHTHYOLOGY. Petrozavodsk, 2005
What kind of hearing do fish have? and How does the hearing organ work in fish?
While fishing, the fish may not see us, but its hearing is excellent, and it will hear the slightest sound that we make. Hearing organs in fish: inner ear and lateral line.
Water is good guide sound vibrations, and a clumsy fisherman can easily spook the fish. For example, a clap when closing a car door, through aquatic environment extends over many hundreds of meters. Having made quite a splash, there is no reason to be surprised why the bite is weak, and maybe even absent altogether. Be especially careful big fish, which accordingly is the main purpose of fishing.
Freshwater fish can be divided into two groups:
. Pisces with excellent hearing(carp, roach, tench)
. Pisces who have average hearing
(pike, perch)
How do fish hear?
Excellent hearing is achieved due to the fact that the inner ear is connected to the swim bladder. In this case, external vibrations are amplified by the bubble, which plays the role of a resonator. And from him they come to inner ear.
The average person hears a range of sounds from 20 Hz to 20 kHz. And fish, for example carp, with the help of their hearing organs, are able to hear sound from 5 Hz to 2 kHz. That is, fish’s hearing is better tuned to low vibrations, but high vibrations are perceived worse. Any careless step on the shore, a blow, a rustle, is perfectly heard by carp or roach.
In predatory freshwater fish, the hearing organs are built differently; in such fish there is no connection between the inner ear and the swim bladder.
Fish such as pike, perch, and pike perch rely more on vision than hearing, and do not hear sound above 500 hertz.
Even the noise of boat engines greatly affects the behavior of fish. Especially those who have excellent hearing. Excessive noise can cause fish to stop feeding and even interrupt spawning. We fish already have a good memory, and they remember sounds well and associate them with events.
The study showed that when the carp stopped feeding due to noise, the pike continued to hunt without paying any attention to what is happening.
Hearing organs in fish
Behind the skull of the fish there are a pair of ears, which, like the inner ear in humans, in addition to the function of hearing, are also responsible for balance. But unlike us, fish have an ear that does not have an outlet.
The lateral line picks up low frequency sound and water movement near the fish. Fatty sensors located under the lateral line clearly transmit the external vibration of water to the neurons, and then the information goes to the brain.
Having two lateral lines and two inner ears, the organ of hearing in fish perfectly determines the direction of sound. A slight delay in the readings of these organs is processed by the brain, and it determines from which side the vibration is coming.
Of course, on modern rivers, lakes and stakes there is enough noise. And over time, the fish’s hearing gets used to many noises. But regularly repeated sounds, even if it is the noise of a train, are one thing, and unfamiliar vibrations are another thing. So for normal fishing it will be necessary to maintain silence and understand how hearing works in fish.
The saying "dumb as a fish" scientific point vision has long lost its relevance. It has been proven that fish can not only make sounds themselves, but also hear them. For a long time there has been debate over whether fish hear. Now the answer of scientists is known and unambiguous - fish not only have the ability to hear and have the appropriate organs for this, but they themselves can also communicate with each other through sounds.
A little theory about the essence of sound
Physicists have long established that sound is nothing more than a chain of regularly repeating compression waves of a medium (air, liquid, solid). In other words, sounds in water are just as natural as on its surface. In water sound waves, the speed of which is determined by the compression force, can propagate at different frequencies:
- most fish perceive sound frequencies in the range of 50-3000 Hz,
- vibrations and infrasound, which refer to low-frequency vibrations up to 16 Hz, are not perceived by all fish,
- are fish capable of perceiving ultrasonic waves whose frequency exceeds 20,000 Hz) - this question has not yet been fully studied, therefore, convincing evidence regarding the presence of such an ability in underwater inhabitants has not been obtained.
It is known that sound travels four times faster in water than in air or other gaseous media. This is the reason that fish receive sounds that enter the water from the outside in a distorted form. Compared to land dwellers, fish's hearing is not as acute. However, experiments by zoologists have revealed very Interesting Facts: in particular, some types of slaves can distinguish even halftones.
More about the sideline
Scientists consider this organ in fish to be one of the most ancient sensory formations. It can be considered universal, since it performs not one, but several functions at once, ensuring the normal functioning of fish.
The morphology of the lateral system is not the same in all fish species. There are options:
- The very location of the lateral line on the body of the fish may refer to a specific feature of the species,
- In addition, there are known species of fish with two or more lateral lines on both sides,
- In bony fish, the lateral line usually runs along the body. For some it is continuous, for others it is intermittent and looks like a dotted line,
- In some species, the lateral line canals are hidden inside the skin or run open along the surface.
In all other respects, the structure of this sensory organ in fish is identical and it functions in the same way in all types of fish.
This organ reacts not only to the compression of water, but also to other stimuli: electromagnetic, chemical. Main role Neuromasts, consisting of so-called hair cells, play a role in this. The very structure of the neuromasts is a capsule (mucous part), into which the actual hairs of the sensitive cells are immersed. Since the neuromasts themselves are closed, with external environment they are connected through microholes in the scales. As we know, neuromasts can also be open. These are characteristic of those species of fish in which the lateral line canals extend onto the head.
In the course of numerous experiments conducted by ichthyologists in different countries it was established for certain that the lateral line perceives low-frequency vibrations, not only sound waves, but waves from the movement of other fish.
How hearing organs warn fish of danger
In the wild, as well as in a home aquarium, fish take adequate measures when they hear the most distant sounds of danger. While the storm in this area of the sea or ocean is still just beginning, the fish change their behavior ahead of time - some species sink to the bottom, where wave fluctuations are the smallest; others migrate to quiet locations.
Uncharacteristic fluctuations in water are regarded by the inhabitants of the seas as an approaching danger and they cannot help but react to it, since the instinct of self-preservation is characteristic of all life on our planet.
In rivers, the behavioral reactions of fish may be different. In particular, at the slightest disturbance in the water (from a boat, for example), the fish stop eating. This saves her from the risk of being hooked by a fisherman.
The first attempts to find an organ that perceives sounds relate to end of the 19th century V. Thus, Kreidl (1895), destroying the labyrinth of fish, where, in his opinion, the hearing organ could be located, (comes to the conclusion that fish do not have a hearing organ. Repeating his experiments and cutting the nerves of the skin, lateral line and labyrinth , Bigelow (1904) showed that only transection of the nerve innervating the labyrinth leads to hearing loss.He suggested that the perception of sound is carried out bottom labyrinth (Sacculus and lagenae). Piper (Piper, 1906) electrophysiologically, diverting action currents from the VIII nerve various types fish when stimulated by sound, came to the conclusion that “the perception of sounds by fish is carried out using a labyrinth.
Anatomical studies of the fish ear led De Burlet (1929) to the conclusion that the hearing organ of fish is the Sacculus labyrinth.
Parker (1909) based on experiments with Mustelus cards also concluded that the hearing of fish is associated with the labyrinth, which, in addition to the auditory function, is related to maintaining balance and muscle tone. However, the most complete data on the function of the labyrinth were obtained only after the work of Frisch and Stetter (Frisch a. Stetter, 1932).
In minnows with developed food reflexes to sound, individual parts of the maze were removed in a chronic experiment, after which the presence of a reaction was again checked. Experiments have shown that the auditory function is carried out by the lower part of the labyrinth Sacculus and lagenae, while the Utriculus and semicircular canals are involved in “maintaining balance. In 1936 and 1938 Frisch undertook even more detailed studies of the localization of the inner ear of fish, studying in minnows the importance of Sacculus and lagenae, their otoliths and sensitive epithelium in the perception of sound.
The fish auditory receptor is connected to the auditory center located in medulla oblongata, using the VIII pair of head nerves.
In Fig. Figure 35 shows a labyrinth with the auditory organ of fish. Noting the diverse structure of hearing aids in fish, Frisch notes two main types: apparatuses that are not connected to the swim bladder, and apparatuses that integral part which is the swim bladder (Fig. 36). The connection of the swim bladder with the inner ear is carried out using the Weberian apparatus - four pairs of movably articulated bones connecting the labyrinth with the swim bladder. Frisch showed that fish with hearing aid‘The second type (Surrinidae, Siluridae, Characinidae, Gymnotidae) have more developed hearing.
Thus, the receptor that perceives sound is the Sacculus and lagenae, and the swim bladder has the role of a resonator, amplifying and selecting sound frequencies in a certain way.
Subsequent works by Diesselhorst (1938) and Dijkgraaf (1950) indicate that in fish of other families, Utriculus can also take part in the perception of sound.
“Don’t make any noise to me here, otherwise you’ll scare away all the fish” - how many times have we heard a similar phrase. And many novice fishermen still naively believe that such words are spoken solely out of severity, a desire to remain silent, and superstition. They think something like this: a fish swims in water, what can it hear there? It turns out that there is a lot; there is no need to be mistaken about this. To clarify the situation, we want to tell you what kind of hearing fish have and why they can easily be scared away by some sharp or loud sounds.
Those who think that carp, bream, carp and other inhabitants of water areas are practically deaf are deeply mistaken. Fish have excellent hearing - both due to developed organs (the inner ear and lateral line), and due to the fact that water conducts sound vibrations well. So it’s really not worth making noise during feeder fishing. But how well does a fish hear? Just like us, better or worse? Let's look at this issue.
How well does a fish hear?
Let's take our beloved carp as an example: it hears sounds in the range 5 Hz - 2 kHz. These are low vibrations. For comparison: we humans, when we are not yet old, hear sounds in the range of 20 Hz - 20 kHz. Our threshold of perception begins at higher frequencies.
So, in a sense, fish hear even better than us, but to a certain limit. For example, they perfectly capture rustles, impacts, and pops, so it is important not to make noise.
According to hearing, fish can be divided into 2 groups:
hear perfectly - these are cautious carp, tench, roach
hear well - these are bolder perches and pikes
As you can see, there are no deaf people. So slamming a car door, turning on music, or talking loudly with neighbors near the fishing spot is strictly contraindicated. This and similar noise can nullify even a good bite.
What hearing organs do fish have?
At the back of the fish's head is located pair of inner ears, responsible for hearing and sense of balance. Please note that these organs have no exit to the outside.
Along the body of the fish, on both sides, pass lateral lines- unique detectors of water movement and low-frequency sounds. Such vibrations are recorded by fat sensors.
How do fish's hearing organs work?
The fish determines the direction of sound with its lateral lines, and the frequency with its inner ears. After which it transmits all these external vibrations using fatty sensors located under the lateral lines - along neurons to the brain. As you can see, the work of the hearing organs is organized ridiculously simply.
In this case, the inner ear of non-predatory fish is connected to a kind of resonator - to the swim bladder. He is the first to receive all external vibrations and strengthens them. And these increased power sounds come to the inner ear, and from it to the brain. Due to this resonator, carp fish hear vibrations with a frequency of up to 2 kHz.
But in predatory fish, the inner ears are not connected to the swim bladder. Therefore, pike, pike perch, and perch hear sounds up to approximately 500 Hz. However, even this frequency is enough for them, especially since their vision is better developed than that of non-predatory fish.
In conclusion, we would like to say that the inhabitants of the water area get used to constantly repeating sounds. So even the noise of a boat engine, in principle, may not scare the fish if they often swim in the pond. Another thing is unfamiliar, new sounds, especially sharp, loud, and prolonged ones. Because of them, the fish may even stop feeding, even if you were able to pick up good bait, or spawn, and as practice shows, the sharper its hearing, the sooner and sooner this will happen.
There is only one conclusion, and it is simple: don’t make noise when fishing, which we have already written about several times in this article. If you do not neglect this rule and maintain silence, the chances of a good bite will remain maximum.
