Sturgeon fish live in salty sea waters and spawn in fresh water bodies. Representatives of the species are found in various sizes. Small fish (sterlet and others) grow up to 100 centimeters and weigh up to 15 kilograms. The largest sturgeon is the beluga. The weight of the largest fish caught was 1580 kilograms, the body length with head was 7.8 meters. The lifespan of the species is 120 years. There are many large sturgeon fish in the world. They are of great value because they bear black, delicious caviar.
Kaluga
Belongs to the sturgeon family. The body of the fish reaches 6 meters in length, weight - 1200 kg. It is found in the Amur basin, near Hokkaido, Kamchatka, and Sakhalin. Kaluga is the pride of Russia. Due to the rapid decline in numbers, it is listed in the Red Book. Environmental pollution and uncontrolled poaching are the main factors influencing the population decline.
The body of the kaluga is elongated, covered with bone plates in five rows with pointed spines. The triangular head is covered with thick leather. The mouth is large and transverse. At the bottom there are flattened antennae. The back and upper part of the head of the fish are green, the belly is white. In size, kaluga is second only to beluga. This colorful representative of the Far East is interesting to ichthyologists for its unique habits and behavior:
- Participate in spawning once every five years;
- Females are ready to breed at 17 years of age, laying up to 1.5 million eggs at a time;
- The adult feeds by sucking in prey. The fish opens its toothless mouth and draws in the victim along with the water like a pump;
- Kaluga is not picky about food. It feeds on bony, spiny fish covered in poisonous mucus.
Lives in the Azov and Caspian seas. It is found on the passage in the Ural, Kama, and Volga rivers. Grows up to 100 kilograms, 2.5 meters long. The Russian sturgeon has a spindle-shaped body, a large pointed head, and a blunt muzzle. The tactile organ of the fish - skin processes (antennae) - are located at the end of the snout. With them, the sturgeon probes the bottom in search of food. The skeleton consists entirely of cartilage, like other representatives of sturgeon.
The body of the Russian sturgeon species is not covered with scales, but with bony plates. Natural armor protects the predator from damage. Representatives of the family lead a benthic life. They reach sexual maturity at eight years of age. They interbreed freely with sterlet, stellate sturgeon, and beluga. The female spawns 2-3 times in her life at intervals of 5 years. The Russian sturgeon lives 50 years.
Since 1996, fish in Russia have been listed in the Red Book. It was decided to save the population due to many years of uncontrolled fishing. Black caviar remains an expensive delicacy. World exporters of the most valuable product are Turkmenistan, Russia, Azerbaijan, Kazakhstan, Iran.
A distinctive feature of the stellate sturgeon is its unusually long nose, similar in shape to a dagger. The forehead is convex, the antennae are flattened and elongated, do not reach the mouth, and the lower lip is not developed. Body weight and length vary depending on habitat. Fish can grow up to 2 meters and weigh 80 kilograms. The maximum recorded age of the fish is 41 years.
The stellate sturgeon lives in the salty seas - the Black and Caspian. To reproduce, it migrates to adjacent rivers. The body color of the fish is brown-black, the belly is white. It prefers to live and hunt at a depth of 100-300 meters, in the Caspian Sea - 3-15 meters. Azov stellate sturgeon is considered by fishermen to be a separate species. It feeds on small fish, mysids, and amphipods. The Caspian inhabitant of the sturgeon family eats polychaete worms acclimatized in the region.
In the fishery, stellate sturgeon ranks second after Russian sturgeon. Most of it is mined in the Urals. Fishing takes place in the spring with floating nets. The number of fish of this species is significantly higher than the number of other sturgeons. This is explained by the peculiarity of spawning. The stellate sturgeon does not rise high to lay eggs and quickly goes to sea.
The giant fish lives in European rivers and seas. It was spotted twice on Russian territory - in the White Sea at the mouth of the Umba and in the Kaliningrad region in the Baltic Sea. The fish grows up to 6 meters in length and weighs 180 kilograms. The species is adapted to life in salty and fresh water. The narrow and long body structure and enlarged caudal fin allow the underwater predator to quickly move at depth in search of food.
Deep-sea areas are preferable for representatives of the sturgeon species. At the bottom they feed on crustaceans and bottom mollusks. The lifespan of a sturgeon is 100 years. Males become sexually mature at 11 years of age. Females are ready to bear offspring at 18 years of age. Migratory fish migrate upstream every two years to reproduce and lay eggs in areas with pebbles. After two weeks, the fry appear, and after 2 years they begin their journey to the sea. Along the way, they become prey for other fish. The development of sturgeon from caviar to adult fish occurs in stages:
- In the spring, the female attaches 2.5 million eggs to river rocks;
- After 10-14 days, the fry appear;
- Larvae measuring 9 mm have a rudimentary tail;
- Week-old fry feed on reserves of the yolk sac;
- After 6-8 months, the fry develop a mouth and antennae;
- An adult fish stays in fresh water for two years, then goes to the open sea.
Thorn
Representatives of the species inhabit the Caspian and Aral seas. Rarely seen in the Azov and Black Seas. Migratory fish wait out the winter cold at the bottom of the Ural River. The main difference between the thorn fish and other sturgeons is the undivided structure of the lower lip. Protective bony plates cover the body of the fish. The color of the body is gray-green, the belly is light yellow. Adult fish grow up to 2 meters in length and weigh up to 20 kilograms.
The thorn is a sedentary fish. As it moves, it muddies the water with its fins. Adapts to the environment. It can stay in fresh waters for a long time and interbreed with other representatives of sturgeon. Lives in the natural environment for 20 years.
Sexual maturity occurs in thorn fish by the 12th year of life. Fertility within 1 million eggs. It rises up the river in mid-spring to spawn. The female attaches the eggs to pebbles at depth.
Belongs to the order Sturgeon, a species of ray-finned fish. Found in America Gulf of Mexico. The only representative of sturgeon that feeds on phytoplankton and zooplankton simultaneously. A characteristic feature of paddlefish is their constantly open mouth. Fish swim in such a state that they can take plankton and small fish into their mouths with water. The water is filtered through the gills, and the caught food enters the stomach.
The body of the fish has no scales. The average length is two meters, weight is 85 kilograms. The third part of the body is occupied by a paddle-shaped head, on which there is a pair of antennae. The only fin on the back is shifted towards the tail, located above the anal fin. The body color of the paddlefish is dark gray, the belly is silver.
This species of sturgeon has been bred in Russia since the 70s. Adult individuals were imported from America and placed in artificial fresh water bodies. Several hundred young paddlefish were released into the Krasnodar and Voronezh reservoirs. The fish is unpretentious in breeding and grows quickly. Feels great in ponds with an area of 70 hectares at a water temperature of 25 degrees. A prerequisite is the presence of silt and vegetation at the bottom.
It lives in wide, deep-water rivers flowing into the Laptev Sea, East Siberian, Kara Seas and Lake Baikal. Siberian sturgeon is divided into subspecies. Lives as a sedentary or migrates to spawn. The body length of an adult fish is within 3 meters, weight - 30 kilograms. Based on the shape of the muzzle, sturgeons are distinguished between blunt-snouted and sharp-snouted sturgeons. The mouth of both species is located under the head and is adapted for eating bottom invertebrates.
The Siberian sturgeon is slowly developing and growing. Males become capable of giving birth to offspring at the age of 10, females at 12 years. Fish spawn once every five years and do not leave fresh water. They lay eggs in places with coarse-grained soil and fast currents. Siberian sturgeons do not like sunlight, therefore they prefer to be at the depth of the reservoir.
A distinctive feature of the sterlet is its broken lower lip. The size of an adult animal is 1.5 meters and weighs 16 kilograms. The sturgeon species lives in Siberia in the Yenisei basin. Sterlet has commercial value.
Representatives of the species do not live alone; they move together throughout the reservoir. In winter, they lie on the bottom in one place. Hundreds of fish, closely pressed together, can wait out the cold in the recess. In the photo, a sterlet in its natural habitat is presented in a pair or group. The sociable nature of the fish encourages poachers to fish with nets.
Ichthyologists consider sturgeon fish to be one of the most ancient fish on Earth. Representatives of these species swam in rivers when dinosaurs still roamed the earth. Sturgeon meat – useful product. After cooking, less than 14% of inedible parts remain. A special delicacy is black caviar. The product is valued for its nutritional properties and the rare spawning of sturgeon.
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. Sturgeon are fish with a long 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. Participates in spawning big number age groups of producers. All sturgeons lay eggs in rivers, in areas with pebble or pebble-sandy soil, on fast current, in conditions of good oxygen supply. IN marine environment or in stagnant freshwater bodies of water, spawning does not occur. 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. Incubation period 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 the deltaic and pre-estuary spaces of large rivers (Ob, Yenisei, Lena, Amur), and in the spring they rise up them to spawn.
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, discovered even smaller biological groups in some species of sturgeon (Russian sturgeon, stellate sturgeon, beluga) within the winter and spring races, 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) They differ well from the sturgeon proper (subfamily Acipenserinae) by a very wide, flattened snout with sharp edges, as well as the absence or weak development of the squirter.
The largest sturgeon fish are beluga and kaluga (genus Huso), distinctive features which are a large 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 largest fish found in the fresh waters of the 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 Sea, beluga was very numerous in the Kura, along which at the end of the 19th century. 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 both are equally represented.
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 number of this species is now entirely supported by 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 its diet consists of common 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 hydro-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 (the average length of females is 74 cm and weight is 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 large semi-anadromous fast-growing sterlet in the Volga (and, possibly, in our other southern rivers) is 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. Puberty at river conditions(Volga) in male sterlet it occurred at 4–5 years, in 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 for natural reproduction here are severely disrupted (great depths, lack of flow and suitable soil 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 caviar and juveniles were obtained from fish kept in a warm-water farm at the State District Power Plant, which opens up 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. It is 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 passers-by sturgeon stellate sturgeon- the most heat-loving fish, and therefore its spawning run into rivers usually occurs later and at more high temperatures water 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 turn of the 19th century and XX centuries, by the middle of this century it had practically disappeared in the rivers of Western Europe and North America. 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 the 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 apparently found even in the Moscow River, as mentioned by K. Roulier: "... around 1740, even sturgeons came from the Oka River to the Moscow River to the Stone Bridge, which no one remembers today..." Main The spawning grounds were located between Volgograd and Saratov. Many sturgeon entered the Urals, along which they climbed to the mouth of the Sakmara. It also goes to spawn in other rivers of the Caspian Sea: Kuru, Terek, Sulak, Samur. In the Azov Sea basin, the most numerous were 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.
Complex structure There is also a spawning population of the Ural sturgeon, 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. Sturgeon living in rivers Eastern Siberia(Lena, Olenek, Yana, Indigirka, Kolyma), they are classified into a special subspecies - the Yakut sterlet 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 more slowly than the Russian sturgeon, and matures late: males are no earlier than 15–18 years old, females - at 18–20 years old. 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 penetrated into 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 major 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 Pacific coast 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 of these species, with the exception of the American lake sturgeon, are very rare and commercial value Dont Have.
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 fish are very small, often almost completely covered with skin, and vision does not play a big role 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. Two the latter type 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 the large shovelnose there are from 1 to 9 sharp spines, which probably play an important role in 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 sharp change in the water regime of the Amu Darya and Syr Darya as a result of irrigation hydroconstruction, 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.
More important than all sturgeon fish beluga(Huso huso), the giant of the entire family and clan; this fish reaches 8 m, and according to Lindeman, even 15 m in length and from 1000 to 1600 kg in weight*.
* The size that beluga can reach is greatly exaggerated: the length of record specimens does not exceed 5 m. The maximum life expectancy is 100 years.
The beluga is distinguished by a short triangular muzzle, flat antennae, a somewhat notched upper lip, divided in the middle by a lower lip, low back and front, and elevated dorsal scutes in the middle and small free-standing side scutes. The upper side is usually dark gray, the ventral side is dirty white; snout yellowish-white; the shields are the same color as the sides.
The distribution area is limited to the Black and Caspian seas, from where it penetrates into the rivers flowing into them.
Our current information about the life of fish in general leads us to the conclusion that the lifestyle of different species of sturgeon is, in general, almost the same.
They are actually marine fish and visit fresh waters only to breed or hibernate. We know nothing about how sturgeons live in the sea, to what depth they go and what kind of food they find in salt water. But, in any case, we must admit that in the sea, as in rivers, they prefer sandy or muddy soil and, almost burrowing in it, slowly move forward, crawling rather than swimming; with their sharp snout they tear up the silt and sand and look for themselves in seabed necessary food with lips extended forward*.
* Brem is wrong - sturgeons try to avoid areas with a muddy bottom and never burrow into the ground. In order to find food, they do not tear up the soil with their snouts or their antennae.
In the stomachs of those fish that visited the rivers, they found, along with animal food, almost decomposed remains of plants, but the latter could also accidentally get there. In any case, we must classify all sturgeons as predatory fish; about more known species we can probably say that they rise into the rivers following fish from the carp family and feed almost exclusively on them. However, during their travels, sturgeons rise to the upper layers of water and then move relatively quickly. These journeys are carried out in different species almost simultaneously (from March to May and late autumn) by entire societies, the size of which varies depending on the terrain and other circumstances. In rivers abounding in fish, the number of sturgeon has greatly decreased; This is all the more noticeable the more fishing gear improves; in some very big rivers on the contrary, they are still found in large numbers, since the vastness of these waters does not allow fishermen to pursue them everywhere**.
* * Sturgeon catches in the Caspian and Black Seas have decreased several times over the past few years; in other areas of the world, their numbers in natural reservoirs are also low. Therefore, sturgeon are being bred and grown artificially. These fish are characterized by fast growth and unpretentiousness; the scale of artificial cultivation of sturgeon, primarily Siberian sturgeon, Acipenser baerii, is rapidly increasing.
All sturgeons are among the most prolific fish known to us. Beluga sturgeons were found whose ovaries, with a total weight of 1400 kg, weighed 400 kg. Eggs are laid by fish on the bottom of the river, after which the fish quickly rise to the upper layers and swim into the open sea, while the young remain in the river water for quite a long time, maybe even the first two years of life.
The meat of all types of sturgeon is very tasty, as a result of which they are caught everywhere and eaten fresh, salted or smoked. Among ancient peoples, sturgeon was held in high esteem.
“Bring the sturgeon to the Palatine’s table, so that the feast will be decorated with such a rare dish,” says Marpial. Among the rich Romans, this fish was decorated with flowers when served to the table. In Greece, its meat was considered the most noble dish; in China it was reserved for the emperor’s table; in England and France, the right to eat sturgeon belonged only to the sovereign and the richest nobles; In Russia, sturgeon meat is also highly valued. However, sturgeon are caught for their caviar and swim bladder rather than their meat. As is known, caviar is prepared from their eggs, and the most beautiful glue is made from the bubble.
From representatives of the genus sturgeon(Acipenser) I will first mention the most famous Atlantic sturgeon(Acipenser sturios); it has a not very elongated muzzle, a narrow upper lip, a swollen and divided lower lip in the middle, simple mustaches closely adjacent to each other, large lateral scutes and low dorsal scutes on the sides, convex in the middle. The color of the upper part is more or less dark brown or yellow-brown, the lower part is shiny silvery-white; the scutes have a dirty white tint. The length can reach 6 m, but rarely exceeds 2 m*.
* The Atlantic sturgeon is the largest of the sturgeons, reaching over 3 m in length and over 300 kg in weight.
Atlantic Ocean and Mediterranean Sea. The North and Baltic Seas are home to Atlantic sturgeon, which, however, is also found off the eastern coast of North America; in the Black Sea it is completely absent and is also never found in the Danube basin**.
* * Lives in the Black Sea, but rarely.
Sterlet(Acipenser rithenus) is easily recognized by its elongated, narrow snout and rather long antennae, fringed on the inside; on a narrow upper lip a slight notch is visible; the lower lip is divided in the middle. The dorsal shields are slightly elevated in front, but rise gradually towards the tail and end in a point. The color of the back is dark gray, the belly is lighter; pectoral, dorsal and caudal fins are gray, ventral and anal fins are dirty white; the dorsal scutes are the same color as the back, the lateral and ventral scutes are whitish. Its length rarely exceeds 1 m; weight no more than 12 kg. The sterlet lives in the Black Sea and rises from there along all the rivers flowing into it, for example into the Danube and almost all of its tributaries. It is constantly caught near Vienna. In addition to the Black Sea, it is also found in the Caspian Sea, and therefore is also caught in all the rivers flowing into it, as well as in Siberian rivers, namely the Ob.
They tried several times to move the sterlet to the rivers of northern Germany, and, apparently, it acclimatized in the Oder***.
* * * Brehm is wrong. Sterlet is a freshwater fish and goes to sea extremely rarely.
Sterlet appears somewhat less frequently in the middle part of the Danube stellate sturgeon(Acipenser stellatus); it is very similar to the sterlet, lives in the same seas, is quite common in Russia and reaches about 2 m in length and 25 kg in weight; it can be easily recognized by its long, sharp, sword-shaped snout, simple antennae, notched upper lip, almost absent lower lip, and separated side scutes. The light reddish-brown back is sometimes bluish-black; the lower part of the muzzle is meat-colored; the sides and belly are white, the shields are dirty white.
- - Sturgeon - anadromous, semi-anadromous and freshwater fish; They inhabit the waters of the northern hemisphere - Europe, Northern Asia and North America...
Biological encyclopedia
- - 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...
Biological encyclopedic dictionary
- - taxonomic category in biol. taxonomy. S. unites closely related genera that have a common origin. The Latin name of S. is formed by adding the endings –idae and –aseae to the stem of the name of the type genus...
Dictionary of microbiology
- - family - One of the main categories in biological taxonomy, unites genera that have a common origin; also - a family, a small group of individuals related by blood and including parents and their offspring...
- - family, taxonomic category in the taxonomy of animals and plants...
Veterinary encyclopedic dictionary
- - The elongated spindle-shaped body of sturgeon fish is covered with reliable armor made of five rows of hard bone bugs: one row on the back, two on the sides of the body and two on the belly...
Pisces of Russia. Directory
- - A highly productive group of breeding queens descended from an outstanding ancestor and descendants similar to her in type and productivity...
Terms and definitions used in breeding, genetics and reproduction of farm animals
- - taxonomic category in biol. taxonomy. In S., closely related genera are united. For example, S. squirrels includes the genera: squirrels, marmots, ground squirrels, etc....
- - Thomas Nash had two sons - Anthony and John - to each of whom Shakespeare bequeathed 26 shillings 8 pence to purchase mourning rings. The brothers acted as witnesses in some of the playwright's transactions...
Shakespeare Encyclopedia
- - Alu-family - .A family of moderately repetitive DNA sequences known in many mammals and some other organisms...
Molecular biology and genetics. Dictionary
- - family of fish nadotr. cartilaginous ganoids. Dl. up to 9 m, weight up to 1.5 tons, 4 genera, 23 species, in the North. hemispheres. Anadromous, semi-anadromous and freshwater fish. Number is shrinking. 5 species are protected...
Natural science. encyclopedic Dictionary
- - a term very close, and for some authors coinciding with the term ore formation. According to Magakyan, “paragenetic ass. minerals and elements formed in certain geol. and physico-chemical. conditions”...
Geological encyclopedia
- - a family of fish from the ganoid order, suborder Chondrostei. Characterized by the following signs: the body is elongated, almost valval, with 5 longitudinal rows of bone scutes...
Encyclopedic Dictionary of Brockhaus and Euphron
- - a family of fish of the cartilaginous ganoid group. Snout more or less elongated; mouth without teeth, retractable, lower, 4 antennae in front of it. The internal skeleton is cartilaginous...
Great Soviet Encyclopedia
- - a family of fish of the superorder of cartilaginous ganoids. Length up to 9 m, weight up to 1.5 tons. 4 genera, 23 species, in the Northern Hemisphere. Anadromous, semi-anadromous and freshwater fish. The number is declining. 5 species - protected...
Large encyclopedic dictionary
- - sturgeon pl. A family of fish that includes sterlet, stellate sturgeon, beluga, sturgeon and...
Explanatory Dictionary by Efremova
"The Sturgeon Family" in books
Sturgeon breeds
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From the book Festive Table in Russian author collection of recipesSTURGEON FISH
From the book 1000 delicious dishes [for reader programs WITH SUPPORT OF tables] author DRASUTENE E.STURGEON AND STURGEON FISH*
From the book Great Culinary Dictionary by Dumas AlexanderSTURGEON FAMILY
From the book Recreational Fishing [with illustrations] author Kurkin Boris MikhailovichSTURGEON FAMILY Fish of this family differ significantly from all others in that on their elongated, spindle-shaped body there are five longitudinal rows of bony bugs - convex, irregularly shaped on top. One row of them is located on the back, two - on the sides of the body, and two -
Sturgeon family
From the book Catching Popular Fish Species author Kataeva Irina VladimirovnaSturgeon family
Sturgeon
From the book Profitable Fish Farming author Zvonarev Nikolai MikhailovichSturgeon The possibility of growing sturgeon near your home is of particular interest. Most widely used for commercial cultivation the following types and hybrid forms: Lena and Russian sturgeon, beluga, sterlet, bester (a hybrid of beluga and sterlet),
FAMILY OF PUMAS?
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From the book Incredible Cases author Nepomnyashchiy Nikolai NikolaevichFAMILY OF PUMAS? Not for the first time, finding themselves without help, local farmers are trying to solve an ominous mystery on their own. In 1986, flocks of sheep in Cinco Villas de Aragon were attacked by some cruel beast. The newspaper Diario de Navarra reported the incident as follows:
Sturgeon fish
From the book Encyclopedic Dictionary (N-O) author Brockhaus F.A.Sturgeon fishes Sturgeon fishes (Acipeuseridae) are 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 bony scutes; muzzle
Family
From the book Encyclopedic Dictionary (C) author Brockhaus F.A.Family Family (famila) – taxonomic group, proposed in 1780 by Batsch and usually encompassing several genera (genera.), although there are S. containing only one genus. Several (or even one) S. form a suborder or detachment (subordo and ordo). Sometimes S. contains
Family
From the book Big Soviet Encyclopedia(CE) of the author TSBSturgeon
From the book Great Soviet Encyclopedia (OS) by the author TSBbb) The whole family
From the book Outline of Christian Moral Teaching author Feofan the Reclusebb) The whole family Under the head and the whole family - all its members. First of all, they must have a head, not remain without it, and not allow there to be two or more of them. This is required by simple prudence and their own good, otherwise impossible, p) Then, when
Sturgeon is not only rare, but also a large fish, which in size significantly exceeds other species of sea, river and lake inhabitants. The article discusses external characteristics fish, their habitats, as well as benefits and harms. Recommendations for breeding and growing sturgeon are presented.
Description, structure and characteristics
Sturgeon – big fish. The body length of large species can reach about 6 meters. Weight Limit fish is 816 kilograms. This is exactly the body mass of the world's largest white sturgeon. But the average commercial fish weighs 12-16 kilograms.
The fish has a small head and an elongated snout, spatulate or cone-shaped. Retractable mouth, 4 antennae at the end of the snout. The lips are fleshy, the lower lip is torn, there are no teeth. The fry grow small teeth, but disappear over time. The gill openings of sturgeons are the same as those of sharks; regular gill rakers are located on their inner surface.
The sturgeon's skeleton consists of cartilaginous tissue, there are no vertebrae, the notochord is preserved throughout the life of the fish. The body is spindle-shaped and highly elongated. The fish has no scales, but its body is covered with five rows of special scutes-bugs - diamond-shaped bony scales. Each species of sturgeon is characterized by a certain number of bone bugs.
The sturgeon has a hard pectoral fin, its front ray, similar to a spine, is especially thick and pointed. As a rule, the age of the fish is determined by the transverse cut of the front ray. The dorsal fin has from 27 to 51 rays. The anal fin may contain from 18 to 33 sharp rays.
The sturgeon is most often gray in color. The color of the back can be light gray, light brown, grayish-black, yellowish or green. The fins are characterized by a dark gray tint, the sides are brownish, the belly is white, gray with blue or grayish with yellow.
Sturgeon is one of the long-lived fish. On average, fish live 40-60 years, while the lifespan of some fish can reach 100 years.
Population and species status
In the 21st century, the sturgeon is especially at risk of extinction, the reason for this is human activity: environmental degradation, overly active fishing, which continued until the 20th century, poaching.
The trend towards a reduction in the number of sturgeons became obvious back in the 19th century, but active measures began to be taken only in last decades: fight poachers, raise fry on fish farms and then release them into the wild. Today in Russia it is strictly prohibited to catch almost all types of sturgeon.
Types of sturgeon
In Russia, sturgeon live in places from the White Sea to the Caspian Sea. Fish are found in the basins of Siberian rivers, in the east - in the Pacific Ocean, in the west, sometimes in the Baltic Sea.
Amursky
It is found in the basins of the Amur River, including in floodplain lakes: Kizi, Boloni, Orel-Chle. The Amur sturgeon is distinguished by the presence of smooth gill rakers with 1 apex. An endangered species. The length of the Amur sturgeon reaches 3 meters and weighs about 190 kilograms, the average weight does not exceed 56-80 kilos.
Representatives of sturgeon are distinguished by their pointed, elongated snout. The fish feeds on larvae of mayflies, caddis flies, lampreys, various crustaceans, and small fish. During the spawning period, schools of fish go up the river to the Nikolaevsk-on-Amur region.
A fish belonging to the beluga genus. It is a large fish, the length of which reaches more than 4 meters and weighs up to 1000 kilograms. Kaluga is considered a long-liver, because with a weight of about 600 kilograms it can live up to 50 years. The diet includes fish: pink salmon, silver carp, carp, chum salmon. Small individuals feed on minnows and lampreys. Puberty occurs late - by 18-20 years.
Inhabits the Amur basin along its entire length. Found in Lake Orel, Ussuri. Does not go into the Sea of Okhotsk.
Atlantic (Baltic)
A large fish, the length of which can reach 6 meters. The maximum recorded weight of the fish is 400 kilograms. The Atlantic sturgeon has large bugs and has three pairs of large fused scutes on its tail. The color of the Atlantic sturgeon's back is grayish-olive, its sides are lighter than its back, and its belly is white.
The habitat is the Black Sea and the Bay of Biscay, where no more than 300 individuals are found. A small number of fish are found only in France in the Garonne River.
The Atlantic sturgeon prefers to feed on small fish (gerbil, capelin, anchovies), worms, crustaceans and mollusks.
A large fish, the length of which reaches 2.2 meters and weighs about 80 kilograms. It is characterized by an elongated, narrow, slightly flattened snout. The back of the sturgeon is black-brown, the belly is white, the sides are lighter than the back.
Stellate sturgeon prefers to feast on mysids, crustaceans, various worms and small fish. The stellate sturgeon lives in the basins of the Black, Azov, and Caspian seas. During the spawning period, the fish goes to Kodori, Volga, Inguri, Ural, Southern Bug, Kura, Dnieper, Kuban, Don.
The natural habitat of the sterlet is the rivers of the Baltic, Black, and Azov seas. Fish is found in the following rivers: Ural, Dnieper, Sura, upper and middle Kama, Yenisei, Irtysh, Ob, Volga, Don. Previously, sterlet was found in Lakes Onega and Lake Ladoga. The fish is considered a vulnerable species.
Sterlet is a medium-sized fish. Puberty occurs early: males are ready for spawning at the age of 4-5 years, females - at 7-8 years. Another difference between the sterlet and other sturgeons is the presence of fringed antennae and a large number of lateral bugs: there are more than 50 of them.
Sterlet is a freshwater fish, but there are few semi-anadromous forms. The maximum length of the sturgeon variety reaches 1.25 meters and weighs 16 kilograms. The average size sterlet - 40-60 centimeters. The snout of the fish is sharp or blunt, the color varies from brownish-gray to brown. The belly is white with yellowish tint.
Sterlet feeds on insect larvae, leeches, other bottom organisms, and small fish in small quantities. A valuable hybrid form of sterlet and beluga is bester.
The advantage of the sturgeon is that it thrives equally well in both fresh and salt water, due to which its habitat extends over many kilometers. Representatives of this species are found in the Black, Caspian, Azov, Aral Seas, and in river basins adjacent to these reservoirs. Many individuals live in the Sefidrud River, the Urals, and the Kura.
Adult spiny fish can reach more than 2 meters in length, but many representatives of this species are smaller. The spine is characterized by an elongated body with cone-shaped spines on the back. Unlike other representatives of sturgeon, the sturgeon has fringed antennae located near the lower lip.
The color of the thorn varies from light gray to greenish, the belly is light. There are star-shaped scales on the surface. Thorn is a fish listed in the Red Book of Russia.
Ozerny
The lake sturgeon is a large fish with a blunt snout. Maximum size, officially registered - 2.74 meters with a mass of 125 kilograms. The sturgeon's body color can be greenish-brown, black with a gray tint. The belly is white or slightly yellow.
The diet of the lake sturgeon includes all kinds of bottom microorganisms; the sturgeon feeds less often on fish. The fish's habitat is the Great Lakes system, Lake Winnipeg, and the basins of the Saskatchewan, Mississippi, and St. Lawrence rivers.
Russian (Caspian-Black Sea)
A valuable species of sturgeon, which has gained popularity due to the exceptional gastronomic qualities of its meat and caviar. An endangered species. The fish has a blunt, short snout and antennae growing towards the end of the snout. The maximum length of an adult reaches about 2.36 meters and weighs 115 kilograms. But usually the weight of Russian sturgeon is 12-24 kilograms with an average length of 1.45 meters. The color of the back is grayish-brownish, the sides are with a yellow tint, and the belly is white.
The Russian sturgeon lives in all major water areas of Russia. Found in the basins of the Caspian, Azov and Black Seas. During the spawning period, fish go to the Mzymta, Psou, Volga, Rioni, Terek, Danube, Don, Dnieper, Kuban, Samur and other rivers.
Depending on the habitat, the diet of representatives consists of worms, mysids and amphipods. Russian sturgeon prefers to eat fish: shemaya, mullet, herring, sprat. IN natural conditions sturgeon produces hybrid offspring with thorn, stellate sturgeon, sterlet and beluga.
Persian (South Caspian)
The Persian sturgeon is an anadromous species that is a close relative of the Russian sturgeon. Security status: on the verge of extinction. The maximum size of a sturgeon is 2.42 meters and weighs 70 kilograms. Representatives are characterized by a large, long, slightly curved snout and a gray-blue back, blue sides with a metallic tint.
The fish's diet consists of benthos and small fish. Sturgeon is found in the middle and southern regions of the Caspian Sea, the Caspian Sea and off the Black Sea coast. During spawning they go to the Rioni, Volga, Enguri, Ural, Kura.
A large fish, the weight of which can reach 1500 kilograms and a length of more than 4 meters. The fish's snout is similar in appearance to that of a pig. The mouth is large, sickle-shaped, the lips are thick. The eyes are small and blind. The body is covered with large scales. The back is grayish-brown in color, the belly is light, almost white.
Beluga lives in the Black, Azov and Caspian seas. Rarely found in the Adriatic Sea. It goes to spawning in the Dniester, Volga, Dnieper, Don, and Danube. Slightly less common in the Terek, Ural or Kura rivers.
Beluga fry feed on river plankton, caddis and mayfly larvae, eggs and fry of other fish. Having matured, the fish eat juvenile sturgeon and stellate sturgeon, crustaceans, mollusks, gobies or sprat, carp and herring.
Sakhalin
A rare species of sturgeon. The average length of adult individuals reaches 1.5-1.7 meters and weighs 35-45 kilograms. The largest individuals can reach up to 2 meters and weigh about 60 kilograms. Adult Sakhalin sturgeons have a large, blunt snout and a greenish-olive color.
Sturgeons feed on various bottom inhabitants: snails, insect larvae, small shrimp, mollusks, crustaceans, and small fish.
The habitat covers the cold waters of the Seas of Japan and Okhotsk, the Tatar Strait. The sturgeon goes to spawn in the Tumnin River, located in the Khabarovsk Territory.
Habitats, migrations and distribution
Sturgeons are freshwater, anadromous and semi-anadromous. Migratory fish are those that live in the sea and then in rivers. During spawning, they migrate from the sea to rivers or vice versa, which is much less common. Semi-anadromous fish are a group of fish that live in coastal areas seas or in seas-lake. During spawning they migrate to the lower reaches of rivers.
The natural habitat of the sturgeon passes through the reservoirs of the Northern temperate zone Europe, northern Asia and North America. For millions of years evolutionary development sturgeon has adapted well to living in temperate conditions climate zone, fish tolerate low water temperatures well and can go hungry for a long time.
Sturgeon is a bottom-dwelling fish, swimming at depths from 2 to 100 meters. Migratory species of sturgeon live in coastal waters seas and oceans, but they spawn in fresh river water, where the fish enter, swimming against the current, covering impressive distances. After breeding, schools of fish go back to the sea.
Semi-anadromous species of sturgeon live in the salty coastal waters of the seas and oceans, spawning at the mouths of rivers, without going upstream. Many freshwater species of sturgeon do not undergo long migrations; they prefer to lead a sedentary lifestyle in the waters of rivers and lakes, where they feed and reproduce.
All sturgeons spawn in the spring and summer, but migrate to the spawning grounds at different times. Because of this, sturgeon are divided into seasonal races - winter and spring. Spring birds go to breeding grounds before spawning, in the spring. Winter crops - in autumn period when the eggs have not yet matured.
Spawning
Puberty in sturgeon occurs between the ages of 5 and 21 years. Females spawn approximately once every 3 years, several times during their lives, males - more often. Spawning of various sturgeon fish can take place from March to November. Peak spawning occurs in mid-summer.
A prerequisite for a successful reproduction process and further maturation of the offspring is freshness of water and a strong current. Sturgeons will not be able to reproduce in stagnant or salty water. The temperature of the water is also important; the warmer it is, the worse the caviar will ripen. Embryos will not be able to survive when heated to 22 degrees.
During one spawning, female sturgeon are capable of throwing up to several million eggs, the diameter of which ranges from 2 to 3 millimeters, and their weight is up to 10 mg. Females lay eggs into crevices of the river bottom, into cracks in large boulders, and between stones. Sticky eggs adhere firmly to the substrate, due to which they are not carried away by river currents. Embryos develop from 2 to 10 days.
What does sturgeon eat?
The sturgeon prefers to feast on various bottom organisms and fish. The composition of the diet directly depends on the age of the fish and its habitat:
- Sturgeon fry prefer zooplankton (daphnia, bosminamia, cyclops), but can feed on very small crustaceans and worms.
- Juveniles They feast on insect larvae, small shrimp, snails and crustaceans. In the stomachs of fry there are often inedible particles, most likely absorbed from the muddy bottom.
- Adult eats 85% protein foods. Sturgeons become especially voracious before breeding: they eat almost everything they can find on the bottom, including various crustaceans (usually amphipods) and representatives of the order Cladocera. They love to feed on the larvae of insects, caddis flies, and mosquitoes. They feast on clams, mussels, leeches, shrimp, and worms.
When the amount of protein food is limited, sturgeons eat algae. The fish diet consists of sand lance, herring, sprat, gobies, anchovies, sprat, pike perch, silver bream, mullet and other types of small and medium-sized fish.
During the spawning period and after the breeding process, the sturgeon stops feeding and switches to eating vegetation. Within a month, the fish recovers, its appetite returns, after which it again goes in search of food for further survival.
Sturgeon caviar is one of the most elite and expensive delicacies in the whole world. The cost of 1 kilogram of product often reaches up to 6 thousand dollars. The high price of fish is due to the annual decline in their population. Taking into account that industrial fish production is prohibited in many countries, the main suppliers of the product are artificial fish.
Real black caviar has a refined, lightly salted taste with a slight aroma of seaweed. The color of caviar varies from light gray to dark brown. Due to the high cost of the product and its unique color, caviar was called “black gold.”
The delicacy is used as a cold appetizer with sparkling wine, vodka and dry champagne. The delicacy is served pure in crystal vases or in turtle shells with small silver spoons. Many people prefer to make sandwiches with butter and caviar. The product is also combined with onions, hard cheese, vegetables, eggs and herbs.
So that caviar does not lose its unique taste and attractive appearance, it is served 15 minutes before consumption. Until this point, the snack is stored in the refrigerator. In addition to its excellent gastronomic properties, sturgeon caviar is especially valued in natural medicine. It contains at least 30% easily digestible proteins, 12% fatty acids, 6% vitamins and mineral salts.
It is useful to use caviar for the following problems:
- atherosclerosis;
- iron deficiency anemia;
- nervous system disorders;
- chronic fatigue;
- osteoporosis.
It is useful for pregnant women and breastfeeding mothers to eat sturgeon caviar, due to the vitamin E and choline it contains. It is recommended to consume the product during the post-rehabilitation period (after operations) - it has a general strengthening effect.
To get maximum benefit from the product, only high-quality caviar is consumed.
Breeding and rearing
In nature, many species of sturgeon fish easily form crosses, due to which a hybrid of sterlet and beluga - bester - was artificially bred for commercial cultivation. Today, many people are increasingly resorting to breeding sturgeon at home. If all stages of the technological process are followed, it is possible to obtain products that will be no worse in quality than livestock caught in natural reservoirs.
Features of cultivation:
- To grow sturgeon, you will need to select a plot of land whose area will be at least 30 square meters. It is recommended to choose a location away from roads, because sturgeons are shy fish. It is very important to take care of heating in winter.
- Professional sturgeon farming on a large scale requires about 5-7 tanks where adult fish will be sorted. But beginning breeders can use one small container, 2-3 meters in diameter and at least 1 meter deep. Such a pool will allow you to grow about 1 ton of fish.
- For good fish growth, filters, pumps, compressors, and pipelines are installed in the pools. It is advisable to purchase an automatic feeder and incandescent lamps. When using plumbing to supply water, the fish farmer must ensure that no residual chlorine enters the pool. The volatile compound can be eliminated by installing a carbon filter.
- Take care of the fish regularly. Be sure to keep the pool clean: change 10% of the water daily, remove silt from the walls, control temperature regime and serviceability of equipment. The optimal water temperature in cold weather should be at least 17-18 degrees, in summer – 20-24 degrees.
- When purchasing fry, it is difficult to calculate the rate of their future growth; the fish are sorted into different tanks weekly. At the same time, the cultivation of strong specimens takes no more than six months, medium – 7 months, strong – up to 9 months.
Successful sturgeon breeding directly depends on the nutrition of the individuals. They are fed nutritious high-calorie food, which should contain the following components:
- protein – at least 45%;
- crude fats – 25%;
- dietary fiber – 2%;
- phosphorus and lysine – 1%.
When choosing food for sturgeon, it is recommended to give preference to water-resistant food that swells and sinks in water. Fry are fed 5-6 times a day, adults - 4 times a day. At the same time, equal time intervals must be maintained between feedings, otherwise the fish may refuse to eat.
The benefits and harms of sturgeon
Sturgeon is rich in easily digestible proteins, due to which the product is quickly digested and is often recommended by nutritionists for various diets. The composition of sturgeon meat is rich in rare beneficial acids, including glutamic acid, as well as vitamins A, C, PP and group B. Sturgeon meat is a delicious product that contains useful macro- and microelements: potassium, fluorine, phosphorus, iodine, calcium, nickel , magnesium, molybdenum, sodium, chromium, iron, chlorine. The calorie content of sturgeon is 160 calories per 100 grams of product.
The calorie content of 100 grams of sturgeon caviar is about 200 calories. The product is rich in healthy proteins and lipids. It is useful to eat caviar for people who are in poor health after a serious illness and for those who have undergone aggressive treatment.
With regular consumption of sturgeon, which contains healthy fatty acids, blood vessels and heart muscles are strengthened, which helps lower cholesterol levels in the blood and reduce the risk of myocardial infarction. Caviar has a beneficial effect on the growth and strengthening of bone tissue and improves skin regeneration.
Consumption of sturgeon caviar and fish meat has a beneficial effect on human health and well-being:
- Sturgeon fat helps improve brain function and strengthen the cardiac and vascular systems.
- When consumed, fish fights stress and depression.
The most valuable caviar is stellate sturgeon, beluga and Russian sturgeon. The product differs in color and size.
The danger for humans is that sturgeon caviar and meat itself can be contaminated with botulism pathogens. Because of this, fish are purchased only from reliable suppliers. When purchasing, a thorough visual inspection of the product is carried out.
People suffering from diabetes and obesity should consume fish carefully to avoid the risk of deterioration in health.
Sturgeon fishing
Sturgeon fishing begins immediately after spawning. Sturgeon are often found in the mouths of tributaries, large shallows and spits, sandy coastal areas with stumps and boulders, gaps between dams, extensive oxbow lakes, places with slow flow, artificial coastal fills.
Taking into account the rarity of sturgeon, and taking care of the safety of the species, it would be more correct to use the services of paid reservoirs. You won't be able to catch trophy fish with them, but catching small specimens is quite possible. Fish weighing 1-4 kilograms are released into paid reservoirs. Active biting is observed in fish released the day before.
It is necessary to prepare gear for catching sturgeon based on its bottom-dwelling lifestyle. Often they use all kinds of donks, jig spinning rods with hard blanks, and feeder tackle. Bolognese fishing rods are not suitable because fish can simply break them. Choose a rod with the required length, depending on whether the fish will be caught from the shore or from a boat, with long casts or in the near zone.
Most fishermen prefer to use barbless hooks to reduce trauma to the sturgeon's soft mouth. Be sure to prepare a wide carp landing net and gloves that will protect your hands from sturgeon thorns. For fishing, it is recommended to use fish fillets, smoked capelin, large shrimp, and bunches of earthworms.
It is believed that catching sturgeon will be successful using pearl barley or toothless meat, because in the natural environment sturgeon happily suck these mollusks from the shell.
The bait for sturgeon is prepared on the basis of pellet for carp - it will be large enough so that small fish will not take it away, it will slowly dissolve and spread a pleasant aroma. Sturgeons do not have good eyesight, but they have an excellent sense of smell; for this reason, you should not use unnecessary flavorings. And it is also undesirable to feed this fish heavily.
To catch a sturgeon, you will need to immediately respond by hooking, even if the bite is barely noticeable. Sturgeon fish are able to squeeze the bait gently without swallowing the hook. The caught sturgeon sharply presses to the bottom and zealously resists. They wear him out quickly and confidently. The sturgeon can break loose when thrown out of the water, therefore, you cannot hesitate.
Sturgeon is one of the oldest and most popular fish on earth. Archaeological finds dating back to 3 thousand years BC indicate that already in those days sturgeon caviar was successfully used by sailors in canned form. In the army of Alexander the Great, sturgeon caviar served as food for soldiers.
In the 20th century, one French woman managed to notice that women who process sturgeon caviar, despite their hard work, have very beautiful and smooth skin on their hands. After this, they began to study the miraculous properties of black caviar and launched a line of cosmetics, which enjoyed incredible success. Today they have stopped producing such cosmetics due to the fact that it is not profitable.
In the middle of the 20th century, an Atlantic sturgeon weighing 213 kilograms was caught in the Neva, and 80 kilograms of caviar were obtained from it.
Sturgeon – unique fish, which gained popularity for its large size, elongated body and amazing exterior. All sturgeon fish are in great demand, because their value healthy meat very big. You can earn a huge fortune not only by selling meat, but also sturgeon caviar.
The sturgeon is a large fish belonging to the ray-finned class, and their subclass is considered to be a cartilaginous ganoid.
In length, such a slave can be about 6 meters, while the weight reaches 16 kilograms.
Structure
The fish itself basically only has cartilage tissue, since it does not have vertebrae. But the chord remains throughout her entire life. The body looks elongated and has a spindle shape.
The body lacks the usual scales. Basically, the body contains bone scales, which are arranged in five rows. Each type of fish has its own individual location. There are also tubercles and bone plates.
The ray, which is located in front, is long and pointed, very prickly. The fin on the chest is very strong and hard. The fin located on the back smoothly passes into the tail and has about 51 rays. The rays of the tail reach its end and envelop it on both sides. Up to 33 rays are contained on the anal fin.
It is important that all the rays are very sharp. The swim bladder of these fish is very developed.
The shape of the sturgeon's head is elongated, can be sharp or blunt, depending on the species. But they all have four simple antennae. Their oral cavity is lower due to the way they eat.
They have no teeth completely, although small teeth are formed in the fry. But as they grow older, they completely fall out. Their lips are fleshy, their lower part is interrupted. Inside the body are gill rakers. As a rule, there are up to 45 of them.
The color scheme of this fish is gray. The fins have a dark gray tint. The back can have different tones, but is often similar to the color of green or with a slight yellowness.
The belly is light, can be grayish with yellow or pure white. And the sides are brown.
Lifespan
This fish boasts the longest lifespan. Some species lived up to a hundred years.
On average, they live to be 50 years old. Therefore, they are classified as long-lived fish species.
Habitat
Sturgeons can live in fresh water as well as sea water. However, they do not go to the open sea. They live in the waters of the Northern Belt of the European part, North America and northern Asia.
Sturgeon tolerates it well low temperatures, and can go hungry for a long time. Therefore, it can exist in a temperate climate zone.
Such fish can swim at a depth of up to 100 meters, so they can live both in the sea and in the ocean. However, spawning occurs only in the waters of fresh rivers. Most sturgeon fish are not prone to migration; they live and breed in fresh rivers and lakes.
Nutrition
The sturgeon feeds on various types of plants that grow at the bottom of the reservoir. Their diet also consists of insect larvae and small fish. Basically, the diet of an adult consists of protein foods.
Before spawning, their appetite increases. And during the spawning itself and after, the fish switches to feeding on plants or may not eat at all. But after a month, they recover and return to their usual diet.
Types of sturgeon
Sturgeon has only 17 species, many of them are in the Red Book. Since their numbers have decreased many times. Below is a list of the most popular types.
Siberian. A very large species, up to two meters long. Individuals of this species are divided into two types: sharp-snouted and blunt-snouted. They live in fresh water and also pass sea water. Such individuals are found in Lake Baikal, in the Ob and Kolyma rivers, as well as in Lake Zaysan, which is located in Kazakhstan.
White. The largest species of sturgeon, smaller in size only than the beluga. The fish is migratory and primarily lives in Pacific reservoirs, which are located in the northern part of America.
Russian. This species was artificially created. But they have value, since there are fewer and fewer of them every year. However, they are completely unsuitable for food. They have an anadromous and residential form of habitat. Can be found in the waters of the Caspian, Azov and Black Seas. Spawning is already happening in fresh rivers.
Atlantic. The length of this individual is amazing, as it reaches a maximum of 6 meters. And the maximum weight is 400 kilograms. This species is on the verge of extinction. There are no more than 300 individuals left in the world, which live in the waters of the Black Sea and the Bay of Biscay.
Spawning
Puberty in females and males is completely different. So the male only matures between the ages of 5 and 18 years, and the females mature a little later, from 8 to 21 years.
The period depends on the habitat of the individual. Fish cannot reproduce every year. Females breed once every 5 years, and males a little more often.
Sturgeon breed in bodies of water where there is a strong current. The water must be fresh, and the temperature must be on average plus 15 degrees. Spawning takes place at a depth of 4 to 20 meters. It is important that at temperatures above plus 20 degrees the eggs die.
Sturgeon grows for quite a long time. It reaches average size at about the age of 12 years.
The sturgeon is not only one of the most popular fish, but also the oldest species. Scientists have long proven that eating this type of fish meat is extremely beneficial. And the eggs contain many useful substances that have a beneficial effect on the human internal body.
Today in the Russian Federation, catching any type of sturgeon is prohibited.
Photo of Sturgeon fish
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