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Sterlet fish belongs to the sturgeon family and is considered one of the most ancient fish species. According to experts, her ancestors appeared somewhere at the end of the Silurian period. Although the sterlet is small in size, it resembles its relatives, such as beluga, stellate sturgeon, sturgeon, spike and others. Sturgeon has long been a valuable species of fish, so the pace of its fishing has led to the fact that in our time its fishing is considered illegal, and the fish is under protection.
Sterlet fish: description
The sterlet is a representative of a subclass of cartilaginous fish, therefore they have a scientific name – ganoids. For all sturgeons, it is characteristic that their scales look like bone plates that cover the body of the fish, which has a spindle shape.
Appearance
Sterlet is the smallest representative of sturgeon species, as it rarely grows to a size of 1,3 meters. The average size of individuals varies within half a meter. With a weight of not more than 2 kg.
The sterlet is distinguished by an elongated body and an elongated triangular head, while the head is relatively large in relation to the body. The snout is elongated, closer to conical, and the lower lip is divided into 2 parts. By this characteristic feature, it is easy to distinguish the sterlet from its relatives. In the lower part of the snout there are antennae in the form of a fringe, which can also be seen in other representatives of sturgeons.
Interesting fact! It is known about 2 varieties of sterlet: sharp-nosed, which is classified as a classic species, and blunt-nosed, the edge of the muzzle of which is distinguished by a peculiar rounding.
The head is protected from above by fused scutes, and the body is covered with ganoid scales with a large number of bugs, interspersed with comb-like protrusions similar to grains. In the sterlet, the dorsal fin is shifted closer to the tail, and the tail differs in that its upper part is somewhat longer than the lower one.
The classic coloration of the sterlet is distinguished by dark colors and, as a rule, has a grayish-brown hue, with the presence of pale yellow tones. The second variety of sterlet does not have a bifurcation of the lower lip, and the number of bugs in it is the largest and can reach 50 pieces. The colors of the belly in both species are almost the same and differ in light tones, and sometimes almost white.
STERLET. What fish are silent about 50
Character and lifestyle
The sterlet belongs to the predatory fish species. She prefers to live only in rivers with clean and clear water, in conditions of flow. It can swim in the seas, but at the same time it stays closer to the mouths of the rivers.
In summer, the fish prefers to be in small sections of the river, and young individuals are found in narrow channels or bays, near the mouths. With the onset of cold weather, the fish goes to the wintering pits, where it waits for the arrival of spring. During the period of cold weather, the sterlet practically does not move and does not eat anything. After the ice melts, the fish leave the wintering pits and move up the river to continue their lineage.
Interesting to know! Unlike other representatives of sturgeon fish species, which prefer to lead an isolated lifestyle, the sterlet prefers to stay in numerous flocks. She even hibernates surrounded by numerous of her relatives.
At the bottom of the pit, several hundred sterlets can winter, which are quite tightly pressed against each other. This, to some extent, prevents them from moving their fins and gills.
How long does a sterlet live
Sturgeons have a rather long lifespan, and the sterlet is no exception. It is able to live up to 30 years, but compared to lake sturgeon, which live up to 80 years, this is a trifle.
Sexual dimorphism
This fish has practically no sexual dimorphism, so it is almost impossible to distinguish females from males. Individuals of both sexes have almost the same size and color of the body, and the body is covered with almost the same number of bony protrusions.
Range, habitats
Sterlet fish is found in rivers flowing into the Azov, Black and Caspian Seas, as well as in more northern regions, along which rivers such as the Ob, Yenisei, and Northern Dvina flow. In addition, sterlet is also found in the basins of such lakes as Ladoga and Onega. It has also been artificially settled in such water bodies as the Neman River, the Pechora River and the Oka River, including some large reservoirs.
Fish diet
Sterlet fish is a predatory fish that feeds mainly on small invertebrates due to its small size. Moreover, the fish eats both bottom living objects and living organisms located in the water column. Especially willingly, she eats caviar of other fish. Too large, adults prey on small fish.
Interesting fact! Representatives of different sexes eat differently. This is due to the fact that females mainly stick to the bottom area, while males stay more in the water column. The sterlet goes hunting only at night.
Sterlet fry, born, eat bioplankton and other microscopic microorganisms. As individuals grow older, they gradually switch to feeding on larger microorganisms.
Breeding process
Females reach sexual maturity at the age of 7,5 years, and males at 4,5 years of age. Moreover, the sterlet does not breed annually, but after a year.
This enables the females to fully recover from the spawning process, since it takes a lot of strength and energy from the fish.
The sterlet spawns in the conditions of the end of spring and the beginning of summer. To do this, it is necessary that the water warms up to + 8- + 20 degrees, although the optimal threshold for these species is about + 12,5 degrees. There are times when fish spawning begins earlier or later than certain dates due to weather conditions. In addition, the level of spring waters also affects the beginning of the spawning process.
The Volga sterlet differs in that it does not spawn at the same time. As a rule, individuals that live in the upper reaches of the river spawn somewhat earlier than those individuals that inhabit the lower reaches of the river. This is due to the fact that the spring flood occurs earlier precisely in the upper reaches of the Volga and then gradually spreads to its lower reaches. For spawning, the fish chooses areas of the reservoir, where there is a rapid current, and the water is crystal clear. In this case, the bottom of the reservoir should be solid, covered with pebbles. Sterlet fish is quite prolific, since the female can lay more than 15 thousand eggs at a time.
The sterlet lays rather sticky eggs, which develop at the bottom for several days, after which the sterlet fry appear from the eggs. At the same time, they stay in the yolk sac for up to ten days. When the yolk sac disappears, the size of individuals reaches no more than 1.5 cm in length. Sterlet fry bear little resemblance to adults. Their mouth is very small with a cross section, and the antennae, in the form of a fringe, are almost the same size. As for the lower lip, it can already be divided into 2 parts, as in adults of this species. The head is covered on top with numerous small spines, and the color of the fry is somewhat darker than that of adults. This is especially noticeable closer to the tail of the fry.
After birth, the fry remain in these places for a long time, and only with the advent of autumn, when the juveniles reach a size of about 20 cm, do they roll downstream. Representatives of different sexes grow at the same rate, while they practically do not differ from each other. The coloring doesn’t tell much either.
Interesting to know! The sterlet often interbreeds with other members of this family. At that time, having crossed the beluga and the sterlet, it was possible to obtain a rather valuable hybrid – bester. Since the 50s, this hybrid has been considered an object of industrial interest to this day.
The hybrid differs in that it contains the main advantages of both species. Bester is well and quickly gaining weight and growing, which is typical for beluga. In addition, individuals of the hybrid mature much faster in terms of spawning, which allows the process of reproduction of the species to be carried out much faster, especially in captivity.
Natural enemies of the sterlet
The sterlet prefers to stay in the bottom layers of water, so it does not have many natural enemies. The main threat to fish comes when the fish spawned and fry emerged from it, which become prey for other predatory fish. Moreover, caviar can also be eaten by its relatives, if they find a laying of caviar. For young fish, catfish and beluga are the most dangerous.
The status of the species and its abundance
Still, some ten years ago, this representative of the sturgeon family did not show any negative signs indicating that he would soon be assigned the status of “Vulnerable Species”. And all this is due to the fact that water resources are polluted at a high rate, and the sterlet is able to live exclusively in clean water. In addition, poachers cause great damage to the population of this fish, the fight against which is not carried out properly. As a result, the sterlet is now listed in the Red Book as an endangered species.
Huge sterlet. Try to catch one. Catching sterlet on donks. Alloy fishing.
Fishing value
Somewhere in the middle of the 20th century, sterlet was caught on a normal commercial scale, since it was considered the same ordinary fish. As a result of active fishing, sterlet populations began to decrease at the same high rate, which led to the fact that its fishing in the natural environment is prohibited. Despite this fact, this fish can be found on store shelves in any form, both fresh, frozen, and canned, as well as salted or smoked. A natural question arises, but where does the sterlet come from, if it is practically not caught?
The thing is that the world exists not only from poachers, but also from people who do not want this species to disappear forever. By the way, this is also true in relation to many other species of fish that are threatened with extinction. As a result, fish farms appeared, in which, under conditions close to natural, they began to breed sterlet. At first, efforts were made to at least preserve this endangered species. As a result of such efforts, it was possible not only to save the species, but also to make sure that the sterlet again became a common commercial fish. Although this is not so easy, since fish grown in captivity is inferior in quality to that grown in natural conditions. And, nevertheless, it was possible to revive a lot of recipes for cooking dishes from this fish. Sterlet grown under artificial conditions is not cheap, as are dishes prepared from it. And yet it is worth noting that artificial breeding in fish farm conditions is a great chance for the species not to disappear forever. Moreover, this is also true in relation to other types of fish, which can expect the same ending.
It is important to know! The sterlet differs from other representatives of this family not only in the smallest size, but also in the ability to throw eggs earlier than other sturgeons.
This became possible due to the fact that the sterlet is considered a rather unpretentious fish to eat. In addition, it is suitable for breeding hybrids in captivity, such as bester, for example. Despite the fact that the sterlet is considered an endangered species these days, the fish still have a great chance of survival, thanks to the fact that there are people who will not allow this to happen.
Useful Properties
Not only the sterlet itself is considered useful, but also its caviar, which is not inferior in quality to beluga caviar, while the size of the eggs is somewhat smaller than sturgeon caviar.
100 grams of sterlet meat contains only 88 kcal, which makes it indispensable for dietary nutrition. The meat of this fish contains a whole complex of vitamins and microelements, such as zinc, chromium, molybdenum, nickel and others, as well as vitamins of the PP group. Of particular interest are non-fatty acids of the omega-3 type, which have a positive effect on the performance of the brain and ocular circulation. If you eat sterlet meat at least a couple of times a week, you can maintain the working capacity of the cardiovascular system, thereby reducing the risk of a heart attack.
According to scientists, the use of oily fish has a beneficial effect on the skin, improves vision and stimulates the central nervous system.
Such a microelement as fluorine helps to strengthen bones, including teeth, making them more resistant to caries.
It is believed that it is most preferable to make aspic from sterlet meat, cook fish soup, use kulebyak and pies as a filling for baking. In addition, fish can be baked or fried on a spit. To prepare sterlet fillet, after cutting it, it is better to freeze the fish a little. After such a procedure, it is easier to remove the skin from it and just as easily remove the bones. When preparing sterlet dishes, you should always remember that prolonged heat treatment destroys most of the nutrients. The most useful fish is considered if it is consumed raw, that is, salted or pickled. It is no less useful in boiled form, but, as for fried fish, it is the least useful, and besides, it is also harmful, since it is heavy on the stomach. Therefore, only healthy people who do not suffer from digestive tract problems can eat such fish.
As for the dangerous properties of fish, there are practically none, except that a person may have a personal intolerance to seafood. It should also not be used by people with poor pancreatic function, which can be aggravated by polyunsaturated fatty acids.
In conclusion
Sterlet fish needs to be boiled for about 15 minutes so that as many nutrients as possible remain in it. By the way, this is typical for other types of fish. It is believed that sterlet ear is the most delicious and rich. The main thing when cooking is not to overdo it.
In tsarist times, when barge haulers on the Volga moved barges along the river, they ate rich sterlet fish soup. This helped them to restore strength and energy. In those days, such fish were in abundance, which cannot be said about our days. If we talk about the natural enemies of this fish, then the main enemy is a person, since he not only catches it at a fast pace, but also pollutes water resources. As a rule, in such conditions, the fish simply cannot physically live. This leads to a decrease in the number of fish stocks, which are so necessary for normal human life.
Of course, it cannot be said that a person does not do anything in terms of preserving the species. Of course, it does, but these efforts may not be enough. To prevent the worst from happening, there is a lot of work ahead, and the work is hard and very costly.
Catching wild STERLET on the Vyatka river.