Swimming bubble in fish is used in quality. Description of the swimming air bubble of fish. Development and structure of the hydrostatic organ

The stories about the swimming bubble speech was mainly about its position on the intestine in different groups of fish, as well as on the paths of possible evolution from the primary ventral light ancient fish to the truly donasal swimming bubble of fish of modern. Today we will consider in more detail the inner structure of this body and let us return to the diversity of its structure.

Previously, we noted that in the evolution of fish from the ancestors (often primitive) to modern, more difficult to organized forms there is a tendency, firstly, to the loss of the connection of the swimming bubble with the intestine and, secondly, to the overall complication of its structure. Indeed, the youngest taxa are, as a rule, closed, while the older (having an earlier evolutionary origin) observes open support.

Fish Swimming Bubble Frame

The transition from openingness to the closed content was carried out in evolution through a gradual refinement and elongation of the air channel and shifting the place of its connection with the digestive tract from the pharynx to the rear intestinal departments. So, in modern open-minded fish, this channel is long and narrow, as, for example, in salmon, and opens behind the stomach, and the Lepisosteus pincers are a representative of one of the ancient groups - it is short and wide, and opens in the esophagus. Such his "front" position shortens the way into a swimming bubble for a swallowed air from the surface of the air and provides a respiratory function.

The principles of the swimming bubble

Initially, let's talk about the principle of the work of the swimming bubble as a hydrostatic organ. This principle is simple: changing the volume of the swimming bubble, the fish changes the overall density of the body, and as a result, it changes and its buoyancy. How is the change in the volume of the swimming bubble? The first researchers thought that this was carried out only due to the surrounding swimming bubble of muscles, the work of which leads to its compression or stretching, which in turn kits air from the bubble or vice versa injected it inside. However, this is not true - the change in the volume of the swimming bubble is exclusively due to the work of the musculature, only a few primitive shallow forms are peculiar. In the overwhelming majority of fish, specialized internal structures are used for this, located in the bubble itself, while musculatura is involved in extreme cases. These structures, depending on the advanced taxon, can be expressed in varying degrees, but at the same time they always distinguish between their two types - the red body and oval. In fact, these are two zones in a swimming bubble shell that perform the synthesis functions (red body) and removal of gases. The functioning of these areas is associated with abundant blood circulation, as the blood is for most fish main, and in the case of closed fish, the only transport "channel" for gases when filling and emptying the swimming bubble.

Now let's take a little more detail the structure of these two "workers" zones.

The structure of the Red Body

Let's start by S. red Body (Lat. Corpus Ruber)which is essentially a gas iron (and in English-language literature it is mainly called this way), which serves for the "injection" of gases from the blood to the cavity of the swimming bubble. It is a accumulation of secretory cells (probably epithelial origin) and capillaries. In different groups of fish, the red body can be expressed irregularly - it can cover either the entire surface of the bubble, or only a small part of it, have a blade structure or is a homogeneous formation, to be lined with multilayer or single-layer epithelium.

The red body looks like a thick accumulation of piggings

Now I will not stop on the details of the work of the entire system, but for further understanding of the structure of the Red Body, it should be noted that the ingress of gases is directly from the blood into the swimming bubble by simply diffusion it is impossible due to the difference of their partial pressures. To overcome this difference, secretory cells are needed, which, due to the chemical reactions occurring in them, provide gas transport in the right direction. For the synthesis of the required volume of gases, secretory cells must be appropriately supplied with blood, which is just the source of these gases. Therefore, the most important component of the Red Body is the accumulation of capillaries that form a thick network in the wall of the swimming bubble and the name of a rather ridiculous and apparent name is not quite scientific name - a wonderful network from the Latin Rete Mirabile. As noted above, in different fish species, the wonderful network, as an integral part of the red body, can be developed to varying degrees, however, if there is, it is built on one universal principle. This principle lies in the very close position of the capillaries, bringing blood to secretory cells and carrying it back. According to these close-up arterial and venous capillaries, there is a parallel (but multidirectional) transport of blood, which provides a complex mechanism for the discharge of partial pressure of gases in the capillaries and the very possibility of "injection" of gases inside the swimming bubble. For more information about this, I will try to tell in a separate post, while I propose just to look at the figure below, which shows the microstructure of the wonderful network and the gas path in different parts.

Microstructure of the wonderful network and the difference in partial pressure of gases in different areas.

The arrows show the direction of gases and blood flow.

Two types of organization of the wonderful network

Speaking about the structure of the wonderful network, it is impossible not to mention that there are two types of organization of parallel bringing and removing capillaries. The wonderful network can be bipolar when two capillar strokes are located sequentially, or unipolar, when there is only one capillar stroke, directly adjacent to secretory cells. These structures are shown in the figure below. Most fish has a wonderful network built by unipolar type, while the eels have bipolarna. Differences in the structure of the wonderful network also manifest themselves in the fact that the number of couples of capillaries (1 bringing + 1 endowing) in the microSeta may vary in different species from units to several thousand.

Unipolar and bipolar types of the wonderful network

The structure of ovala

We now turn to the structure of oval, which is a structure responsible for transporting gases from a swimming bubble in blood. Oval is a portion of the wall of the swimming bubble, richly supplied by vessels, as well as in the case of a red body forming a thick network. The structure of this network, however, is much simpler, since the mechanism of reverse transport of gases from the swimming bubble in blood is much easier. Due to the difference in partial pressures, the gases penetrate the blood on the principle of direct diffusion, therefore no secretory cells and the organization of parallel transport in capillaries are not required to ensure this process. The speed of this diffusion is usually very high and limited, first of all, the speed of blood flow - blood simply does not have time to carry out dissolved gases. In addition, the diffusion process is associated with an area through which it occurs, and the lumen diameter between the resorbing and secretory parts, which, as already mentioned, can be adjusted by the sphincter.

Capillaries oval (shown by the arrow)

Variety of Bony Fish Swimming Bubble Building Bubble

At the end, as I promised, we will return to the variety of the structure of the swimming bubble in different groups of fish. The loss of communication with the intestine, as already mentioned, is not the only trend in the evolution of the swimming bubble. From primitive ancient groups to the most modern young taxa, we see the gradual complication of its structure. This complication is primarily in the emergence of various zones associated with the implementation of certain special functions. The hydrostatic function provides two such zones - these are the above-described red body and oval. Their separation in different fish can be organized in different ways, but in general, it comes down to the separation of the swimming bubble into several cameras. As a rule, there are two such cells - in one, the synthesis of gases occurs, and in another absorption. The variety of buildings and arrangements of cameras relative to each other in bone fish is very large. Some examples are shown in the figure below.

When describing the swimming bubble, it is often separately mentioned by a swimming bubble of giving birth to Anguilla and Conger (Figure D). Indeed, in its structure there are a number of interesting features. Having a connection with the intestines, it, however, functions as a closed-type swimming bubble. What is it manifested? The fact is that the air channel in the eels of these clans is expanded and functionally corresponds to the zone of the oval - through its walls there is resorption of gases into blood, the synthesis of gases is carried out in a single large elongated chamber equipped with a powerful gas iron. In addition, with a swimming bubble of a closed type it brings the feature of the blood circulation and the composition of the filling gases.

Speaking about the diversity of the structure of the swimming bubble and the peculiarities of its connection with the external environment should not be mentioned about the swimming bubble of herring (sem. Clupeidae). The features of its structure are associated with the peculiarities of the biology of these fish, which are characteristic of significant and sharp vertical migrations. Thus, a typical representative of Seld Pacific Herring Clupea Pallasii makes such migrations from the depths of the sea into the surface layers after plankton, which it eats. With such movements, the volume of gas in the swimming bubble increases sharply by reducing the external pressure, which in the usual case could cause damage to the fish tissues (something similar we observe when fishing from depth - often such catchings are accompanied by a swimming bubble through the mouth of the fish). So that this does not occur, in the process of the evolution of herring, an additional hole is acquired, located in the anal area and connecting the swimming bubble with an external environment. Through it, the "blending" of excessive air occurs, and this process can be controlled by the fish itself with the help of a sphincter here.

For more information about the functioning of the swimming bubble, I will tell in one of the following posts.

Swimming bubble is characteristic of most bone fish. Embryorally it occurs as the gown of the dorsal side of the digestive tube. Many species of the bubble bubble is lost (closed fish), but some it remains for life (open source fish). The swimming bubble performs mainly a hydrostatic function, which is determined by a change in the volume of gases in the bubble and, therefore, leads to a change in the density of the body's body. At open-value fish, the change in the volume of the bubble is achieved by compressing it or, on the contrary, expansion when switching air; In the closed, by absorption or, on the contrary, the release of gases with a special network of gas capillaries (wonderful plexus). The gas filling the swimming bubble is predominantly nitrogen. In some fish, the swimming bubble is associated with a bone system (the so-called Weber apparatus) with an internal ear - webbed, labyrinth. With its participation, the change in the volume of the bubble associated with changes in the position of the fish in the water is transmitted by semicircular channels of the inner ear, i.e. equilibrium body. In addition, Weber apparatus transmits sounds. which are perceived by the surface of the body, resonate with a swimming bubble and are transmitted to the auditory body (membered labyrinth). In general, the appearance of a swimming bubble is probably due to the weighting of the body of the fish in connection with the formation of the bone skeleton.

The swimming bubble can perform hydrostatic, respiratory and sound functions. None of fish leading a bottom lifestyle and in deep-sea fish. Recent buoyancy is provided mainly due to fat due to its incompressibility or due to the lower density of the body of the fish, such as, ansisiterus , golomyanka and fish-drops . In the process of evolution, the swimming bubble was transformed into lungs ground vertebrae.

Description

In the process of embryonic development of fish, the swimming bubble occurs as the spinal gross of the intestinal tube and is located under spine . In the process of further development, the canal connecting the swimming bubble with the esophagus may disappear. Depending on the presence or absence of such a channel, fish are divided into open and closed. At open-to-wear fish ( fizost.) The swimming bubble throughout life is associated with the intestine by an airbag, through which the gases come inside and output. Such fish can outlook air and thus control the volume of the swimming bubble. Related to open support carps , herring , sturgeon other. In adult closed fish ( fisoclists) Air duct bages, and gases are highlighted and absorbed through the red body - thick plexus of blood kapillyarov On the inner wall of the swimming bubble.

Hydrostatic function

The main function of the swimming bubble in fish is hydrostatic. It helps fish to stay at a certain depth, where weight The water displaced by fish is equal to the weight of the fish itself. When the fish actively falls below this level, its body, experiencing greater outdoor pressure from the water side, compressing, squeezing the swimming bubble. At the same time, the weight of the displaced volume of water decreases and becomes less than the weight of the fish and the fish drops down. The lower it is lowered, the stronger the water pressure becomes, the more the body of the fish is squeezed and its rapidly continues. On the contrary, when floating closer to the surface of the gas in the swimming bubble expands and reduces the proportion of fish, which even more pushes the fish to the surface.

Thus, the main purpose of the swimming bubble is to provide zero buoyancy In the zone of the usual habitat of fish, where she does not need to spend energy on maintaining the body at this depth. For example, akula Which there is no swimming bubble, are forced to maintain the depth of its immersion by constant active movement.

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Watch what is a "swimming bubble" in other dictionaries:

    The swimming bubble filled with air bag, thanks to which the knobs can be kept on the way. It is located under the intestine. Due to the presence of a channel connecting the bubble with the intestines, it can be blown away and swell, filling ... Scientific and Technical Encyclopedic Dictionary

    Unpack or paired fish organ, performing hydrostatic, respiratory and sounding function ... Big Encyclopedic Dictionary

    - (Vesica Patatoria), HEPAPED or PAR Fish Organ; Develops as an increase in the front of the intestine. Performs hydrostatich., Some fish flesh. and soundly pleasing functions, as well as the role of the resonator and the converter of sound waves. In some fish P. p. ... ... ... Biological Encyclopedic Dictionary

    Unpack or paired fish organ that performs hydrostatic, respiratory and sound formation functions. * * * Swimming bubble Swimming bubble, unpaired or paired fish organ, performing hydrostatic, respiratory and ... ... encyclopedic Dictionary

    Unpaired or pair of fish organ, developing as an opposite intestinal growth; Can perform hydrostatic, respiratory and sound formation functions, as well as the role of the resonator and the converter of sound waves. At the bobbled, ... ... Great Soviet Encyclopedia

    Unpack or pair of fish organ, performing hydrostatich., Speat. and sound. Functions ... Natural science. encyclopedic Dictionary

    Bubble, bubble, husband. 1. Transparent, hollow and air filled (or some gas) a ball arising in some liquid mass or produced from it and separated due to the pressure of the air jet. Blow bubbles. Bubbles in ... ... Explanatory Dictionary Ushakov

    The appendage of the intestinal canal of fish, very often from it completely disassembled and filled with gases. Ordinary P. Bubble is placed on the spinal side of the animal and plays a large role when swimming, timing to a certain depth (see ... ... Encyclopedic Dictionary F.A. Brockhaus and I.A. Efron

    SUB., M., Upatr. compared. Often morphology: (no) who? bubble to whom? bubble, (see) who? Bubble, who? bubble, about whom? about the bubble; MN. Who? bubbles, (no) who? bubbles, who? Bubbles, (see) who? Bubbles who? bubbles, about whom? About bubbles 1. Bubble ... ... Explanatory dictionary Dmitrieva

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