Sturgeon with a long nose. Sturgeon fish
Scientists have every reason to believe that more than 75 million years ago, sturgeon fish were already on our planet. Therefore, the fact that they have survived to this day cannot but surprise.
Their habitat is sea salt water, and they spawn in fresh water. The sterlet is the smallest among the sturgeons. The length of her body is from 30 cm to 1 m, she weighs from 500 g to 4 kg. Beluga is considered the largest, its weight reaches 2 tons, and its length is 9 m.
Sturgeon fishing is practiced in many countries the globe, not only meat, but also caviar are considered valuable products. It is forbidden to fish during spawning, but poachers break the law, despite the ban and punishment. Influenced on the number of fish and other factors, for example, the deterioration environmental situation, therefore, the names of large representatives of sturgeons can be seen in the international Red Book.
Acquaintance with sturgeons
Before the start of spawning, in spring, sturgeons move to fresh water bodies and settle in places with shallow depths. Numerous offspring are born, first in the form of larvae. Some representatives of sturgeon relocate to fresh water not only for spawning, but also before wintering. They successfully master the bottom, and find their food there - small fish, worms, mollusks and insects.
Features of the structure of the body of sturgeons
Representatives of sturgeons are distinguished by their large weight and size. They have an elongated body, bone shields are arranged in five rows, alternating with bone plates. The snout is cone-shaped, shaped like a shovel. On the muzzle there are two pairs of antennae, a mouth with fleshy lips, no teeth.
Oddly enough, even adult fish do not have vertebral bodies. Representatives of this oldest family on our planet have much in common with sharks, for example, both have splashes.
Growth and puberty
Most sturgeons are centenarians. Individuals begin to spawn in different time, it all depends on the type of fish and the place where it lives. When spawning ends, the fish returns to the sea, gaining weight, in order to go back to spawn a year later.
Sturgeons do not grow as slowly as their puberty occurs. It is not uncommon for females to be ready for spawning at only 20 years of age. On average, this figure is 8-21 years, males become sexually mature earlier, at the age of 5-18 years. For the inhabitants of the Don and the Dnieper, this happens faster, for fish living in the waters of the Volga - longer.
Every year, spawning occurs only in sterlet. Despite the fact that the current in the rivers is fast, this does not affect the eggs. Thanks to the sticky structure, the eggs stick to the pebbles and retain their integrity.
The most popular representatives of sturgeons
- Beluga. These are real centenarians and giants among freshwater fish. The weight of the largest individuals was more than a ton, and the length was four to five meters. Scientists believe that these "record holders" were 65-70, and maybe 100 years old. This fish, resembling a torpedo in shape, is considered the most ancient. Males are smaller than females. Gobies, anchovies, roach, herring, anchovy serve as food for fish. Spawning in females begins with the onset of spring, once every two or four years. The number of eggs in one female can reach 7 million pieces. Its meat is tasty and nutritious, but it is a little tougher than the meat of other sturgeon, caviar is considered a particularly valuable product. It was this fish that suffered more than others from the barbaric destruction by poachers, so they are trying to correct the situation by growing it at specialized enterprises.
Beluga - Russian sturgeon. It can be found in the waters of the Black, Azov and Caspian seas. There are individuals up to two meters long, weighing from 12 to 24 kg. There are cases when the weight of the caught fish was 80 kg, and the age was 50 years. The body of the sturgeon is fusiform, the snout is blunt and short. The color changes from dark gray on the back to white on the belly.
Russian sturgeon - Siberian sturgeon. Judging by the name, it is not difficult to guess where this fish lives. These are the basins of Russian rivers - Kolyma, Ob, Yenisei and Lena. The Siberian sturgeon is a valuable commercial fish. Their fatness is higher than that of other sturgeon representatives. The fish weighs from 9 to 22 kg, but not infrequently this figure reaches 100 kg. Spawning at the Siberian sturgeon begins in the middle of summer. The fish feeds on chironomid larvae, amphipods, and mollusks.
Siberian sturgeon - Stellate sturgeon. This is a very valuable commercial specimen that lives in the waters of the Black, Azov and Caspian Seas, average weight one individual - 7 kg, life expectancy 30 years. The color of the fish, like its relatives, depends on the habitat. Most often, the back is bluish-black, and the belly is white. Sevruga meat is very tasty, valuable and healthy.
Stellate sturgeon - Sterlet. This is a fish that is much smaller than its relatives, on average it weighs no more than 700 g, but there were specimens up to 16 kg. Its length is 40-60 cm, the fish is easily recognizable by its elongated, slightly pointed nose. Life expectancy is 20 years. Puberty in sterlet begins as early as 7 years, therefore, in fish farms they prefer to breed it. Lateral plates and fringed antennae - this is what distinguishes the sterlet from the rest of the sturgeons. Color - from grayish-brown to yellowish-white. The meat of this fish is a delicacy product; sterlet ear is considered especially tasty. The sterlet is found in the waters of the rivers flowing into the Black, Azov and Caspian Sea, in Northern Dvina, Yenisei, Ob. At one time, it was settled in the waters of the Western Dvina, Neman, Onega, Oka and in some reservoirs.
Sterlet
AT tsarist Russia only the richest people could feast on sturgeon. Nowadays, in the habitats of fish, dishes from it are not considered something special. Fish meat contains a large amount of vitamins and other beneficial substances that have a beneficial effect on the human body. All of them are necessary for the maintenance and normal functioning of organs and systems. It is difficult to overestimate the importance that Omega-3 polyunsaturated acid has for our body. It contributes to the normal functioning of brain cells, strengthens the immune system, improves memory. Based on laboratory studies, scientists have concluded that people who regularly eat red fish are less likely to fall into melancholy, they manage to avoid depression and mental disorders. Omega 3 prevents the occurrence of cardiovascular and oncological diseases
Today there are a large number of hybrids that are the result of crossing sturgeon, outwardly they are very similar to their relatives.
(beluga, kaluga, spike, sturgeon, stellate sturgeon, sterlet) - very valuable species. Their meat and caviar are distinguished by high nutritional and taste qualities. In pond farms, it is possible to grow sterlet caught in young age from rivers.
Quite successfully, experiments are being carried out on growing hybrids in ponds. sturgeon fish(for example, a hybrid of a beluga with a sterlet).
Sturgeon fish - fishing (old photo)
- common in the rivers of the basin of the Black, Caspian, White, Kara Seas, and also found in the Danube, Pechora, Dnieper and Don. The body of the fish between the rows of bugs is covered with very small comb-like grains. The lower lip is interrupted in the middle. Antennae fringed.
The shape of the head and snout is very variable: the snout is shortened, sometimes blunted. Dorsal scutes (bone outgrowths) - 10, lateral - 52, abdominal - 10-19. Sterlet can live and develop rapidly both in flowing cold ponds and in carp and crucian ponds. Silt ponds overgrown with vegetation are not suitable for growing sterlet and its hybrids.
In such reservoirs, sterlet meat acquires the smell and taste of mud, which significantly reduces its taste qualities. In filamentous algae, fish become entangled and die. Sterlet grown in ponds grows better than in a river (with a content of at least 7 g of benthic organisms per 1 sq. M of the bottom of the reservoir - chironomids, oligochaetes, etc.).
Sterlet males reach sexual maturity at the age of 4-5 years, and females - at the age of 7-9 years. Spawning takes place annually in May-June at a water temperature of 10-12 °C. The fertility of one female is from 4 to 138 thousand eggs. AT vivo spawning takes place in fast flowing rivers, deep places, on hard ground or occupied by meadow vegetation.
Sterlet caviar is sticky, its development, depending on the water temperature, lasts 6-11 days. The sterlet feeds on the bottom of ponds, especially in sandy areas, mainly on mollusks, worms and larvae of chironomids, in rare cases on zooplankton; eats and artificial feed (sunflower cake, etc.).
After hatching, the fry stay in weakly silted places, feed on small oligochaetes, chironomid larvae, and mollusks. The sterlet does not enter overgrown areas. There is an independent subspecies - the Siberian sterlet. She meets in major rivers Siberia - Ob, Irtysh and Yenisei. Further to the east (Pyasna, Khatanga, Lena, Kolyma, etc.) - absent.
The usual commercial length of the sterlet is 40-75 cm, weight - 0.5-2 kg. At good conditions content, the weight of a sterlet can reach 8 kg. Small sterlet (peak), caught from natural reservoirs, can be reared in ponds that are not inhabited by other fish, located not too far from the place of its fishing (the sterlet does not tolerate transportation over long distances).
Sturgeon. Many years of experience of scientists have proven that the sturgeon and its hybrid with the sterlet grow well and winter in the pond. In terms of growth rates, hybrids are superior to sterlet. They can be successfully fed with agar, feed mixtures containing meat and bone or fish meal.
Sturgeon (lat. Acipenser) is a genus of fish of the sturgeon family
At the same time, artificial feed is poured onto wooden feeders. The fish productivity of sturgeons with artificial feed is 26 kg per 1000 square meters. m of water area. Together with sturgeons, it is possible to grow herbivorous grass carp, which significantly increases the fish productivity of the reservoir.
Sturgeon fry (larvae) obtained from the fish factory are first reared in small galvanized baths, and then released into the pond. By autumn, the weight of a sturgeon underyearling reaches 20-100 g. Sturgeons weighing 20 g and more overwinter well in ordinary wintering ponds. The following year, overwintered fish are planted in feeding ponds.
Sturgeon is a fish of the sturgeon family
The average weight of 7-8 year old sturgeons grown in a pond is 5-6 kg.
Russian sturgeon. Sturgeons are ancient fish.
Beluga (Huso huso) distributed in the basins of the Caspian, Black and Azov seas; is in the Adriatic Sea basin (from where it enters the Po river). Passing fish. Like kaluga, beluga is one of the largest freshwater fish, reaches a ton of weight and length of 4.2 m (at the age of 15), as an exception, up to 1.5 and even up to 2 tons of weight and 9 m of length were indicated.
The average commercial weight of the beluga on the Volga is 70-80 kg, on the Sea of Azov 60-80 kg, in the Danube region of the Black Sea 50-60 kg. In the Caspian Sea, the beluga is ubiquitous. For spawning, it enters mainly the Volga, in smaller quantities - the Urals. Previously, she climbed high along the Volga, to Tver, along the Kama to its upper reaches.
In the Urals, it spawns in the lower reaches and middle reaches (the region of the city of Uralsk). At the end of the XVIII - beginning of the XIX century. entered the Kura in large quantities, now it enters in dozens of copies. Along the Iranian coast of the southern Caspian, the beluga entered Gorgan. The Azov beluga for breeding enters the Don, very few in the Kuban. Previously, it climbed high along the Don, now only up to the Tsimlyansk hydroelectric power station.
From the Black Sea enters the Danube, Dnieper, Dniester. It used to rise along the Dnieper to Kyiv, now it reaches only the Kakhovskaya hydroelectric station; passed along the Dniester to Soroka, now in the lower reaches the Dubossary hydroelectric power station serves as an obstacle. Single specimens entered the Southern Bug, Rioni. Beluga is a long-lived fish, reaching the age of 100 years. The bulk of the males entering the Volga are 13-18 years old, those entering the Kura are 16-21 years old.
Beluga females in the Caspian reach maturity at the age of 16-27 years, mainly at the age of 22-27. Mature males of the Azov beluga were observed at the age of 12-14 years, females - 16-18 years. Fertility, depending on the size of the female, is from 0.5 to 5.0 million eggs. Thus, the Volga beluga 250-259 cm long spawns an average of 937 thousand eggs, Kura of the same size - 686 thousand eggs.
Beluga - old photo
The average fecundity of the walking Volga beluga in 1952 was 715 thousand eggs. Beluga is a predator; begins to prey even as a fry in the river. In the sea it feeds mainly on fish (herring, sprats, gobies, etc.). In the Caspian beluga, even seal pups were found in the stomach. Beluga in nature forms hybrid forms - sterlet x beluga, beluga x sterlet, beluga x stellate sturgeon, beluga x spike, beluga x sturgeon.
On the Volga and on the Don, with the help of artificial insemination, viable hybrids were obtained - beluga X sterlet. These hybrids are introduced into the Sea of Azov and some reservoirs. There have been attempts to grow sturgeon hybrids in pond farms.
Bester. This is a hybrid bred by Russian scientists (Professor N. I. Nikolyukin and others) by crossing the largest of the sturgeon fish - the beluga and the smallest of this family - the sterlet.
Bester it feeds well on natural and artificial food, is hardy, gets sick a little, has an unusually balanced, calm character.
It is currently set up industrial production in many fish farms in Ukraine, Georgia, Moscow region, in Central Asia, in the Baltic States and Belarus.
For these purposes, ordinary carp ponds (only somewhat deepened), cages and other reservoirs are used.
"Red fish" - it was sturgeon fish that was first named with this term. It's not about the color of their meat, as we used to think about salmon, but about the unique value, food and industrial. Unfortunately, so valuable fish is currently on the verge of extinction.
The sturgeon family includes a few representatives that live both in Russia and abroad.
Origin story
This is very ancient view fauna representatives. According to scientists, sturgeon fish appeared already in Cretaceous period. In other words, they co-existed with the dinosaurs. Representatives of the species survived during a great catastrophe, in which a large number of representatives of the animal and plant world did not survive.
Until now, scientists are studying that period of time according to the preserved sturgeons, more according to their subspecies: shovel-nosed.
Features
Fish belonging to the sturgeon family have a peculiar structure that distinguishes them from all other representatives of the class. The main thing that is distinguished at the same time is a distinct chord, rigid cartilaginous. It is she who is the basis of the skeleton, which, by the way, does not have vertebrae, but only cartilage. Moreover, the cranium also consists of the latter.
Another one distinguishing feature enclosed in ganoid scales. It forms a kind of shell, consisting of ossified shields. On top, it contains a dentin-like substance - ganoin, and fish, respectively, are called ganoids.
The enumerated features of sturgeon fish will be incomplete if we do not mention the spray - a hole located on the upper gill cover. It is connected directly to the gills by a special channel. Spatter is also found in sharks.
All types of sturgeon are similar in body shape - spindle-shaped. The difference lies in the snout: in some it is pointed, in others it is xiphoid. At the bottom of the head is a mouth, in front of which there are four whiskers - another feature of this type of fish.
Habitat
Sturgeons are predominantly anadromous, which means that they live in the sea, but spawn in rivers. Moreover, they prefer the cool waters of the northern and middle latitudes: their dense genoid scales are able to withstand low temperatures. The name of the sturgeon leading a migratory lifestyle: two types of sturgeon, Russian and Atlantic, beluga, stellate sturgeon, spike. Only the sterlet does not go to spawn in the sea, it leads settled life in clean rivers with a fairly strong current. 
The distribution area is the seas of the northern hemisphere and the rivers flowing into them. These are, first of all, the Black and Caspian, White and Azov seas. Most often, the species of sturgeon listed above can be found in the Siberian rivers: Ob, Lena, Yenisei. It should immediately be said that this species is on the verge of extinction.
They lead a predominantly bottom lifestyle, feeding on small fish, invertebrates (mollusks or worms), and do not disdain insects. Beluga sturgeon is the only predator that feeds not on bottom organisms, but exclusively on fish.
There is another interesting pattern in the diet of this type of fish: they distribute the food base of the reservoir among themselves: for example, the Russian sturgeon prefers mollusks, the stellate sturgeon prefers worms and various crustaceans, and the sterlet prefers invertebrates.
reproduction
For the most part, sturgeons go to rivers for spawning. They choose those where the bottom is not muddy, but pebbly. Also, such factors as clean water and a fairly fast current are very important for them.
Sturgeons do not lay eggs every year. This is primarily due to the fact that puberty occurs quite late, because these fish are long-lived. The exception is the sterlet, it breeds annually, as it leads a sedentary lifestyle.
Spawning of sturgeon occurs in spring and summer. Caviar is well attached to the pebble bottom, as it has a dense adhesive structure. Hatched fry have a special yolk sac, which is the first source of their nutrition. 
The bag dissolves after some time, and sturgeon cubs begin to feed on protozoa (zooplankton), and even later, having matured, on crustaceans. An exception is the fry of predators, beluga. They do not have a yolk sac, they feed immediately on their own.
Grown up fish in the same summer begin to move into the sea. However, if spawning takes place in reservoirs, it is not uncommon for young animals to stay there for up to two years.
Commercial value
Sturgeon fish are especially valuable in gastronomic terms. From ancient times in Russia they were eaten, and not only meat was valued, but also caviar of a specific black color.
Nutritionists say that the meat of these fish may well replace the meat of mammals, but it is much more useful due to the high content of vitamins and Omega-3 acids - especially beneficial substance. The only limitation is the high fat content: up to 20 percent. In any case, the meat of this group of fish is a great delicacy. Its use reduces the risk of oncology, hypertension and even depression.
Sturgeon fish and its relatives can be consumed in any form, except salted. The fact is that in the meat prepared in this way, toxic substances, due to which you can get severe poisoning.
It is impossible not to mention the great value of black caviar. This is a kind of unspoken symbol of Russia. Since ancient times, this product has decorated festive tables. It is many times more high-calorie and fatter than meat, in addition to a large number vitamins contains "light" proteins, minerals, special nutrients. However, the constant use of it in food can lead to urolithiasis.
The gastronomic value of caviar depends on the color. The best is royal, the one that is obtained from fish over 60 years old. Its color is amber.
Security
Because of its high gastronomic value sturgeon fish were mercilessly caught and exterminated for a very long time. Due to the long period of puberty and growing up, they did not have time to reproduce offspring. Accordingly, the number was catastrophically reduced. At the moment, fish of the Sturgeon family (their photos are presented in the article) are listed not only in the Russian Red Book, but also in the international one.
In addition, the limiting factors are pollution of water bodies (recall that sturgeons live and spawn in exceptionally clean water), the destruction of breeding sites by industrial enterprises, and the construction of reservoirs.
Poaching also plays an important role in population change. Officially, catching all types of sturgeon is prohibited and punishable by law, but some citizens continue it, especially during spawning. Currently, there is talk of banning the harvest of this species of fish in general (until now, fishing for subsequent reproduction is allowed).
Sturgeon fish, the price of which is quite high on the shelves, are sold only in small quantities. Individuals that are not capable of reproduction go into industrial processing.
At the moment, breeding of sturgeon fish species in special reserves and their further release into the natural environment is widely developed.
Sterlet
We will analyze each representative of sturgeon fish. The sterlet is the smallest of all, leading a sedentary lifestyle. In size reaches 1.5 meters, weighing up to 7 kg. But such parameters of sterlet are rare. The average value ranges from 2.5 kg of weight and length of 50-70 cm. The sterlet lives up to 35 years. 
The ability to reproduce comes late: at the age of five. Hence the main limiting factor: the catch occurs before the fish bears offspring.
As for the appearance, here the sterlet is distinguished by quite often located bugs - special bone outgrowths on the body. There are no scales, shields will replace it. The fish has a pointed nose, rather long. Below it are four antennae, almost reaching the mouth.
The belly is yellow, the back is gray-brown. The bugs are light, standing out against the main background. Fins gray color. This is the classic color of the sterlet, however, there are exceptions depending on the habitat.
The fish lives in the basins of the rivers of the Caspian, Azov and Black Seas. Prefers Siberian rivers: Ob, Yenisei, Lena. At the moment, individuals bred in the reserves have been released into the Amur and Oka, as well as the Western Dvina and the Neman. It is too early to say whether the sterlet will take root there or not.
Sturgeon
Sturgeon fish is perhaps the most common of all representatives of its species. At the moment, several types are distinguished, characterized by habitats. So, Lena and Amur, as well as white, Baikal and Atlantic sturgeons are known. Moreover, the latter has a very extensive habitat, which even goes to the borders North America. All these species are either anadromous or sedentary. One thing brings them together: they all spawn exclusively in fresh water. 
The sturgeon differs from other representatives of the species (its photo is given in the review) in gray, which smoothly turns into a lighter, even white, towards the belly. The back is green-yellow. Unlike those of the sterlet, the antennae of the sturgeon are at a sufficient distance from the mouth, rather, they are closer to the edge of the snout. Individuals are very large. So, in 2014, almost seven hundred kilogram sturgeon was caught. However, individuals rarely reach such indicators - their average parameters are 2 meters long and weigh up to 30 kg. Often there are also hundred-kilogram fish. Outwardly, the sturgeon is very similar to the sterlet, only larger. Most widely famous species- Russian and Atlantic.
Russian sturgeon lives in the basins of the Black Sea, as well as the Azov and Caspian. As a rule, it spawns in the Volga and other rivers associated with it. In the past, there were cases of catching spawning fish even in the Moscow River.
Adult individuals live at a depth of up to 100 meters, while young animals are content with a five-meter depth.
One of the main limiting factors is the construction of the Volgograd hydroelectric power station, which has violated the habitat and habitual habitat of the sturgeon. It became simply impossible for fish to return from spawning back to the Caspian Sea.
As for the Atlantic sturgeon, it is currently the largest representative of the species. These are long-lived fish, living up to a hundred years. There have been cases of catching Atlantic sturgeon up to 800 kilograms. The length is also impressive: some individuals reach six meters. Habitat - Baltic and North Sea.
Beluga
Beluga by appearance slightly different from sterlet and sturgeon. It's all about the massive thick body and blunt snout. It is not for nothing that its Latin name is translated as "pig". At the same time, it reaches a very impressive size. In the fishery, cases of catching beluga whales weighing more than 1000 kg were known. At the moment, the average weight ranges from 200 to 300 kilograms. In addition, these fish are also long-lived: the age of some specimens exceeds 100 years. However, the average life expectancy is 45-50 years. 
In addition to a massive body, the beluga is distinguished by a truly large mouth, which is necessary for fish to obtain food. The lips have a width comparable to the width of the head. The antennae are just as big: they easily reach the mouth.
May have winter and spring forms. It depends on where the fish spawns and lives. Since young growth prefers to eat crustaceans, it stays closer to their places of accumulation - river mouths. There, the shells are not so hard and quite small.
Beluga - predatory fish. It feeds on bream, roach and carp. He does not disdain his fry, even relatives in appearance - other sturgeons.
Beluga begins to reproduce very late: females - at 18 years old, males - at 14-15. Main river for spawning - Don. However, the construction of dams that regulate river floods has a huge impact on the decline in numbers.
Stellate sturgeon
The stellate sturgeon is strikingly different from other sturgeons. It can be recognized by its characteristic elongated snout, which makes up to 60% of the fish's head. Actually the whole body of the fish is stretched into a string. In addition to bugs, there are plates on the body of stellate sturgeon that resemble stars in shape. As for the characteristic antennae, they are very short, they do not reach the mouth at all. The lower lip is poorly developed. 
The color of the fish is quite dark: from a black-brown back it smoothly turns into a light, almost white belly.
Sevruga does not reach large sizes like sturgeon or beluga. According to these parameters, it is similar to the sterlet. The average length is from 1.3 to 1.5 meters, weight - from 7 to 15 kilograms. The fish lives long enough, up to 35-40 years.
In nutrition, the fish is unpretentious: it eats as small crustaceans, molluscs, and gobies, sprats and other fish.
The stellate sturgeon lives in the Black and Seas of Azov, in the Caspian prefers its northern part. You can also meet her in the Sea of Marmara, and single copies are found in the Adriatic. For spawning, like all sturgeon fish, it goes to fresh water bodies: the rivers Don, Kuban, Dniester, Bug, Danube and others.
Limiting factors include the construction of dams on rivers where fish breed, pollution of water bodies, and destruction of spawning grounds.
Bester
It often happens among sturgeons interspecific crossing. It happens as in natural environment as well as on an industrial scale. To date, one of the most promising is a hybrid of beluga and sterlet. It's called bester. This fish has taken the best qualities initial individuals: high life expectancy, adaptability to fresh water, predatory type of food (from beluga). From the sterlet, the hybrid received the best gastronomic qualities and the early onset of the reproduction period.
The first individuals were bred in 1952. And after a few years, adult fish were released into the Sea of \u200b\u200bAzov, as well as the Proletarian reservoir.
As for hybrids in the natural environment, they are quite common, so it is almost impossible to track them. This is due to the fact that the number of sturgeons is too low.
Mostly sturgeon species of fish live in salty sea water, and swim to fresh water for spawning. The representatives of the sterlet are endowed with the smallest dimensions, which on average have sizes from 30 cm to 1 m and weight from half a kilogram to 4 kg. The largest representative of the species is the beluga, which reaches 2 tons of mass and 9 m in length.
Today, sturgeon fishing is the world's largest fishery. In addition to meat, this species is also valuable for its caviar. During spawning, fishing is prohibited. But poaching flourishes everywhere, even though they are actively fighting it.
External characteristics and structure
Representatives of sturgeons are one of the largest in the water expanses of rivers and seas, they have an elongated body, which is covered with five rows of bone shields: 1 on the back, 2 on the sides and 2 on the belly. Between them are bone plates. Sturgeon is a fish with an elongated, cone-shaped snout, similar to a shovel. Below the head are the fleshy lips of the mouth, which in several species has a crescent shape and is also located on the sides. Below the muzzle are 4 antennae. The jaw has a retractable shape without teeth.
The ray fin on the chest is considerably thickened and looks like a spine, while the dorsal fin is slightly pushed back. located under the spine and connected to the esophagus. Skeleton has an invertebrate, cartilaginous structure with preservation of the notochord. The membranes of 4 gills are attached to the pharynx and merge at the throat, there are also 2 more accessory gills.
general information
In most cases, all sturgeon species of fish at the time of spawning go into fresh springs, in shallow water. Their population is quite prolific, and already sufficiently mature and large individuals can produce millions of larvae. Spawning takes place in the spring. It should be noted that some species, in addition to spawning, enter the waters of rivers and winter quarters. They live mainly at the bottom of water bodies, feed on small fish, worms, molluscs and insects.
puberty
The sturgeon family, the list of which includes about 2 dozen varieties, is represented mainly by centenarians. The period of readiness of an individual for spawning comes in different ways depending on the habitat and type of fish. At this time, you can observe how the shallow water of some freshwater rivers is simply teeming with sturgeon representatives. After spawning, caviar-producing individuals descend along the river into the sea, increase in size, and develop. The following year, they again go to spawn.
The growth of sturgeon, as well as maturation, is very slow. Some species are ready to breed only at the age of 20 years. In females, puberty occurs in the period from 8 to 21 years, in males from 5 to 18 years. But regarding weight, we can say that sturgeon species of fish are the fastest growing inhabitants of reservoirs. The sturgeons of the Dnieper and Don reach puberty the fastest, and the inhabitants of the Volga much longer.
spawning
Not all female sturgeons spawn every year. Only the sterlet breeds annually. Representatives of sturgeons spawn in the spring-summer season in the fresh waters of rivers with fast current. It has a sticky structure, so it is perfectly attached to limestone or pebbles.
Fry
The larvae emerging from the eggs have a yolk sac, which determines the endogenous feeding period. The fry can independently consume external food by the time when the endogenous bladder is completely resolved. Then comes the exogenous period of active nutrition. After that, the fry may linger in the river waters, but often the larvae roll into the sea in the summer of the same year. This is how sturgeons breed. Photos of their various representatives can be viewed in this article.
Feeding fry
The first food for sturgeon fry is zooplankton, such as daphnia. After they begin to eat representatives of crustaceans:
* gammarids,
* chironomids,
The exception is the predatory beluga fry, which do not have a yolk sac and even during their stay in the river begin to eat on their own.
Further development of sturgeon to sexually mature age occurs in sea waters. Anadromous representatives of sturgeons are divided into spring and winter species. For the former, it is customary to enter the rivers in the spring. Their spawning occurs almost immediately. Winter crops enter the river from autumn, spend the winter, and spawn the next spring.
Classification of the sturgeon family
Initially, two genera of sturgeons were distinguished:
* skafir.
All of them in total numbered about 25 which were found only in temperate latitudes: Asia, Europe and North America. Over time, the population of some of them disappeared.
Kinds
Sturgeon species of fish are very popular in the fishery. Today, 17 varieties of sturgeon representatives are known. The most popular types are:
1. Beluga is the most ancient type of freshwater fish. Its life cycle can last 100 years. can reach 5 m in length and have a mass of 2 tons. The body of the fish is similar in shape to a torpedo, covered with protective bone plates in 5 rows, dark gray above and white below. From the bottom of the muzzle there are antennae that provide the scent to the fish, and a sickle-shaped mouth. Females are larger than males. Beluga is a predator that most often feeds on anchovies, gobies, herring, vobla and anchovy. Females spawn every 2-4 years in the spring.
2. Russian sturgeon - a fish with a spindle-shaped body with a short, blunt snout. The antennae are located at the end of the mouth. Most often, the fish has a grayish-black color on top, grayish-brown sides and a white belly. Russian sturgeon reaches a maximum length of 3 m and can weigh up to 115 kg. Wherein life cycle reaches the age of 50. In nature, sturgeon can form hybrids with sterlet, beluga, spike and stellate sturgeon. This happens extremely rarely, but similar hybrids can be found. Fish habitat: Azov, Caspian and Black seas.
3. Siberian sturgeon. The body of the fish is covered with numerous fulcra and bony plates, the mouth is retractable. This fish has no teeth. There are 4 antennae in front of the mouth. Habitats of the Siberian sturgeon: the basins of the Yenisei, Ob, Lena and Kolyma. The maximum fish grows up to 3 m in length, reaches a weight of 200 kg and can live up to 60 years. Spawning occurs in the middle of summer. The sturgeon feeds on organisms that live at the bottom of the river: mollusks, amphipods, and chironomid larvae.
4. The stellate sturgeon lives in the basins of the Azov, Chernoy and Ryba stellate sturgeon is winter and spring. The elongated body of the stellate sturgeon is characterized by the presence of a long nose, a convex forehead, narrow and smooth antennae, and a poorly developed lower lip. From the side and from above the body of the fish is covered with a dense cover of scutes. The back and sides are bluish-black in color, and the belly is white. The stellate sturgeon rarely reaches more than 5 m in length and 50 kg of weight.
5. Sterlet is one of the smallest fish among sturgeons, it reaches 1.25 m in length and can weigh up to 16 kg. It has an elongated, narrow antennae that reaches the mouth, touching scutes on the sides, and a bisected lower lip. In addition to the plates on the body that are customary for sturgeon, the sterlet has closely interlocking scutes on the back. Depending on the habitat, the fish may have different color, however, often its back is a grayish-brown hue, and its belly is yellowish-white. The fins are gray throughout. Also, the sterlet is blunt-nosed and sharp-nosed. The fish is found exclusively in the north of Siberia.
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