Where do sturgeon species live? Sturgeon fish

Beluga (Huso huso) Description: Beluga (Huso huso) is the largest fish found in fresh water ah, since in some cases it reaches a length of several meters and a weight of up to 1120, and in former times more than 1600 kg. In addition to its size, Beluga (Huso huso) is easily distinguished from all other sturgeon fish by its thick cylindrical body and short […]

Kaluga (lat. Huso dauricus) is a freshwater fish of the beluga genus, the sturgeon family. Length up to 5.6 m, weighs up to 1 ton. Mouth large, semi-lunar. Kaluga is widespread in the Amur basin, found in Arguni and Shilka, and in the Sungari. It does not go out to sea beyond the Amur Estuary. There are anadromous, estuary, fast-growing kaluga that rises to spawn in the Amur from the estuary, […]

Shovelnoss (lat. Scaphirhynchus platorhynchus) - river fish weighing up to 2-3, rarely up to 4.4 kg and up to 60-90 cm long, rarely up to 130 cm; characterized by a very long, flattened caudal peduncle, covered like a shell with bony plates; the tail filament, in contrast to the pseudopathophos, is absent or small; the swim bladder is large, the eyes are small. Spreading. Amu Darya and its tributaries from Fayzabad-kala […]

Sturgeon (lat. Acipenser) is a genus of fish of the sturgeon family. Freshwater and anadromous forms. Body length - up to 3 m; weigh up to 200 kg (Baltic sturgeon). There are 16-18 species, some of which are listed in the Red Book. Contents [remove] Genus Acipenser The genus Acipenser is characterized by the following characters: longitudinal rows of bony scutes do not merge with each other on the tail; there are splash holes, [...]

Sterlet is a fish of the sturgeon family. Body length up to 125 cm, weighs up to 16 kg (usually less). Among other sturgeons, it is distinguished by the earliest onset of sexual maturity: males spawn for the first time at the age of 4-5 years, females - 7-8 years. Fertility is 4-140 thousand eggs. Spawns in May, usually in the beds of upper rivers. The eggs are sticky and are deposited on rocky and pebble soil. She […]

Sturgeon is a fish that represents the sturgeon family. It can have a semi-anadromous, freshwater or anadromous form. This is one of the most valuable fish, the size of which can reach several meters, and the weight - several centners: the photo below shows the largest sturgeon caught in the Baltic Sea.

Varieties

There are 19 sturgeons in their family various types, which superficially resemble each other. In the past, there were dozens of species, but most of them became extinct due to overfishing by humans. For the fisherman, the greatest interest is:

• Atlantic sturgeon is a marine representative that lives in the salty waters of the Atlantic Ocean, an anadromous form;
• Baikal sturgeon, which is a semi-anadromous form;
• Lena sturgeon - residential form;
• Amur sturgeon - residential form;
• White sturgeon, a photo of which you can see below the list.

From the name it is clear that fish such as the Amur sturgeon and Lena sturgeon are found in the Amur and Lena rivers, respectively: they are located on the territory of our country. The Baikal sturgeon is found in Lake Baikal, and the Atlantic sturgeon, like the white sturgeon, is found in the ocean and swims into rivers only to reproduce. Moreover, fish, regardless of its form, can only reproduce in fresh water - in rivers. Therefore, the White sturgeon, together with the Atlantic sturgeon, the photo of which is presented below, rises into the rivers of Canada. The Baikal sturgeon, Lena sturgeon and Amur sturgeon remain in place, since they already live in fresh waters, although they can also rise from the lake along streams and rivers.

Atlantic sturgeon is a species that needs special attention. The Atlantic sturgeon deserves this because it is the most massive and largest representative of the sturgeon family. Atlantic sturgeon is found in the waters of the Northern and Baltic Sea. This species is already listed in the Red Book as a species on the verge of extinction. The maximum recorded age to which an Atlantic sturgeon can live is a hundred years, while its body weight can reach 4 centners (according to some sources, even 800 kilograms), and its body length can be 6 meters.

There is an aquarium species of sturgeon. This is a small fish, the length of which does not exceed 18 centimeters. The aquarium species in appearance is almost like an Atlantic sturgeon, only very small. Compare the photo above, which shows an Atlantic sturgeon, and the photo below, which shows an aquarium species. The only difference is that aquarium fish have fewer white spots on their body.

Lifestyle

This genus of sturgeon has special distinctive features that are characteristic only of it. The signs are that on the tail the rows of bone bugs and scutes located longitudinally do not merge with each other. The rays belonging to the caudal fin bend around the end of the tail. The fish has specific squirts.

Most representatives of the sturgeon family, which reach truly gigantic sizes, live in the north temperate climate zone. It is there that fishermen manage to catch their record specimens, which remain the most important trophy throughout for long years. The main part of sturgeon is a migratory form of fish, which begins to rise up the river from the seas in the spring. In such cases, the fish often remain over the winter until the next spawning period. Some species are freshwater, and freshwater fish live either in lakes or in rivers: from the lake they rise up rivers and streams, like anadromous species.

The genus is distributed throughout Eurasia, as well as in the waters of North America. The most extensive habitat belongs to the American or Atlantic species of sturgeon: it is found both in European and American reservoirs. But it is believed that in European rivers individuals of this species swim by pure chance. But, according to some sources, the fish should normally be found in both Europe and America, since this is its habitat.

These representatives of the ichthyofauna try to stay mainly near the bottom surface. The fish feeds like a predator: they eat worms, mollusks and fish. Aquarium fish belonging to the sturgeon family can also attack fish, so cohabitants in the aquarium must be chosen very carefully. Small fish will certainly become prey, and too large fish will become competitors in the food chain.

Sturgeon spawning occurs in summer and autumn: it’s different for everyone, and the spawning period is quite extended in time. During the spawning period, it does not feed: the female’s abdomen contains eggs, the mass of which is about a quarter of the mass of the individual itself. The fertility of sturgeon females is very high: one individual produces several million eggs per spawn, but this does not save most species from extinction. This is due to the fact that people catch them carelessly: in the photo, poachers are catching black caviar. The world's sturgeon stock is concentrated in the Caspian Sea: 90% of the total lives there.

Thus, sturgeon is such a valuable fish that it suffers from this, being on the verge of extinction today. Nutritious, delicious, tender meat, almost boneless, worthy of a truly royal table. What can we say about black caviar, which is superior in value and nutritional value to red caviar.

The sturgeon family belongs to the delicious species of fish, united by a common name - red fish. Moreover, the definition “red” does not characterize the color of the meat. It is associated with the ancient, historically established meaning of the word - beautiful, best, rare, expensive.

Sturgeon is the most valuable commercial fish, forming part of the national wealth. Black caviar is unique business card Russian exports.

General description of the family

Sturgeon belongs to the class of ray-finned fish, subclass cartilaginous ganoids. This is a very large (up to 6 meters) fish, its weight can reach 800 kg. In fossil form, sturgeons have been known since Cretaceous period, that is, 70−80 million years ago. They were very widespread, as evidenced by the location of modern species throughout the planet.

The main difference between fish of the sturgeon family is the absence of a bony skeleton. This fish, one of the oldest on earth, has a chord instead of a spine, and retains it throughout its life.

What does sturgeon and other representatives of this family look like? can be represented by the main external features:

The sturgeon family is not only one of the most ancient, but also the longest-lived fish. Their lifespan is the same as that of humans. There are real centenarians, whose age is more than 100 years. How long a sturgeon lives depends on its species. Some of them live only 40-60 years, but there is information describing large deep-dwelling individuals that have lived up to 150 years.

Main habitats

Many people are confused by the question: is sturgeon a sea or river fish? It is impossible to determine its affiliation unambiguously. Most species of sturgeon feel great in any water, but for spawning they need fast river flows and a hard rocky or sandy bottom.

Sturgeons are divided into the following types according to their habitats:

The places where the sturgeon lives should be rich in food, which for it are mollusks, crayfish and crustaceans, mysids, worms, lampreys and fish.

The most famous representatives

The sturgeon family includes 17 species, most of them are extremely rare, some are listed in the Red Book:

Commercial importance of sturgeon

Sturgeon - a delicious and expensive delicacy, good in any form. Sturgeon or sterlet fish soup is a classic of Russian gourmet cuisine. It is also fried, stewed, salted, smoked, and dried. Russia is the largest supplier of sturgeon meat on the world market.

Black caviar - valuable, useful, high-calorie product. Small black caviar is the main difference between the sturgeon family and other types of red fish.

Large swim bladders are used to make fish glue.

Vizigi - product, used as food, is made from the dorsal string of sturgeon.

A very important quality of most types of sturgeon fish is that they are suitable for artificial breeding. This allows you to control the population size and prevent the extinction of rare and small breeds. In addition, as a result of numerous selection experiments, it was possible to obtain the most viable hybrids with the best taste and commercial properties.

Artificial reproduction - the path to the development of the fishing industry and the expansion of industrial production of sturgeon meat and black caviar, which is important for maintaining Russia’s position in the global fishery market.

This family includes anadromous, semi-anadromous and freshwater fish inhabiting the waters of Europe, Northern Asia and North America.

Sturgeons are characterized by an elongated fusiform body, on which there are five rows of bony scutes: one dorsal, two lateral and two ventral. Small bone grains and plates are scattered between the rows of beetles. The snout is elongated, conical or spatulate. The lower mouth, in the form of a transverse slit, or semilunar, extends in the shape of a tube, bordered by fleshy lips, toothless; Only the fry develop weak teeth, which subsequently disappear. On the underside of the snout, in front of the mouth, there are four antennae in a transverse row. The anterior (marginal) ray of the pectoral fin is well developed and transformed into a spine. The age of the sturgeon is determined from the transverse cuts of this ray. The dorsal fin is carried far back. The swim bladder is usually well developed (only in some sturgeons is it rudimentary, for example, in pseudoshovelfish).

The internal skeleton is cartilaginous, the notochord is preserved throughout life, there are no vertebrae. Sturgeons are fish with a long lifespan life cycle. Beluga lives up to 100 years or more, Russian sturgeon - up to 50, stellate sturgeon - up to 30 years. The age limit of the sterlet, the least durable among the sturgeon species, reaches 20–22 years.

Sturgeons (with the exception of sterlet and shovelnose) become sexually mature late. U different types and even for the same species in different basins, the age of maturation varies greatly, but on average, males of anadromous sturgeon species reach sexual maturity no earlier than 10–12 years, females no earlier than 12–15 years. The Azov sturgeon are the most precocious, entering the Don and Kuban for breeding.

The same fish does not reproduce every year and several times during its life. A large number of age groups of spawners participate in spawning. All sturgeon lay eggs in rivers, in areas with pebble or pebble-sand soil, in fast currents, in conditions of good oxygen supply. Spawning does not occur in the marine environment or in stagnant freshwater bodies. Migratory species, as a rule, do not feed during the spawning period. There are two types of spawning grounds: in areas of the rocky floodplain flooded by spring floods and in channel ridges located at considerable depths. Spawning occurs in spring and summer, usually at a water temperature of at least 15–20 °C. The eggs are sticky and after fertilization they are firmly attached to stones and pebbles. The incubation period is short, only a few days (from two to ten). Sturgeon larvae hatching from eggs have a fairly large yolk sac and at first live off its nutrients. As the yolk sac dissolves, they switch to external (exogenous) nutrition. Sturgeon larvae first feed on planktonic crustaceans (daphnia, cyclops), then the fry begin to eat mysids, gammarids, oligochaetes and chironomid larvae.

The juveniles of anadromous sturgeon species (beluga, stellate sturgeon, thorn, Russian sturgeon, Atlantic sturgeon, etc.) after hatching in the same summer, migrate to the pre-estuarine spaces. Only in some of them, for example, in the Russian sturgeon and thorn, some of the juveniles can stay in the river for up to a year or more. Adults of anadromous sturgeon also go to sea after spawning.

The main food of most sturgeon species is bottom and benthic invertebrates: crustaceans, worms, mollusks, chironomid larvae. By the nature of their diet, they are typical benthophages. Only the largest sturgeon - beluga and kaluga - are predators. The most important feeding areas for sturgeon, where their main stocks are concentrated, are the north of the Caspian Sea, the Sea of ​​Azov, and the northwestern part of the Black Sea. Semi-anadromous species of sturgeon (Siberian sturgeon, Amur sturgeon, Kaluga) feed in deltaic and pre-estuarine spaces large rivers(Ob, Yenisei, Lena, Amur), and in the spring they climb up them for spawning.

Beluga (Huso huso) - above and Amu Darya shovelnose (Pseudoscaphirhynchus kaufmanni) - below"

Sturgeon are fast-growing fish that effectively use the food resources of water bodies. It is interesting to note that species living in the same basin diverge quite widely in their nutritional spectrum and seem to complement each other. If we take, for example, the Caspian basin, then in the “bouquet” of sturgeon species living here, beluga is a typical predator, Russian sturgeon mainly feeds on mollusks, sturgeon prefers worms and crustaceans, and freshwater sterlet eats small bottom invertebrates of the river (mainly chironomid larvae) . In this way, maximum use of the reservoir's food supply is achieved.

Anadromous sturgeon species are characterized by complex intraspecific differentiation and the presence of so-called “winter” and “spring” races. This phenomenon was first described for. some species of fish (sturgeon, salmon) by the outstanding Russian ichthyologist, academician L.S. Berg, and its biological meaning was revealed. Winter forms of sturgeon enter rivers at the end of summer and autumn with immature reproductive products, climb them quite high, overwinter in rivers in pits and spawn in the spring of the following year. Spring fish go to rivers in early spring with gonads ready for spawning, rise along them low and reproduce “on the fly” in late spring - early summer of the same year. The degree of complexity of such differentiation depends primarily on the length and water content of the river: in large rivers (Volga, Ural) both forms are well represented; in relatively small ones, such as Kura, spring forms predominate, which are usually smaller in size than winter ones.

The biological significance of winter and spring races in fish (including sturgeon) apparently lies in ensuring the fullest use of the spawning grounds available in the river basin, including those located in its upper sections, which fish cannot reach in one season.

Subsequently, the famous domestic ichthyologist, Professor N.L. Gerbilsky, in some species of sturgeon (Russian sturgeon, stellate sturgeon, beluga) within the winter and spring races, even smaller biological groups were discovered, also differing in the time of movement and spawning, the state of the gonads during the period entry into rivers, length of migration route, etc.

The question of the hereditary fixation of seasonal races and biological groups in sturgeons remains open to this day. Some researchers deny the possibility of crossing in nature individuals of different intraspecific forms in sturgeons and consider them as genetically determined; others, on the contrary, do not recognize their strict genetic fixation and believe that under certain conditions a transition and exchange of individuals between these groups is possible.

Different species of sturgeon in nature quite easily interbreed with each other, forming hybrid forms. Hybrids between thorn and stellate sturgeon, sterlet and Russian sturgeon, sterlet and stellate sturgeon, Kaluga and Amur sturgeon, Siberian sturgeon and sterlet and other variants are known and described. IN Lately Due to the sharp reduction in spawning areas in rivers caused by hydraulic construction and significant concentrations of producers of different species on them, the number of hybrid forms of sturgeon is increasing.

In the sturgeon family, there is a subfamily of sturgeons (Acipenserinae) with the genera: belugas (Huso) and sturgeons (Acipenser) and a subfamily of shovelnose (Scaphirhynchinae) with the genera: American shovelnose (Scaphirhynchus) and Central Asian pseudoshovel (Pseudoscaphirhynchus).

Shovelnoses (subfamily Scaphirhynchinae) are well distinguished from the sturgeon proper (subfamily Acipenserinae) by a very wide flattened snout with sharp edges, as well as the absence or poor development sprinklers.

The largest sturgeon fish reach the size of beluga and kaluga (genus Huso), the distinctive features of which are big mouth in the form of a semilunar slit and gill membranes fused together, forming a free fold.

They differ from each other in that in the dorsal row of bugs the first one (from the head) is the largest in the kaluga, and the smallest in the beluga.

Kaluga (Huso dauricus) inhabits the Amur basin from the estuary to its upper reaches. Found in Ussuri, Sungari, Shilka, Arguni, Zeya, Onon. It does not go out to sea beyond the estuary. There are two forms of kaluga: estuary, semi-anadromous, fast-growing, entering the Amur to spawn, and smaller, riverine, which does not make large movements along the river and forms several local herds.

One of the largest freshwater fish, reaching a length of 3.7 m and a weight of 380 kg; In the past, specimens over 5m in length have been caught. The usual fishing weight of kaluga is 50–100 kg. The maximum recorded age for this fish is 55 years.

Kaluga becomes sexually mature very late: males are at the age of 17–18 years, females – at 18–22 years. The length of the fish is about 220cm. Kaluga breeds in the summer, in June – July, in deep places with fast currents and pebbly soil.

Its spawning grounds are scattered from Shilka to Tyr and below. The number of eggs laid is very large - from 665 thousand to 4.1 million. The eggs are large, with a diameter of about 4 mm.

Kaluga is a typical predator. In the Amur estuary, during the run of Far Eastern salmon, it feeds on chum salmon and pink salmon; Due to the decline in salmon numbers, cases of cannibalism have now become more frequent. The food of the residential river form of Kaluga consists mainly of small bottom fish: minnows, killer whales.

Thanks to the long-term ban on sturgeon fishing in the Soviet part of the Amur basin, kaluga stocks are now gradually being restored and in 1976. Strictly limited fishing has begun in the estuary.

Beluga (Huso huso) distributed in the basins of the Caspian, Black and Azov seas; occasionally found in the Adriatic Sea, from where it enters the Po River. The Black Sea and Azov beluga are often divided into subspecies (Huso huso ponticus and Huso huso maeoticus). Unlike kaluga, beluga leads a migratory lifestyle.

Beluga is one of the most large fish found in fresh waters globe. In the last century and the beginning of this century, giant belugas were repeatedly caught - 4-5 m long, weighing 1 ton or more, age 65-70 years.

In 1922 A beluga weighing 1230 kg was caught near Astrakhan. During archaeological excavations of medieval settlements located on the Volga, bone remains of beluga sturgeons exceeding 6 m were found. The approximate mass of such fish apparently reached 1.5 tons. It is not surprising that the fight with such giants caught in the gear in the past often ended tragically for catchers.

Currently, the average harvest weight of beluga entering the Volga is 70 kg for males and 125 kg for females; in the Urals, the catches are dominated by males weighing 40–60 kg and females weighing 60–100 kg.

To breed, the beluga climbed very high in the rivers, higher than other sturgeon species. Along the Volga it reached Kalinin, and was found in many of its tributaries: the Kama, Vyatka, Oka, Samara, Sura, etc. The main spawning grounds were located in the area from Kamenniy Yar to the mouth of the Kama. A lot of beluga was caught in the Urals, where it was found as far as Orenburg. Of the rivers on the western coast of the Caspian, beluga was very numerous in the Kura, along which even in late XIX V. went up to Tbilisi. Azov Beluga in large quantities entered the Don, and was caught here almost along its entire length. The main spawning rivers of the Black Sea beluga were the Danube, Dnieper and Dniester. Along the Dnieper it rose early to Kyiv and entered its tributaries Styr, Pripyat, Sozh, Desna.

The course of the beluga into the rivers is quite extended. Like other migratory sturgeon species, it has spring and winter forms. The peak of the spring form usually occurs at the end of March - April; The winter season comes in September–November and winters in the river in pits. Both forms reproduce in late spring and summer, from May to July. In the Volga beluga the winter form predominates, in the Kura, on the contrary, the spring form, and in the Urals to the same degree both are presented.

Beluga, like kaluga, is a late-maturing fish. The majority of females going to spawn in the Volga reach 17–26 years of age, males – 14–23 years. The central part of the spawning population of the Ural beluga consists of females aged 21–28 years and males aged 15–19 years. Mature males of the Azov beluga are found at the age of 12–14 years, females – 16–18 years.

Beluga breeds in river beds, usually on rocky ground. Its fertility is very high, depending on the size of the females, it ranges from 224 thousand to 7.7 million eggs; The average fertility of the running Volga beluga is over 800 thousand eggs.

The regulation of the flow of most southern rivers caused severe damage to the natural reproduction of the beluga, as a result of which almost all of its spawning grounds were cut off. The population of this species is now entirely maintained through artificial breeding in fish hatcheries. From 1954 to 1977 About 200 million of its young were released into the Caspian Sea alone.

The young beluga does not stay in the river and migrates to the sea in the same summer. Beluga begins to eat fish very early. The basis of her diet is mass species: gobies, herring, sprat, anchovy, semi-anadromous carp (roach, ram). Even seal whites were found in the stomachs of the Caspian beluga. Recently, cases of beluga eating other sturgeon have become more frequent, which is apparently due to a decrease in the number of its main food items, primarily herring, gobies and roach. In 1952 On the Volga, under the leadership of Professor N.I. Nikolyukin, an intergeneric hybrid of beluga and sterlet, called bester, was bred under artificial conditions. This hybrid turned out to be prolific, is characterized by rapid growth and easily matures in ponds, which opens up prospects for its use as an object of commercial sturgeon breeding, as well as for breeding new pond forms of sturgeon fish on its basis.

The genus sturgeon (Acipenser) is the richest in species among sturgeons. There are only 17 of them, of which the range of nine species also covers the water bodies of the Soviet Union. All sturgeons have a small mouth, in the form of a transverse slit, and the gill membranes are attached to the intergill space.

According to the number of chromosomes, sturgeons fall into two groups: 120-chromosomal and 240-chromosomal species. The first group includes thorn, sterlet, stellate sturgeon, and Atlantic sturgeon; to the second - Russian, Siberian, Amur, Adriatic sturgeon. The karyotypes of other species, mainly found outside the USSR, have not yet been studied.

Quite a rare and small species in this genus - thorn (Acipenser nudiventris). It is easily distinguished from other sturgeons by its unbroken lower lip. This is a large migratory fish inhabiting the basins of the Caspian, Aral, Black and Azov seas. It is extremely rare in the Black and especially Azov Seas. The spike can reach a length of more than 2 m and a weight of 50 kg. The age limit is 36 years.

In the Caspian basin, the main river visited by the ship is currently the Ural; Previously, a lot of it entered the Kura and Sefidrud rivers. In the Volga, thorn has always been rare. It is interesting to note that Volga fishermen call all sturgeon hybrids thorns. For example, the sturgeon thorn is a hybrid between the thorn and sevruga, the sturgeon thorn is a cross between sterlet and Russian sturgeon.

In the Aral Sea, the thorn is represented mainly by the winter form, the entry of which into the Amu Darya and Syr Darya begins in April and continues until autumn (September–October). The length of the running spike in the Amu Darya reaches 143–175 cm and the weight is 19–31 kg. It lies in the river for the winter and spawns only the following spring, from March to May. The thorn breeds at water temperatures above 10°C in sections of the river with rocky rocks reaching the surface of the bottom, less often on hard clay soil. The development of eggs at a water temperature of 19.5°C lasts 5 days. The main spawning grounds in the Amu Darya were located between Chardzhou and Turtkul, in the Syrdarya - in the Chinaz region. Spawned fish and fry migrate to the sea that same summer, but some of the juveniles, apparently, can stay in the river for more than a year. In the last 10–15 years, as a result of irrigation hydraulic construction on the Amu Darya and Syr Darya, the Aral thorn has almost no spawning grounds left and it has become very popular here. rare fish.

In the Urals, the thorn, on the contrary, is represented only by the spring form, which goes into the river during April. The average length of a running Ural spike is 130–155 cm and weight is 12–19 kg. IN last years About 3.5–5 thousand producers enter the Urals. Spawned individuals appear in the river delta in mid-May. Juvenile Ural thornfish can stay in the river for up to 2–5 years, where a large number of them die from winter death or predators. This ecological feature of the thorn apparently explains its paucity in most water bodies.

The thorn first matures at the age of 12–14 years; males are 1–2 years earlier than females. Its fertility in the Aral Sea basin is 52–575 thousand eggs, of the Caspian thorn (Kura) – 280–1290 thousand eggs. Mature eggs have a diameter of about 3 mm. The main food of the thorn in the Aral and Caspian Sea is fish (gobies, silversides), as well as mollusks.

The smallest species in the genus Acipenser is sterlet (Acipenser ruthenus). Its lower lip, unlike the spine, is interrupted in the middle, and it differs from other sturgeons in the large number of lateral bugs (usually more than 50 of them) and fringed antennae.

Sterlet is very widespread, found in the rivers of the Black, Azov, Caspian and Baltic seas. At the end of the 18th – beginning of the 19th centuries. (possibly earlier) the sterlet penetrated from the Kama basin to the Northern Dvina through a system of canals. Found in the past in both Onega and Ladoga lakes. It is found in the large rivers of Siberia - the Ob, Irtysh and Yenisei, where it is represented by an independent subspecies - the Siberian sterlet (Acipenser ruthenus marsiglii). Further to the east (Pyasipa, Khatanga, Lena, Kolyma) it is absent. The main sterlet rivers are the Volga with its tributaries, the Don, the Ob and the Irtysh. Sterlet was transplanted into many reservoirs: Pechora, Western Dvina, Mezen, Neman, Amur, but it did not take root everywhere.

Sterlet is a typically freshwater fish, but in the Volga basin, a large semi-anadromous form is also found in small numbers ( average length females 74 cm and weight 2.8 kg), which feeds on the rich pastures of the Northern Caspian Sea, and rises low along the river to spawn. This form of sterlet was even isolated as an independent species (Acipeiiser primigenius). The existence of a large, semi-anadromous, fast-growing sterlet in the Volga (and, possibly, in our other southern rivers) is also confirmed by archaeological materials.

The usual commercial length of sterlet is 40–60 cm, weight 500–2000 g. As an exception, it reaches a length of 120 cm and a weight of 16 kg. Such a specimen was caught in 1849. on the Volga 100 km below Saratov. The sterlet is very variable in the shape of its snout; many researchers distinguish it into two forms: blunt-snouted and sharp-snouted. The blunt-snouted sterlet is characterized by faster growth, it is more plump and has greater fertility compared to the sharp-snouted sterlet. Sometimes the blunt-snouted sterlet is considered as a winter form, and the sharp-snouted sterlet as a spring form. Such morphological heterogeneity, expressed in differences in the special shape of the snout, is also characteristic of other sturgeon species closely associated with fresh waters - the Siberian and Amur sturgeon.

The biology of sterlet has been well studied. It winters in the river in pits, where it accumulates in large numbers; in spring, during high water, it rises upstream to spawning grounds. Sterlet breeds both in the riverbed and on rocky coastal ridges flooded by floods. The peak of spawning in the Middle Volga is in May. Males usually predominate on spawning grounds, each of which, apparently, participates in the insemination of eggs of several females. Sexual maturity in river conditions (Volga) for male sterlet occurred at 4–5 years, for females at 7–9 years. Fecundity fluctuates greatly, which is determined by the size of the females. The Volga sterlet lays from 4 to 140 thousand eggs, the Ob - from 6 to 45 thousand, the Irtysh - from 6 to 16 thousand. The eggs develop in about 4–5 days. The question of the frequency of sterlet spawning has not been fully clarified. Some researchers believe that sterlet spawns annually; others conclude that it breeds at intervals of 1–2 years.

After spawning, the sterlet is intensively fattened. Its food consists of small bottom invertebrates: larvae of chironomids, midges, mayflies, caddis flies, and mollusks. It also readily eats caviar laid by other fish, including anadromous sturgeon. During the summer of the mayfly, the sterlet rises to the surface, turns over with its belly up and collects insects that have fallen into the water with its mouth.

Runoff regulation had a very strong impact on the biology of sterlet. In reservoirs (for example, in Kuibyshevsky) it grows well, but does not mature well, and it has a significant percentage of fattened barn fish. In addition, the conditions of natural reproduction here are severely disrupted ( great depths, lack of flow and suitable soils for spawning). In the Kuibyshev Reservoir, most females mature only at 10–14 years of age. Spawning grounds here are preserved only in the uppermost areas, where there is a more or less pronounced current.

Therefore, it is so necessary to carry out work on a large scale to artificially breed sterlet and stock it with fish in various water bodies. It should be remembered that it was the sterlet that was the object among sturgeons, the breeding experiments of which laid the foundation for domestic sturgeon breeding, the centenary of which was celebrated in 1969.

This species is a traditional and long-standing object of pond cultivation. In 1971 near Moscow, for the first time, it was possible to obtain offspring from sterlet spawners raised in cages installed in a reservoir, and later eggs and juveniles were obtained from fish kept in a warm-water farm at a state district power station, which opens great prospects for the use of this valuable species in commercial sturgeon farming.

Stellate sturgeon (Acipenser stellatus) It stands out well among other sturgeons due to its exceptionally long sword-shaped snout, which accounts for more than 60% of the length of the head. Based on this characteristic, as well as a number of physiological and biochemical differences from other sturgeon species, some researchers propose to classify the stellate sturgeon into an independent genus Helops. Her antennae are quite short, without fringes. The lower lip is interrupted in the middle. Reaches a length of 220 cm and a weight of 80 kg.

Stellate sturgeon is an anadromous fish, common in the basins of the Caspian, Black and Azov seas. Found in small quantities in the Adriatic and Aegean seas. Forms local herds that gravitate towards certain rivers. The spawning grounds of stellate sturgeon are, as a rule, located below the spawning grounds of other anadromous sturgeon. In the past, it rose along the Volga to Rybinsk, entered the Oka and Kama; in the Urals it was found above Uralsk. A typical stellate river is the Kura, where previously, before the construction of the Mingachevir hydroelectric station, it reached the mouth of the Alazani. It also enters other Caspian rivers - Terek, Samur, Sulak, Astara, Sefidrud. In the Volga and at present, the sturgeon successfully breeds below Volgograd; Before the construction of the Volgograd hydroelectric power station, many fish traveled to Saratov to spawn. In the Urals, now the main stellate river, the main spawning grounds are located 300–400 km from the mouth, below the Inder Mountains. The Azov stellate sturgeon rises to spawn mainly in the Kuban, where it used to be found as far as Nevinnomyssk, and less so in the Don, along which at the beginning of the 20th century. reached the mouth of the Khopr. In the Kuban, before the regulation of its flow, the main spawning site for stellate sturgeon was the section of the river between the Tbilisskaya station and the city of Kropotkin. From the Black Sea, sturgeon goes to the Dnieper (it used to reach Kyiv), the Dniester, the Southern Bug, the Rioni, and the Danube.

It also forms seasonal races, but in most rivers the spring form predominates. Stellate sturgeon, unlike Russian sturgeon, prefers more fast rivers, and its mass entry into them occurs during the spring flood (April–May). Apparently, this explains that in recent years, due to the deformation of the spring flood on the Volga, a significant part of the sturgeon of Volga origin (up to 25–30%) goes to spawn in the Urals.

Among our migratory sturgeons, the stellate sturgeon is the most heat-loving fish, and therefore its spawning run into rivers usually occurs later and at higher water temperatures than that of beluga and Russian sturgeon (maximum spring run in the Volga at 10–14 ° C; autumn run - at 13–17°C).

Sevruga is an early ripening species. The bulk of males of the Volga herd reach sexual maturity at the age of 8–11 years, females at 10–14 years. The predominant age groups of the common Ural stellate sturgeon are 10–17 years old among males and 12–17 years old among females. Males of the Kura herd mature at the age of 11–13 years, females at 14–17 years. The Azov sturgeon is the fastest growing: males become sexually mature at 5–8 years, females at 8–12 years. It is also characterized by the fastest growth.

The average weight of running males on the Volga in recent years is 6–7 kg, females – 11–12 kg; In the Urals, male stellate sturgeon going to spawn have an average weight of 6 kg, females - 10 kg.

Spawning periods are quite extended: in the Volga - from May to August, in the Kura - from April to September, in the Kuban - from April to August, in the Don - from May to June. Spawning usually occurs at a water temperature of at least 18–19°C.

The fertility of stellate sturgeon in different rivers varies greatly: in the Volga - from 92 to 633 thousand eggs, in the Ural - from 19 to 743 thousand, in the Kurinsk - from 35 to 360 thousand, in the Kuban - from 150 to 380 thousand.

After spawning, the stellate sturgeon does not linger in the river, but immediately slides into the sea to its feeding grounds. Most of all, in recent years, it has been found along the western coast of the Caspian Sea, in the area from the Agrakhan Spit to the Absheron Peninsula. In spring, stellate sturgeon begins to move north and is gradually distributed throughout the entire water area of ​​the Northern Caspian Sea.

The main food of stellate sturgeon in the Caspian Sea is now the multichaete worm Nereis, acclimatized here in the late 30s, as well as crustaceans. The Azov sturgeon feeds on worms and small fish (gobies, anchovy).

Stellate sturgeon takes first place in the sturgeon fishery. The bulk of it is mined in the Urals.

Among the very large anadromous sturgeons is Atlantic sturgeon (Acipenser sturio). It is characterized by massive bugs, the surface of which is radially striated. In addition, there is a very strong bony ray in the pectoral fin. Reaches a length of 3 m and a weight of more than 200 kg.

The Atlantic sturgeon can serve as a sad example of how a once widespread and numerous species could not withstand human influence and in a short time almost disappeared from the fauna of our planet. Back in the middle of the 19th century. this sturgeon was a commercial fish both off the coast of Europe and North America. It was found in the basins of the Baltic, Northern, Mediterranean and Black Seas, off the coast of France, Spain, North Africa. It entered many rivers in Europe: the Rhine, Elbe, Oder, Vistula, Loire, Garonne, Seine, etc. It was distributed along the American shores of the Atlantic from Florida to Hudson Bay. Its catches began to fall catastrophically at the turn of the 19th and 20th centuries, by the middle of this century in rivers Western Europe and North America it has practically disappeared. Back in the 30s, it entered the Neva from the Baltic Sea, ascended it to Lake Ladoga, from where it entered Volkhov, Svir, and Syas to spawn. Perhaps there was also a residential form of this sturgeon in Lake Ladoga. In 1953 There was a case of catching an Atlantic sturgeon in the White Sea.

Currently, a small population of this sturgeon, apparently numbering no more than 1000 adult fish, has survived only in the Black Sea, in the Rioni River basin in the Caucasus. Single individuals are also found in the Danube and Po.

Sturgeon enters Rioni from late April to June. There is no autumn move here. The age of males going to spawn is at least 7–9 years, females are at least 8–14 years old. The average size of running males is 137cm, females 182cm. The Rioni hydroelectric power station did not affect its main spawning grounds, which are located 120–130 km from the mouth. The height of spawning occurs in the second half of May. The fertility of females ranges from 200 thousand to 5.7 million eggs. After spawning, the sturgeon quickly slides into the sea. In the Black Sea it feeds mainly on anchovy.

Atlantic sturgeon is of exceptional value. It is characterized by a very high growth rate, significantly surpassing other sturgeon in this indicator. This species is included in the second edition of the Red Book of the USSR. For its artificial breeding, a fish factory was built on Rioni.

In many ways it is close to the Atlantic sturgeon Pacific, or Sakhalin, sturgeon (Acipenser medirostris), but its bony ray in the pectoral fin is much less developed. In the Pacific Ocean it is widespread, but very rare. Along the Asian coast it is found from the Amur estuary to Korea, in the rivers of Sakhalin and Primorye, off the coast of Hokkaido. Discovered in Olyutorsky Bay of the Bering Sea. Along the American coast it is known from San Francisco to the Columbia River.

Its biology has been studied extremely poorly. Reaches a length of more than 2 m, a weight of 60 kg. Leads a casual lifestyle. In our waters for spawning it enters small rivers flowing into the Tatar Strait (Tumnin River), into the Tym River on Sakhalin, and also, possibly, into tributaries of the Amur Estuary. Presented as a winter form. Goes to spawn late autumn, winters in the river and spawns on next year, in June–July. Spawning grounds are unknown. It feeds on bottom invertebrates and small fish. Also included in the Red Book of the USSR.

The central place in terms of numbers among sturgeons proper is occupied by Russian sturgeon (A. guldenstadti). It differs from other species in its short, blunt snout and the location of its antennae, which sit closer to the end of the snout than to the mouth. The antennae are without fringes, the lower lip is interrupted. Reaches a length of 230 cm and a weight of 80–100 kg.

Its range almost coincides with the ranges of beluga and stellate sturgeon. These are the basins of the Caspian, Black and Azov seas. Russian sturgeon also forms local herds, linked by breeding to individual rivers (Volga-Caspian, Ural-Caspian, Kurin, Dnieper, Danube, etc.).

In the rivers, sturgeon used to rise very high, much higher than stellate sturgeon. The main sturgeon river in the Caspian Sea is the Volga, along which it was known almost to the upper reaches (Rzhev), as well as in the Oka, Klyazma, Sheksna, Vetluga, Kama, Vyatka. In the 18th century met, apparently, even in the Moscow River, as mentioned by K. Roulier: “... around 1740 they came from the Oka to the Moscow River to Stone Bridge even sturgeons, which no one remembers today..." The main spawning grounds were located between Volgograd and Saratov. Many sturgeon enter the Urals, along which they climbed to the mouth of the Sakmara. They also go to spawn in other rivers of the Caspian Sea: Kuru, Terek, Sulak, Samur In the pool Sea of ​​Azov it was most numerous in the Don, along which it rose to Zadonsk; significantly less in Kuban. The most important spawning rivers in the Black Sea are the Dnieper, where it previously rose to Dorogobuzh, the Danube, the Dniester, the Southern Bug, and the Rioni. As a result of flow regulation, most of the sturgeon spawning grounds were cut off.

In addition to the anadromous form, in the upper and middle sections of large rivers (Volga, Ural) there was also a residential form that constantly lived in fresh water, characterized by its smaller size and slower growth.

The course of sturgeon in rivers is very extended; it forms winter and spring forms. The sturgeon of the Volga-Caspian stock is most difficult to differentiate, in which early spring sturgeon are distinguished (maximum run from March to May at a water temperature of 4–8 ° C), late spring sturgeon (run in May–June at a water temperature of 16–22 ° C), winter sturgeon on the summer run (second half of May – July at a temperature of 18–24 °C) and winter sturgeon on the autumn run (from August to October at a temperature of 24–8 °C). Sturgeons of different biological groups differ in size, length of migration, degree of gonad maturity, duration of stay in fresh water and other indicators. Spawning of Volga sturgeon of all biological groups (except for late spring sturgeon) occurs during May at water temperatures from 9 to 16 °C.

The spawning population of the Ural sturgeon also has a complex structure, in which the mass movement of the spring form into the river is observed from the second half of April to mid-May, and the winter form - from late June to mid-August.

In general, in the Volga and Urals, as studies have shown, winter groups of sturgeon predominate.

On the contrary, in the rivers of the Azov-Black Sea basin, sturgeon is mainly represented by the spring form. In the past, its mass movement in the Don was observed from April to May; a weak rise (winter form) was observed in September–November. Approximately the same picture was observed in the Dnieper. The Kuban sturgeon, apparently, is represented entirely by the spring form, which entered the river in April–May and immediately reproduced.

The average weight of the running sturgeon on the Volga in 1977. was 21.2 kg (females) and 13.7 kg (males); in the Don, before the construction of the Tsimlyansk dam (1952), female sturgeon had an average weight of 26–27 kg and males 11–13 kg; in the Urals this figure for fish of both sexes in 1974. was equal to approximately 14.8 kg.

In the Northern Caspian Sea, male sturgeon reach sexual maturity no earlier than 12–13 years and females 15–16 years. The Azov sturgeon becomes sexually mature somewhat earlier: males at the age of 8–11 years, females at 11–15 years. Mass maturation of males of the Danube sturgeon stock occurs at 13 years, females at 15 years.

The fertility of Russian sturgeon varies within very wide limits - from 60 to 880 thousand eggs, averaging about 250-300 thousand eggs. After hatching, the young sturgeon roll into the sea that same summer, but some can remain in the river for up to 1–2 years.

The favorite food of sturgeon in sea pastures is shellfish. It also eats shrimp, crabs, and the Nereis worm. Fish (gobies, anchovy, sprat) are its secondary food. In the total production of sturgeon in the 70s, it took second place (after stellate sturgeon).

Recently, many researchers have identified Persian, or South Caspian, sturgeon (Acipenser persicus). It was first described at the end of the last century, but then was considered as a subspecies of Russian sturgeon (Southern Caspian) or as one of its intraspecific biological groups (Northern Caspian), the so-called late spring, or summer-spawning, sturgeon. It differs quite sharply from the Russian sturgeon in having a slightly lowered, massive, long snout, a smaller number of bugs in all rows, and also a gray-bluish color of the back. There are no less profound differences in a number of other morphological and physiological-biochemical parameters. The Persian sturgeon is on average much larger than the Russian one. In 1973 on the Volga, the weight of a female Persian sturgeon averaged 28 kg, while the weight of a female winter form of Russian sturgeon was 19 kg; male Persian sturgeon are almost twice as heavy as male Russian sturgeon (19 and 11 kg, respectively). To spawn, it enters the same rivers as the Russian sturgeon, but gravitates more towards the southern regions of the sea. The main spawning river for it was the Kura, but in recent years quite a lot of this sturgeon goes to the Volga and Ural. The Persian sturgeon rises low and reproduces in the same year when it enters the river. Spawning in summer, later than for Russian sturgeon, in July–August, at a water temperature of 20–22 °C. Fertility - from 84 to 837 thousand eggs (in Kura). The Persian sturgeon is of great interest as an object of fish farming.

In addition to sterlet, another representative of sturgeon lives in the rivers of Siberia - Siberian sturgeon (Acipenser baeri). But its range here is much wider. In addition to the Ob basin with the Irtysh and Yenisei, it is found further east, to Kolyma, and also in Lake Baikal. The sturgeon that lives in the rivers of Eastern Siberia (Lena, Olenek, Yana, Indigirka, Kolyma) is classified into a special subspecies - the Yakut sterlet-shaped sturgeon, or hatys (Acipenser baeri hatys). The Siberian sturgeon is easily distinguished from the sterlet by a smaller number of lateral bugs (no more than 50), and from the Russian sturgeon, to which it is close, by fan-shaped gill rakers and a more pointed snout. However, the shape of its snout, like that of the sterlet, varies greatly, and along with sharp-snouted specimens, blunt-snouted ones are also found in the same place.

Its dimensions vary in different pools. In the Ob and Baikal, sturgeon weighing 180–200 kg were found, in the Yenisei – up to 100 kg, in the Lena – up to 60 kg. The average fishing weight of Ob sturgeon is 15–16 kg, Yenisei sturgeon – 4–6 kg, Lena sturgeon – 2–3 kg.

Siberian sturgeon is a semi-anadromous fish. It feeds in the estuaries of Siberian rivers, and for reproduction it ascends many hundreds of kilometers along them: along the Ob, before the construction of the Novosibirsk hydroelectric power station, 2500 km, along the Yenisei 1500 km, along the Lena 500–700 km. This migration continues for more than a year and is interrupted by wintering in the river on pits (winter race). In addition to the migratory form, in most rivers it also has residential, sedentary groups. There are observations that mature semi-anadromous sturgeon, rising to the spawning grounds, are colored gray, smoky, and residential sturgeon are brownish-brown. The same differences in the color of these two forms were noted in the Amur sturgeon.

The Siberian sturgeon lives in very harsh conditions, grows slower than Russian sturgeon and matures late: males no earlier than 15–18 years, females at 18–20 years. The Lena sturgeon is more precocious, reaching sexual maturity earlier (males at 11–13 years, females at 13–15 years), while having very small, “sterlet” dimensions (length about 70 cm and weight 1.5–2 kg ).

Several thousand years ago, the Siberian sturgeon entered Baikal (possibly from the Yenisei basin through the lower Angara) and formed here a unique lake-river form, which feeds in the coastal zone of this lake (to depths of 150–200 m), and breeds in large tributaries ( Selenga, Barguzin, Upper Angara). The main spawning river is the Selenga, along which it rises 1000 km.

In the rivers of Siberia, sturgeon breed in the summer, in June–July; Baikal - a little earlier, at the end of May - the first half of June. Its fertility varies in different reservoirs: in the Ob - from 174 to 420 thousand eggs, in the Yenisei - from 79 to 250 thousand, in the Lena - from 16 to 110 thousand.

Its food consists of a variety of bottom organisms: larvae of chironomids, caddis flies, mayflies, amphipods, gammarids, worms, mollusks, and less often fish. In winter, under the ice, it does not stop feeding.

All Siberian sturgeons are of great interest for acclimatization and fish breeding work. They are promising for stocking large reservoirs and lakes, as well as in commercial sturgeon farming, especially in warm waters.

Siberian sturgeon is very unpretentious and has great growth potential. Lena sturgeon grown in warm-water farms at state regional power plants grows 7–9 times faster than in natural conditions. In 1981 at the Konakovskaya State District Power Plant, near Moscow, for the first time it was possible to obtain offspring from him: in the pools, females matured at the age of 8 years, males at 4 years (i.e., much earlier than on the Lena).

Very close to Siberian Amur sturgeon (Acipenser schrencki), from which it differs in the shape of its gill rakers: they are not fan-shaped, but single-pointed, smooth. It is likely that the Amur sturgeon is only a subspecies of the Siberian sturgeon. It is widespread in the Amur basin, from the estuary to Shilka and Argun. Forms semi-anadromous and residential forms; the latter is represented by a number of local herds. Length up to 2 m, weight up to 56 kg (in the past up to 160 kg). Males reach sexual maturity at 10–13 years, females at 11–14 years. Spawning in the Amur riverbed occurs in May–June. The main spawning grounds are above Nikolaevsk-on-Amur. Fertility – from 29 to 434 thousand eggs. By the nature of its diet, the Amur sturgeon is a typical benthophage.

In addition to the reservoirs of the USSR, a number of sturgeon species are found in other areas of the northern hemisphere. The Adriatic Sea is inhabited in small quantities by the migratory Adriatic sturgeon (Acipenser naccarii), which enters the Po River. Into the rivers Atlantic coast In North America, the blunt-nosed sturgeon (Acipenser brevirostris) comes to spawn. Along the American coast Pacific Ocean From Alaska to California, very large white sturgeon (Acipenser transmontanus) are found. In North America, in the Great Lakes and basins of the Mississippi and St. Lawrence, the freshwater lake, or brown, sturgeon (Acipenser fulvescens), very similar in biology to the Baikal sturgeon, lives. Two species of Japanese anadromous sturgeon (Acipenser kikuchii and Acipenser multiscutatus) are found in the waters of the southern Sea of ​​Japan. There are two species of Chinese sturgeon (Acipenser sinensis and Acipenser dabrianus) found in China (Yangtze). All these species, with the exception of the American lake sturgeon, are very rare and have no commercial significance.

The subfamily of shovelnose fish (Scaphirhynchinae) includes very peculiar fish, well adapted to living in fast flowing water carrying a large amount of suspended matter. The eyes of shovelnose snakes are very small, often almost completely covered with skin, and vision big role does not play in the life of these fish. But the sense of touch is well developed, the organs of which are the long antennae and, apparently, the entire lower surface of the snout. Large bony bugs, forming a kind of shell, provide good protection from mechanical damage and solid particles carried by the flow. The flat, spade-shaped snout serves to hold the fish in a fast current: a stream of water flowing over it presses the fish to the bottom.

Shovelnoses distributed in two regions of the globe: the genus American shovelnose (Scaphirhynchus) is found in the Mississippi basin, the genus of pseudoscaphirhynchus (Pseudoscaphirhynchus) is found in the Amu Darya and Syr Darya basin. Central Asian shovelnose fish differ from American shovelnose fish by a shorter caudal peduncle, not entirely covered with scutes, and a reduced swim bladder (in American shovelnose fish it is well developed).

There are two species in the American shovelnose genus: common shovelnose (Scaphirhynchus platorhynchus), having a length of up to 90 cm, and significantly more common white shovelnose (Scaphirhynchus albus), the length of which can reach 1 m.

Both species are typical river fish, with the white shovelnose living in the faster current (lower Missouri). They breed in spring and summer and enter tributaries with rocky soil to spawn. They feed mainly on aquatic insect larvae. The common shovelnose fish used to be an important fishery target. Now the numbers of both species have sharply declined.

Central Asian shovelnoses are represented by three species, two of which – the large pseudoscaphirhynchus kaufmanni) and the small pseudoscaphirhynchus hermanni – are found in the Amu Darya and one species, the Fedchenko pseudoscaphirhynchus (Pseudoscaphirhynchus fedtschenkoi) – in the Syrdarya. The last two species have always been very rare. They became known to science quite recently, at the end of the last century. Found the Syrdarya shovelnose in 1871. The outstanding Russian geographer and traveler A.P. Fedchenko discovered the large Amu Darya shovelnose in 1874. the famous naturalist M.N. Bogdanov, and the small shovelnose in 1870. discovered in the Amu Darya by zoogographer Academician N.A. Severtsov.

Shovelnoses inhabit the lowland areas of these rivers, from the seashore to the foothills. They do not go into the salty water of the Aral Sea. The size of Central Asian shovelnose snakes is small. The largest of them - the large Amudarya - reaches a length of 58 cm and a weight of 760 g (as an exception, in the past there were specimens weighing up to 2 kg). The small shovelnose is much smaller, up to 27 cm; the Syr Darya shovelnose, similar to it, has the same dimensions.

Shovelnoses are typical inhabitants of the riverbed. They live on sandy and pebble shallows and in channels. To hold on to a fast current, in addition to the wide and flat snout, the small and Syrdarya shovelnose fish have a peculiar folded shape of pectoral fins, which play the role of suckers. In the large Amu Darya shovelnose (and some specimens of the Syrdarya one), the upper lobe of the caudal fin is elongated into a long thread, apparently performing the function of a balancer. At the end of the snout of a large shovelnose there are from 1 to 9 sharp spines, which probably play important role when breeding in fast currents.

Shovelers breed on coarse sandbanks and rocky placers in the river bed at shallow depths (1.5–2 m). Spawning occurs in early spring, in March–April, at a water temperature of 14–16 °C. The female large shovelnose lays up to 15 thousand eggs, but usually no more than 2 thousand; the Syrdarya shoveler sweeps up to 1.5 thousand eggs; The fecundity of the small shovelnose bat is unknown. They reach sexual maturity at the age of 6–7 years; Males usually mature a year earlier than females. In addition to the usual form, the large shovelnose is described as having a stunted dwarf form, which matures at a length of 23–24 cm and a weight of only 39–40 g.

The favorite food of shovelers is small bottom invertebrates (larvae of chironomids, caddis flies, mayflies), as well as fish eggs. The large shovelnose also feeds on larger prey (barbel fry, saberfish, loaches, and spearfish).

Indigenous population on the Amu Darya for a long time did not eat the large shovelnose as food because of its long “tail”, reminiscent of a mouse or snake (hence the local name for this fish - mousetail or snaketail). The Ural Cossacks, who moved to the Amu Darya at the end of the last century, began catching shovelnose fish. The meat of these fish tastes like sterlet.

Currently, due to a sudden change water regime As a result of irrigation and hydro-construction of the Amu Darya and Syr Darya, there are almost no places left suitable for their reproduction. Many juvenile shovelnose fish die under the scorching rays of the sun, falling through water intake structures into irrigation systems. The number of these fish is now very small, and all three species of Central Asian shovelnose fish are included in the Red Book of the USSR.

general characteristics

Sturgeon are quite large fish (beluga reaches a length of 9 m). The body is elongated, almost valval.

The sturgeon family belongs to the group of cartilaginous ganoids. There are 5 longitudinal rows of bone scutes on the body - bug; the muzzle is elongated, almost spatulate or conical, with a small transverse toothless mouth; which lies on the underside of the head and can be pulled out; on the underside of the muzzle, in front of the mouth, there are 4 antennae arranged in a transverse row; vertical fins in front with one row of fulcra (see Ganoid); the dorsal and anal fins are close to the caudal fin; gill membranes merge at the throat and are attached to the pharynx; no gill rays; 4 gills, there are also 2 accessory gills; The swim bladder is large, simple, and communicates with the dorsal side of the esophagus.

Lifestyle

All sturgeon fish are either anadromous or freshwater; To spawn, migratory species, as well as those living in lakes, enter rivers. Sturgeon fish V highest degree are fertile and the number of testicles in large individuals is estimated at several million. In addition to entering rivers in the spring for spawning, sturgeon fish sometimes enter rivers in the fall for wintering. These fish stay mainly at the bottom and feed on various animal foods: fish, shellfish, worms, insects.

Commercial significance

Black caviar in a glass

Sturgeon fish (specifically representatives of the genus sturgeon - Acipenser) are of great commercial importance; they were originally called red fish - for their special value. Their meat is highly valued; the famous black caviar is an even more valuable product; In addition, the swim bladder provides valuable glue; the dorsal string is used as food under the name vyazigi.

Currently, industrial sturgeon fishing is carried out only in the rivers of the Caspian Sea - the Volga and Ural deltas, as well as in Iran. Annually international organization CITES determines catch quotas for each of the Caspian Sea countries. The size of the quota directly depends on the number of sturgeon fry released from special coastal fish hatcheries into the Caspian Sea.

With quota reductions and periodic complete trade bans becoming increasingly important, industrial sturgeon farming in fish farms around the world is likely to become the main source of precious black caviar on the market in the future.

Origin

In fossil form, oster fish have been known only since the Eocene. From a zoogeographical point of view, the representatives of the subfamily Scaphirhynchinae are very interesting, which are found on the one hand in Central Asia, on the other in North America, which makes us see modern types This genus is the remains of a formerly widespread fauna.

Taxonomy

Sterlet

The encyclopedia of the early 20th century - ESBE - classifies sturgeons as belonging to the order (or subclass) of ganoids (Ganoidei), suborder (or order) Chondrostei. Modern taxonomy classifies sturgeons into the order Sturgeons from the class of ray-finned fish.

Kinds

In the older classification, only two genera were distinguished: sturgeon ( Acipenser) and scafirhynchus ( Scaphirhynchus), containing only about 25 species, found exclusively in the temperate zone of the northern hemisphere: in Europe, Asia and North America.

Modern taxonomy distinguishes 4 genera in two subfamilies - Acipenserinae and Scaphirhynchinae. Four species belong to the subfamily Scaphirhynchinae, the rest to Acipenserinae. This includes 2 species of European sturgeon, sturgeon from Siberia and China, several species of sturgeon from the North. America, beluga, sterlet, stellate sturgeon, thorn. This includes mainly large fish.

Links

• Sturgeon- article from the Great Soviet Encyclopedia

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See what “Sturgeon fish” is in other dictionaries:

- (Acipenseridae), a family of fish of the order Sturgeon (see STURGEONATE FISH), superorder of cartilaginous ganoids; includes four genera (beluga, sturgeon, shovelnose and pseudoshovel), 23 species. The length of sturgeon is up to 9 m, weight up to 1.5 tons. They are characterized by... ... encyclopedic Dictionary

- (Acipenseridae) a family of fish from the order (other subclass) ganoids (Ganoidei; see), suborder (other order) Chondrostei. They are characterized by the following features: the body is elongated, almost valval, with 5 longitudinal rows of bones... ... Encyclopedic Dictionary F.A. Brockhaus and I.A. Efron

American Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus) ... Wikipedia

Fish (Acipeuseridae) is a family of fish from the order (other subclass) ganoids (Ganoidei), suborder (other order) Chondrostei. They are characterized by the following features: the body is elongated, almost valval, with 5 longitudinal rows of bones... ... Encyclopedia of Brockhaus and Efron

FISH- are lower vertebrates that live in water. They belong to two classes of the vertebrate subphylum (Vertebrata) of the chordate type (Chordata) Marsipobranchii and Pisces. The first group includes cyclostomes (Cyclosto mata) lampreys and hagfishes, the second group... ... Great Medical Encyclopedia

- (Acipenseridae), family of fish neg. sturgeon. Anadromous, semi-anadromous and freshwater fish. There are five rows of bone bugs along the body. The anterior ray of the pectoral fins is in the form of a thick spine. There are 4 antennae in front of the mouth. 4 genera: beluga, sturgeon, shovelnose and... Biological encyclopedic dictionary

Fish, aquatic vertebrates with variable body temperature; they breathe with gills, non-five-fingered limbs, usually in the form of fins. 2 classes: cyclostomes and R. proper. R. proper (Pisces) include 7 subclasses: acanthodes, arthrodires and winged R... Great Soviet Encyclopedia

Sturgeon- Sturgeon: 1 beluga; 2 Siberian sturgeon; 3 spike; 4 stellate sturgeon. STURGEONS, a family of valuable commercial fish. Length up to 9 m, weight up to 1.5 tons. 24 species, including thorn, sterlet, stellate sturgeon, Russian and Siberian sturgeon, beluga. Migratory and freshwater fish... ...

STURGEON- STURGEON. Sturgeon include sturgeon, beluga, thorn, kaluga, stellate sturgeon and sterlet, extremely valuable fish, dishes and snacks from which are characteristic feature Russian cooking. The sturgeon's body is covered with five rows of large bony scales,... ... Concise Encyclopedia household

Fish- fresh waters of Russia: 1 chub 2 ruff; 3 asp; 4 crucian carp; 5 carp; 6 rudd; 7 bream; 8 tench; 9 burbot; 10 perch; 11 minnow; 12 roach. FISH, aquatic vertebrates. Known since the Devonian. They breathe through gills, with limbs in the form of fins that serve... Illustrated Encyclopedic Dictionary

Books

• Commercial fish of the USSR. Descriptions of fish (text for the atlas of color drawings of fish). Moscow, 1949. Pishchepromizdat. With illustrations. Publisher's binding. The condition is good. It contains basic information on the biology and fisheries of the former USSR. This building serves…