Fish and other aquatic creatures

Sturgeon fish

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Cold water fish are chosen as neighbors for starlets:

Some aquarists manage to contain a sterlet with tropical species of fish, choosing a temperature that is comfortable for all inhabitants.

Small fish that the sterlet can swallow will not fit as neighbors. Tropical fish will be sick at low temperatures, so they will also not fit as neighbors.

The ancient predator and now a rare inhabitant of the rivers of the European part of Russia, listed in the Red Book. Sterlet with the right content can stand out even against the backdrop of bright overseas exotic.

Appearance

Sterlet is considered the smallest among all species of sturgeon. The body size of an adult individual rarely exceeds 120-130 cm, usually these cartilaginous are even smaller: 30-40 cm, and they weigh no more than two kilograms.

The sterlet has an elongated body and a relatively large oblong head of a triangular shape compared to it. Its snout is elongated, conical, with the lower lip split in two, which is one of the most noticeable distinguishing features of this fish. Bottom on the snout there is a number of fringed antennae, also characteristic of other members of the sturgeon family.

It is interesting! Sterlet can be of two forms: sharp-faced, which is considered to be classical and blunt-toed, in which the edge of the muzzle is somewhat rounded.

Its head is covered on top with accrete bone shields. On the body there is a ganoid scale with numerous bugs, interspersed with small comb-like projections in the form of grains. Unlike many species of fish, in the sterlet the dorsal fin is shifted closer to the tail part of the body. The tail has a typical shape for sturgeon, while its upper lobe is longer in length than the lower one.

The body color of a sterlet is usually quite dark, usually grayish-brown, often with a mixture of a pale yellow shade. The belly is lighter than the main color, in some specimens it may be almost white. It differs from another sturgeon sterlet, first of all, by an interrupted lower lip and a large number of scutes, the total number of which may exceed 50 pieces.

Character and way of life

Sterlet is a predatory fish that lives exclusively in rivers, and prefers to settle in fairly clean reservoirs with running water. Only occasionally can swim in the sea, but there it can only be found near the mouths of rivers.

In the summer, it is kept in shallow water, and young sterlet can also be found in narrow channels or bays near the mouths. By autumn, the fish goes to the bottom and lies in the grooves, called pits, where they overwinter. In the cold season, she leads a sedentary lifestyle: she does not hunt and does not eat anything. After the ice has opened, the sterlet leaves the pits at the bottom of the reservoir and goes upriver in order to continue its genus.

It is interesting! In contrast to most sturgeons, which are considered to be soloists, the sterlet prefers to keep in large flocks. Even in the pit for the winter, this fish goes not alone, but in the company of its many relatives.

In the same bottom recess, several hundred sterlets sometimes winter at the same time. At the same time, they can be so closely pressed to each other that they move with their gills and fins with difficulty.

How long does a sterlet live

Sterlet lives, like all other sturgeon fish, long enough. Its life in natural conditions can reach thirty years. Nevertheless, in comparison with the same lake sturgeon, which is 80 years old and even more, it would be wrong to call it a long-liver among the members of your family.

Sexual dimorphism

Sexual dimorphism in this fish is completely absent. Males and females of this species do not differ from each other either in body color or in size. The body of the females, as well as the body of the males, is covered with dense, resembling bony protrusions, ganoid scales, moreover, the number of scales is not too different in individuals of different sexes.

Habitat

Sterlet lives in rivers flowing into the Black, Azov and Caspian Sea. It is also found in the northern rivers, for example, in Ob, Yenisei, Northern Dvina, as well as in the basins of the Ladoga and Onega lakes. In addition, this fish was artificially settled in rivers such as the Neman, Pechora, Amur and Oka, and in some large reservoirs.

Sterlet can live only in reservoirs with clean running water, while it prefers to settle in rivers with sandy or stony pebble soil. In this case, the females try to keep closer to the bottom of the reservoir, while the males swim in the water column and, in general, lead a more active lifestyle.

Ration of sterlet

Sterlet is a predator, feeding mostly on small aquatic invertebrates. The basis of the ration of this fish is made up of bottom organisms, such as insect larvae, as well as crustaceans, various mollusks, and small-chain insects living at the bottom of the reservoir. The sterlet will not refuse from caviar of other fishes, she eats it especially willingly. Large individuals of this species may also feed on medium-sized fish, but at the same time try to miss too large prey.

It is interesting! Due to the fact that the sterlet females lead to the near-bottom lifestyle, and the males swim in open water, the fish of different sexes feed differently. Females seek food in the bottom sediment, and males hunt invertebrates in the water column. Hunt the starlets prefer in the dark.

Fry and young fish feed on animal plankton and microorganisms, gradually expanding their diet by adding to it first small and then larger invertebrates.

Reproduction and offspring

For the first time, the sterlet spawns quite early for sturgeon: males are 4–5 years old, and females - on reaching 7–8 years old. At the same time, it multiplies again 1-2 years after the previous spawning.

This period of time is necessary for the female to fully recover from the previous “genera”, which greatly deplete the body of the representatives of this family.

The breeding period for this fish begins at the end of spring or at the beginning of summer - approximately from mid-May to its end, when the water temperature in the reservoir reaches from 7 to 20 degrees, despite the fact that the optimum spawning temperature for this species is 10 -15 degrees. But sometimes spawning can begin earlier or later this time: in early May or in the middle of June. This is due to the fact that the water temperature required for spawning is not set for one reason or another. The level of water in the river where it dwells also affects exactly when spawning should begin in the sterlet.

Sterlet that lives in the Volga, is not sent to spawn all at once. Individuals living in the upstream, spawn slightly earlier than those who prefer to settle in the lower reaches. This is due to the fact that the spawning time of these fish falls on the largest spill, and it begins in the upper reaches of the river earlier than in the lower reaches. Sterlet caviar spawns on bystrin, in those places where the water is especially clean, and the bottom is covered with pebbles. She is quite prolific fish: the number of eggs laid by the female at a time can reach 16,000 or even more.

The sticky eggs deposited on the bottom develop several days, after which fry are hatched from them. On the tenth day of life, when the yolk sac disappears, the size of small sterlet does not exceed 1.5 cm. The appearance of the young in this species is somewhat different from the appearance of already adult individuals. The mouth of the larvae is small, cross-section, and the fringed antennae are approximately the same in size. Their lower lip is already split in two, as in adult sterlets. The upper part of the head in young fish of this species is covered with small spines. The young are colored darker than its adult relatives, the darkening in the tail part of the body of the young is especially noticeable.

For a long time, the young sterlets remain in the place where they were once removed from the eggs. And only by the autumn, reaching a size of 11-25 cm, they go to the river delta. At the same time, sterlets of different sexes grow at the same speed: both males and females do not differ from each other in size from the very beginning, just as, incidentally, they are the same in color.

It is interesting! Sterlet can interbreed with other fish of the sturgeon family, such as various species of sturgeon, for example, Siberian and Russian sturgeon or sturgeon sturgeon. And from the beluga and sterlet in the 1950s of the twentieth century, a new hybrid was artificially bred - the bester, which is now a valuable commercial species.

The value of this hybrid species is due to the fact that, like Beluga, it grows well and quickly and gains weight. But at the same time, unlike late maturing belugas, the bester, like the sterlet, is distinguished by early puberty, which makes it possible to speed up the reproduction of these fish in captivity.

Natural enemies

Due to the fact that the sterlet lives in the water column or even near the bottom of water bodies, these fish have few natural enemies.

And besides, the main danger threatens not adults, but roe and fry of sturgeon, which are eaten by fish of other species, including those belonging to the sturgeon family that live in places of sterlet spawning. At the same time catfish and beluga represent the greatest danger for juveniles.

Population and species status

Before, seventy years ago, the sterlet was one of quite numerous and prosperous species, but by now the pollution of water bodies with sewage, as well as unlimited poaching, has done its job. So for some time this fish is listed as endangered in the Red Book, and according to the international classification of protected species it would be assigned the status of "Vulnerable species."

Commercial value

Back in the middle of the 20th century, the sterlet was considered the most common commercial fish, whose catch was active, although it could not be compared with the pre-revolutionary catch rates, when almost 40 tons were harvested per year. However, at present, catching sterlet in its natural habitat is prohibited and practically not conducted. Nevertheless, this fish continues to be on sale, both fresh or frozen, and salted, smoked and in the form of canned food. Where does so much sterlet come from, if its catching in rivers has long been banned and considered illegal?

It will also be interesting:

The fact is that caring people engaged in environmental activities, who do not want the sterlet to disappear from the face of the Earth as a species, for some time now began to actively breed this fish in captivity, on specially built for these purposes fish farms. And, if at first these measures were taken solely for the sake of saving sterlet as a species, now, when this fish, born in captivity, has become quite a lot, the gradual revival of the old culinary traditions associated with this fish began. Of course, at present, sterlet meat cannot be cheap, and even in quality, captive-grown fish are inferior to those grown in natural conditions. Nevertheless, fish farms are a good chance for the sterlet not only to survive as a species, but also to become a common fishing species again, as it was several decades ago.

It is interesting! Sterlet, considered the smallest of sturgeon species, differs from other members of this family not only by its small size, but also by the fact that it reaches puberty faster than other sturgeon.

It is this, and also the fact that the sterlet is a fish, unpretentious to food, and makes it so convenient for breeding in captivity and for working on breeding new species of sturgeon, such as, for example, bester. Therefore, despite the fact that it is currently considered endangered, the sterlet still has quite good chances of survival as a species. After all, people are not interested in the fact that this fish has disappeared from the face of the Earth, and therefore all possible environmental protection measures are being taken to save the sterlet.

Tanks and equipment and for growing sterlet

At the very beginning of the breeding of this sturgeon breed, you can not construct an artificial reservoir, but simply purchase a standard plastic pool one meter deep and two and a half meters in diameter. For a year it can grow to a ton of sterlet.

In order for the fry to grow and develop, the pool must be equipped with filtration and aeration elements, and from time to time the tank must be cleaned. For this reason, those who decide to breed sterlet will need to purchase another compressor unit, pumps and filters.

If finances allow, it is advisable to buy an automatic feeder. When choosing a compressor and pump, you need to take such units that will handle a slightly larger volume of water than you have. This is done so that the equipment does not work at the limit of possibilities and lasts as long as possible. Over time, you can buy another pool and significantly expand the farm.

Forage and sterlet fry

It is very difficult to bring out sterlet fry at home, and without proper equipment and skills it is completely impossible. For this reason, it is best to purchase them at one of the proven fish farms engaged in the cultivation of this breed of sturgeon.

It’s not worth saving, because the better and healthier the fry are, the sooner they will grow, which means the breeder will be able to make a good profit. Regarding feed additives for starlet, there are some peculiarities that need to be considered when breeding. The feed should be the same size as the fish. That is, for small fish - smaller, and for large individuals - more.

Feed additives for this sturgeon species should have a lot of calories and be rich in protein, lysine, fat, and fiber and phosphorus. Most of the food should contain exactly protein and fat.

For this reason, the stern is also not worth saving. It is better to buy it for starlet, as in this case it will fully meet its needs. Another feature of feeding is strict adherence to temperature. It should reach twenty-twenty-four degrees. Such a temperature regime must always be maintained in the reservoir, otherwise the fish will be poorly eaten and, accordingly, grow.

Peculiarities of home breeding sterlet

The most exciting question for farmers is when will the fish start growing and making a profit. So how does the fry grow up?

Often for breeding sterlet take five grams of fry. They all grow in different ways. Within six months, half of the fish may weigh five hundred grams, the second half will weigh less, and after a while it will “overtake” by the weight of the more “well-fed” brethren.

The most popular product is fish that weighs five hundred grams or more. She willingly take the owners of supermarkets and restaurants. In our country, the consumption of sterlet is not too high, but all the same, since there is practically no such fish on the market, it diverges with a bang. For this reason, this kind of business is considered very profitable.

After the largest individuals have grown, the smaller ones need a few more months to grow up. After a month and a half, medium-sized fish grows, and then grows smaller. Within nine months after landing in the pool of the first batch, you can upload a new one. If breeding goes well, you can purchase several more pools and expand the farm.

Growing sterlet as a business

You will surprise anyone with such a business as growing aquarium fish, but few people realize that a real mini farm for growing sterlet can be created at home. If you make this effort, you can earn very good money. Where to start building your successful business?

About business benefits

Sterlet belongs to the sturgeon family. It is quite simple and unpretentious in content, if you approach this with the mind. You can organize your mini farm even in apartment conditions. This is precisely the first advantage in growing sterlet. But there are the following advantages of this type of business:

  • healthy meat and caviar: these products are in great demand on the market and the demand for them is growing every day,
  • Sterlet is unpretentious in its content and therefore even a novice can comprehend the peculiarities of its rearing, for growing this type of sturgeon in the home will not be expensive.

Of all the advantages listed above, one can say that the business of breeding sterlet is quite a profitable occupation.

Choosing a place for breeding fish

You can breed a sterlet in any conditions. The choice of location will not affect the final result, but only if you follow all the necessary instructions.

If the breeder decided to breed fish in a private house, he should provide for her a spacious room of thirty squares, which will be well heated, especially in winter.

In winter, in order for the sterlet to grow and develop normally, it must provide a temperature regime of no less than seventeen degrees, and in summer the temperature should not fall below twenty degrees. Также для ее выращивания можно применять поликарбонатную теплицу, в которой можно поместить пластиковый бассейн.

Место для проживания мальков

Если у заводчика имеется необходимый капитал, то лучше всего купить специальное оборудование у производителя. После установки, его можно будет уже сразу использовать, причем в него будут включены все необходимые детали.

Если же денег на закупку оборудования не слишком много, его можно создать самостоятельно. Для этого можно использовать метровый пластиковый бассейн с диаметром от двух до трех метров: в нем можно вырастить около тонны стерляди в год.

Оснащение для бассейна

Для того, чтобы создать рыбе нормальные условия для жизни бассейн, необходимо оснастить аэраторами, компрессорами и фильтрами. You will also need pumping equipment, as the pool must be cleaned. To grow sturgeon was easier, the pool must be equipped with an automatic feeder. Special care must be taken when choosing a pump and compressor. You need to buy powerful units, as they will last much longer than their low-power counterparts.

Breeding sterlet begins with the purchase of fry. It is best to do this in specialized fish farms with a proven reputation. You should not take the first fry, you must consult with experts before purchasing them in order to purchase really high-quality fish that will not die out in a few days.

Choosing the right feed

To breed a sterlet is quite simple, the main thing is to choose the right food. Since the sterlet prefers to eat at the bottom, it is necessary to buy only that food that sinks and smells good, as the fish mostly look for it by smell.

Also, the feed should not break and crumble in water. For starlet, this is important because she does not swallow it right away, but eats gradually. In addition, the feed should be soft, high-calorie tasty and contain protein, phosphorus, fiber, lysine and fats. On such additives, fish not only grow well, but do not get sick.

Growing sterlet in a pond

Breeding starlets in an apartment or house, is quite simple, but still has its drawbacks. For example, they include a small area, maintaining the necessary microclimate and so on. It is much easier to breed fish in a pond.

It can be grown both in ready, and in the created reservoir. If the pond is old, then before launching the fry, it must be cleaned.

If you create a pond yourself, you must first lime it. To do this, you must fill the bottom with a small lime layer, fill it with water and rinse thoroughly. This procedure is carried out a couple of weeks before running the fish.

The bottom is best shaped as a bowl. Do not forget about the algae and various living creatures that fish will consume. You can wind up in the pond and shellfish. To start the fry best suited the beginning of summer.

An example of a successful business

As an example of home breeding sterlet, you can cite the mini farm of Alexander Yemtsev from Art. Dolzhanskaya Yeisk district. He organized a minifarm in a pond in the courtyard of a proper house. He not only breeds fish for sale, but also during his free time he fishes with his friends in his home pond. Alexander's plans include creating two more such reservoirs and growing other sturgeon breeds.

Growing sturgeon at home is quite profitable and under all conditions, it is quite simple. Therefore, if you want to do the breeding of fish, feel free to start the implementation of the dream.

Sturgeon - description, structure, characteristics, photos. What does sturgeon look like?

Sturgeon is a big fish, the length of the body of large species can reach 6 meters. The maximum weight of sturgeon is 816 kg (it was exactly the weight of the world's largest white sturgeon). However, on average, commercial fish weigh 12-16 kg.

The sturgeon skeleton consists of cartilage tissue, the vertebrae are absent, and the chord persists throughout the life of the fish. The body of a sturgeon of a spindle-shaped form, is strongly extended, deprived of scales and covered with five rows of special scutes-scutes - diamond-shaped bone scales. Along the ridge there is one row, on average containing from 10 to 19 flaps, a pair of side rows is composed of 25-56 elements, and two rows located on the belly usually consist of 7-15 flaps (depending on the species).

Photo by: Cacophony

For each species of sturgeon is characterized by an individual number of bone scutes. Each of these elements does not grow together with the adjacent one and is covered with annular stripes. Also, small stellate bone plates and hillocks are randomly scattered throughout the body of the sturgeon.

The pectoral fin of the sturgeon is very hard, and its front ray, like a thorn, is especially thick and pointed. The age of the sturgeon is often determined by the transverse cutting of the front beam. The dorsal fin contains from 27 to 51 rays and is markedly related to the tail. The rays of the caudal fin extend beyond the end of the tail and round it on both sides. The anal fin can contain from 18 to 33 sharp rays. Swimming bladder well developed.

Photo by: Haplochromis

The head of a sturgeon is small, the snout is elongated, conical or spatulate, sharp or slightly dull. At its end there are 4 antennae, as a rule, simple, devoid of fringe (except sterlet, in which the antennae are fringed). The mouth of the sturgeon is retractable and has a lower location, which is associated with the peculiarity of fish feeding on bottom organisms. The lips are rather fleshy, the lower lip of the fishes is interrupted, the teeth are missing. In fry small teeth grow, but then disappear. The gill openings of sturgeon are the same as those of sharks, and in the process of evolution are transformed into sprinklers. On their inner surface, there are simple gill rakers, the number of which varies from 24 to 45 pieces.

Photo by: Haplochromis

The color of the sturgeon is predominantly gray. The back can be light gray, grayish black or light brown, cast greens or yellow, the fins are usually dark gray. In fish, the sides are brownish, the abdomen of the sturgeon is white, gray with blueness or greyish yellow.

Where does sturgeon live?

Sturgeon can be freshwater, aisle and semi-aisle.

Reference: Passing fishes are fishes that spend part of life in the sea, and the other part in rivers. During spawning, they migrate from the sea to the rivers or vice versa, which happens less frequently.

Semi-passage fish is a group of fish that lives in the coastal zones of the seas (they do not go far into the sea) or in the seas-lakes (Aral, Caspian). During spawning migrate downstream.

The natural habitat of sturgeon passes through the waters of the northern temperate zone of Europe, the northern part of Asia and North America.

For millions of years of evolutionary development, the sturgeon is well adapted to live in a temperate climate zone, the fish tolerate low water temperatures well and can go hungry for a long time.

Sturgeon is a bottom fish that swims at a depth of 2 to 100 meters. Sturgeon migratory species live in the coastal waters of the seas and oceans, but their spawning occurs only in fresh river water, where fish enter while swimming against the current, and at the same time they travel impressive distances. At the end of spawning shoals of fish go back into the sea. Semi-passage species of sturgeon live in the salty coastal waters of the seas and oceans and make spawning migrations to the mouths of the rivers, not going upstream. Most freshwater species of sturgeon are not subject to long-term migrations, but lead a sedentary life in the waters of rivers and lakes, where they feed and reproduce.

Photo by: Engbretson Eric

What eats sturgeon?

The sturgeon feeds on various benthic organisms and fish, and the composition of the diet depends on the age of the fish and the specific habitat. The diet of an adult sturgeon is 85% of protein foods, especially voracious fish become before spawning: they eat almost everything they can find at the bottom. These can be various crustaceans, mainly amphipods (rats of different legs or carapaces) and representatives of the branch branch group. The larvae of insects, tolkun mosquitoes and caddisfishes, as well as clams, shrimps, mussels, worms and leeches are eaten in large numbers. If the amount of protein food is limited, sturgeon eat algae. Fish diets include gerbil, anchovy, herring, sprat, sprat, gobies, white bream, perch, mullet and other small and medium sized fish. There were cases when large individuals of sturgeon successfully hunted wild ducks.

Sturgeon fry feed mainly on zooplankton (daphnia, cyclops, and Bosmina), but are able to eat very small crustaceans and worms. Young individuals eat insect larvae, snails, small shrimps and crustaceans. Many inedible particles, probably absorbed from oozy deposits, are often found in the stomachs of fry.

During the breeding season and after spawning, sturgeon practically ceases to eat or switches to plant food, but within a month the fish’s appetite is restored, and they are again being fed.

Sturgeon classification.

According to the database fishbase.org, there are 17 species of sturgeon (data from 10/2016):

  1. Acipenser baerii - Siberian sturgeon,
  2. Acipenser brevirostrum - stupid sturgeon,
  3. Acipenser dabryanus - Korean sturgeon,
  4. Acipenser fulvescens - Lake sturgeon,
  5. Acipenser gueldenstaedtii - Russian sturgeon,
  6. Acipenser medirostris - Green sturgeon (Pacific),
  7. Acipenser mikadoi - Sakhalin sturgeon,
  8. Acipenser naccarii - Adriatic sturgeon,
  9. Acipenser nudiventris - Thorn,
  10. Acipenser oxyrinchus - American Atlantic sturgeon,
  11. Acipenser persicus - Persian sturgeon,
  12. Acipenser ruthenus - Sterlet,
  13. Acipenser schrenckii - Amur sturgeon,
  14. Acipenser sinensis - Chinese sturgeon,
  15. Acipenser stellatus - Sevruga,
  16. Acipenser sturio - Atlantic sturgeon,
  17. Acipenser transmontanus - White sturgeon.

Fossil sturgeon species:

  1. Acipenser albertensis † - Campanian stage of the Upper Cretaceous - Early Paleocene 83.5–61.7 million years ago
  2. Acipenser eruciferus † - Campanian - Maastricht tiers of the Upper Cretaceous 83.5-65.5 million years ago
  3. Acipenser molassicus †
  4. Acipenser ornatus †
  5. Acipenser toliapicus † - Luteta stage of the Eocene 48.6–40.4 million years ago, Europe and northern Asia
  6. Acipenser tuberculosus †
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Types of sturgeon, photo and name.

The genus of sturgeon includes 17 species of fish, most of which are listed in the Red Book with the assigned status of endangered. Below is a description of some species.

  • Siberian sturgeon (latAcipenser baerii) - large fish up to 2 meters long. Sturgeon weighs up to 210 kg. Inside the species, 2 species are distinguished: the hot-nosed and blunt-nodged (ordinary) individuals. The general population of the Siberian sturgeon is divided into freshwater and semi-passage forms that inhabit the Siberian rivers from the Ob to the Kolyma, and also live in Lake Baikal and in eastern Kazakhstan in Lake Zaisan. Initially, the Siberian sturgeon was divided into 4 subspecies:
    • Yakut sterlet-shaped sturgeon (Latin Acipenser baerii chatys, Drjagin, 1948), called the Khatys, who lives in Khatanga, Lena, Yana and Indigirka,
    • Baikal sturgeon (Latin Acipenser baerii baicalensis, Nikolskii, 1896) inhabiting Lake Baikal and having a similar morphology with the North American sturgeon,
    • East Siberian (long-nosed) sturgeon (Latin Acipenser baerii stenorrhynchus, Nikolskii, 1896),
    • West Siberian sturgeon (Latin Acipenser baerii baerii, Brandt, 1869).

At the end of the 20th century, scientists proved that there are no significant differences between these subspecies, and the separation became unacceptable. The diet of the Siberian sturgeon includes crayfish, insect larvae (mainly caddisflies and tolkun mosquitoes), as well as mollusks and various species of small fish, especially Baikal broadleaf juveniles. Siberian sturgeon freely crossed with Siberian sterlet, and their offspring is called a bonfire. The Siberian sturgeon differs from the sterlet in a smaller number of lateral scutes (up to 50). The difference from the Russian sturgeon is in the presence of the Siberian species of gill stamens in the form of a fan and a sharper snout in some individuals.

Taken from the website: www.rybarskyrozcestnik.cz

  • White sturgeon (lat Acipenser transmontanus) - a very large sturgeon species, inferior in size only to beluga and kaluga, as well as the largest North American fish. Security status: causing the least concern. The informal name of the fish is the California white sturgeon. The fish has a rather slim body, and the length of the largest sturgeon was 6.1 m with a mass of 816 kg, although the average weight of the sturgeon usually does not exceed 10-20 kg. The dorsal row contains from 11 to 14 scutes, the side rows consist of 38-48, the abdominal scutes range from 9 to 12. The back and side surfaces are painted grayish, light olive or grayish-brown, the belly and bottom of the head are white. The sturgeon feeds on numerous mollusks, various crustaceans, lamprey and fish, including smelt. White sturgeon is a migratory fish living in Pacific waters off the western coast of North America from the Aleutian Islands located in the subarctic zone to the state of California. Spawning grounds are located in brackish estuaries of the rivers, some of the individuals pass far up into freshwaters. Regular migrations to rivers in these fish are not necessarily associated with spawning. The most numerous populations of California sturgeon are common off the coast, as well as in the inland waters of the states of Washington and Oregon, in southwestern Alaska, in the California bay of San Francisco and the deltas of the Sacramento and San Joaquin rivers. Dams erected on the Columbia and Snake rivers isolated part of the population in the river, and over time the fish acquired a freshwater form.

Photo author: Wald1siedel

  • Russian sturgeon (lat Acipenser gueldenstaedtii) - one of the very first objects of artificial breeding, which has a high value throughout the world for the exceptional gastronomic qualities of meat and caviar. Security status: on the verge of extinction. Has a checkpoint and a residential form. The Russian sturgeon differs from other sturgeon by its blunt short snout and antennae, which grow not near the mouth, but closer to the end of the snout. The maximum length of an adult Russian sturgeon is 2.36 m with a weight of 115 kg, but usually the mass of sturgeon does not exceed 12-24 kg. The average length is 1.45 m. The Russian sturgeon has a grayish-brown back, gray sides with a yellow tint and a whitish belly. In the dorsal row usually contains from 9 to 18 scutes, in the lateral rows from 30 to 50, in the abdominal not more than 7-12. Depending on the habitat, the ration of representatives of the species consists of crayfish (amphipods), mysids and worms. Fish diet includes sprat, herring, mullet and shemaya. Under natural conditions, the Russian sturgeon produces hybrid offspring with beluga, sterlet, stellate sturgeon and thorn. Russian sturgeon is found in almost all major waterways of Russia. The main habitat of sturgeon are the basins of the Caspian, Black and Azov seas. To spawn the Russian sturgeon goes to the Volga, Terek, Don, Kuban, Samur, Dnieper, Danube, Rioni, Mzymta, Psou and other rivers.

Photo author: Martin Chytrý

  • Amur sturgeonhe shrenka sturgeon (latAcipenser schrenckii, Acipenser multiscutatus) forms a freshwater (residential) and semi-passable forms, which are considered to be close relatives of Siberian sturgeon. But, unlike the Siberian sturgeon, the Amur species has gilllike stamens not fan-shaped, but smooth and have one vertex. Security status: on the verge of extinction. Amur sturgeon reaches 3 meters in length with a body weight of about 190 kg, but the average weight of sturgeon does not usually exceed 56-80 kg. Representatives of the species have a pointed snout of elongated shape, which can be up to half the length of the head. Dorsal sturgeon rows contain from 11 to 17 scutes, lateral from 32 to 47, abdominal from 7 to 14. Amur sturgeon eat caddis larvae and mayflies, various crustaceans, lamprey larvae and small fish. Sturgeon lives in the Amur River basin, from the lower reaches and higher, to Shilka and Argun, during the breeding season, the shoals go upriver to the area of ​​Nikolaevsk-on-Amur.

Author photo: Lukina Elena

  • Atlantic sturgeon (lat Acipenser sturio) - a very large representative of the genus, the maximum size of which can reach 6 meters. The maximum registered weight of fish is 400 kg. The beetles of the Atlantic sturgeon are much larger than those of the other sturgeon, and on the tail there are 3 pairs of large fused shields. On the back of the sturgeon, the oblique rows of small, diamond-shaped plaques and from 9 to 16 large light scutes are well pronounced. In the side rows there are from 24 to 40 scutes, on the belly from 8 to 14. The back of the fish is grayish-olive in color, the sides are much lighter, the belly is white. The sturgeon food includes small fish (anchovies, capelin and gerbil), as well as worms, crustaceans and mollusks. Initially, the Atlantic sturgeon was found off the coast of Europe in the Baltic, North, Mediterranean and Black seas, as well as off the North American coast from Hudson Bay to the state of South Carolina. To spawn shoals of fish were sent to the river Svir, Volkhov, Elbe, Oder, Danube. Despite the impressive historical habitat, the Atlantic sturgeon is on the verge of extinction and in most areas almost exterminated. Currently, the Atlantic sturgeon is found only in the Black Sea and the Bay of Biscay, where no more than 300 individuals live. According to foreign sources, a small amount of Atlantic sturgeon is found only in the Garonne River in France.

Taken from the site: itsnature.org

  • Lake Sturgeon (lat Acipenser fulvescens) - a large representative of the genus, biologically close species with blunt-necked sturgeon. The maximum recorded length of adult fish is 2.74 m with a body weight of 125 kg. The body is painted in black with gray or greenish-brown tones, the belly is white or yellow. Basically, lake sturgeon feed on all sorts of bottom organisms, fish is consumed to a lesser extent. Lake Sturgeon is a North American and Canadian resident living in the Great Lakes system, Lake Winnipeg, as well as in the Mississippi, Saskatchewan and St. Lawrence river basins. Security status: causing the least concern.

Photo by: Fungus Guy

  • Sakhalin sturgeon (lat Acipenser mikadoi) - the most rare and rather poorly studied species, according to biological features identical with green (Pacific) sturgeon. The average length of adult specimens reaches 1.5-1.7 m with a weight of 35-45 kg, the largest individuals grow up to 2 m in length and weigh about 60 kg. Adult individuals are distinguished by a large, blunted snout. Окрас сахалинского осетра — зеленовато-оливковый, на спине располагаются от 8 до 10 жучек, по бокам от 27 до 31, на брюхе от 6 до 8. Питание сахалинского осетра состоит из различных обитателей илистого дна: улиток и прочих моллюсков, личинок насекомых, мелких креветок, ракообразных, а также некрупной рыбы. Ареал вида охватывает холодные воды Японского, Охотского морей и Татарский пролив, на нерест рыба уходит в реку Тумнин Хабаровского края.

Взято с сайта: www.ichthyo.ru

  • Персидский осетрhe южно-каспийский or куринский осетр (lat Acipenser persicus) — проходной вид, близкий родственник русского осетра. Находится на грани исчезновения. Максимальный размер осетра составляет 2,42 м при весе 70 кг. The representatives of the species have a large, long, slightly curved down snout and gray-blue coloring of the back, with blue sides with a metallic sheen. Also, the Persian sturgeon differs from other species in a smaller number of scutes in each row. The diet of the South Caspian sturgeon consists mainly of benthos and small fish. The natural habitat of fish is the middle and southern regions of the Caspian Sea, a small proportion of the population inhabits the northern regions of the Caspian Sea and is found off the Black Sea coast. The main spawning grounds are located in the Volga, Ural, Kura, Inguri and Rioni rivers.

Author photo: Dorafshan, S.

  • Sterlet (lat Acipenser ruthenus) - the average representative of the genus sturgeon differs from other sturgeon in early puberty: males are ready for breeding at the age of 4-5 years, females are 7-8 years old. Another difference between sturgeon and other sturgeon is in its fringed antennae and a large number of side scutes: usually more than 50. Sterlet is a freshwater fish, but there are a small number of semi-passage forms. The maximum length of the sterlet reaches 1.25 m, and its mass does not exceed 16 kg. The average size is 40-60 cm. Sterlet is acute and blunt-toed, and its color varies from brown with gray to brown, the belly is white with yellowness. Most of the sterlet's diet consists of insect larvae, leeches and other benthic organisms, the fish are eaten to a lesser extent. Valuable hybrid form of sterlet and beluga - bester, is a popular object of economic growth. The natural habitat of the sterlet runs in the rivers of the Caspian, Black, Azov and Baltic Seas, is found in rivers such as the Dnieper, Don, Yenisei, Ob, Irtysh, Volga with its tributaries, Kuban, Sura, Ural, upper and middle Kama, previously It was also found in the Ladoga and Onega lakes. Some of the population was resettled in the Neman, Western Dvina, Pechora, Onega, Amur, Mezen, Oka and a number of artificial reservoirs, though fish did not take root everywhere. Security status: vulnerable view.

Photo by: weisserstier

  • Stellate sturgeon (lat Acipenser stellatus) - sturgeon species, closely related to sterlet and thorn. Sevruga is a large fish reaching 2.2 m in length with a mass of about 80 kg. The stellate sturgeon has an elongated, narrow, slightly flattened snout, amounting to 65% of the length of the head. The rows of dorsal scutes contain from 11 to 14 elements, in the side rows there are from 30 to 36, on the belly from 10 to 11. The surface of the back is black and brown, the sides are much lighter, the belly is usually white. The diet of stellate sturgeon consists of crustaceans and mysids, various worms, as well as small species of fish. Sevruga lives in the basins of the Caspian, Azov and Black Seas, sometimes fish are found in the Adriatic and Aegean Seas. During the breeding season, sturgeon goes to Volga, Ural, Kuru, Kuban, Don, Dnieper, Southern Bug, Inguri and Kodori.

Author photo: Lubomír Klátil

Spawning of sturgeon.

With the exception of certain species, puberty in sturgeon occurs rather late: the males are ready for breeding at the age of 5 to 18 years, the females mature at the age of 8 to 21 years. The time of maturation depends on the range: the north to live fish, the later they are ready for reproduction. Reproduction does not occur every year. Spawning of sturgeon females occurs every 3-5 years, males spawn more often. After breeding (spawning), sturgeon does not die, unlike some other species of fish.

The spawning migration of migratory and semi-migratory species of sturgeon is significantly extended over time and lasts from early spring to November, and its peak occurs in the middle of summer. Early migratory sturgeon (spring species) spawn in the same year, winter forms of sturgeon hibernate in rivers and spawn the following spring.

For spawning, sturgeon chooses rivers with a strong current (up to 1-1.5 m / s) and a rocky or pebbly bottom, less often sandy. Reproduction is not observed in saline or stagnant water. Spawning occurs at a depth of 4 to 25 m at a water temperature of + 15 to +20 degrees, depending on the range. An increase in temperature adversely affects the development of embryos, significantly reducing the number of hatched larvae, and when the water temperature is above 22 degrees, sturgeon caviar dies.

Spawning is performed in the crevices of the bottom or cracks of large stones, sometimes in well-insignificant sections of the coast flooded with spring floods. Sturgeon is one of the most prolific fish: large females are able to lay up to several million eggs, making up about 25% of their body weight. The largest caviar is of Pacific (green) sturgeon, reaching a diameter of 4.5 mm, and the average diameter of the eggs is 2-3 mm. At the same time, 1 g of sturgeon caviar contains about 100 eggs.

Taken from the site: salmanayashi.id

Caviar of sturgeon is sticky and keeps well on the substrate, where it was deposited. When the water temperature is about +20 degrees, embryonic development lasts about 2-4 days. The duration of the incubation period can be as long as 10 days. The weight of proklyuvlivshihsya larvae is about 10 g with a length of 0.8-1.1 cm. New-born sturgeons see little and swim poorly, therefore, at first they hide in shelters under stones.

Photo author: Martin Chytrý

The large yolk sac surrounding the sturgeon larva and serving for it is completely absorbed in 10-14 days. During this time, the fry grow to 1.6-2 cm and start active feeding: they usually eat planktonic crustaceans (daphnia, cyclops), and then move on to mysyd, gammarid, oligochad and chironomid larvae. Now the sturgeon fry acquire the features of adults and swim quite well. Juveniles of sturgeon migratory species swim in the pre-drainage area of ​​the river, where they live for some time. Fry of some species (spike, Russian sturgeon) linger in fresh river water, where they live for a year and sometimes a little longer. Thus, the first year of life of the sturgeon fry is carried out in fresh water or on the border of fresh and salt water, since the concentrated salt water of the seas is destructive for young sturgeons.

How long does sturgeon grow?

The sturgeon grows rather slowly: large species of sturgeon at the age of 2 years old grow only up to 28-35 cm in length, by the age of 4, the growth is 2 times. At 8 years of age, the sturgeon has a body length of about 1 m, and only by the age of 12 it reaches average sizes for the species.

Photo author: U.S. Fish and Wildlife Service Southeast Region

Sturgeon - benefit and harm.

The calorific value of sturgeon is 160 Kcal per 100 g.

Sturgeon contains easily digestible proteins, due to which the product is digested very quickly and is often included in various diets. The composition of sturgeon meat is rich in rare useful acids, including glutamic acid, as well as vitamins of group B, C, A and PP. Delicious meat of sturgeon contains a mass of useful macro- and microelements: potassium, phosphorus, calcium, magnesium, sodium, chlorine, iron, chromium, molybdenum, nickel, iodine and fluorine.

Sturgeon caviar is saturated with beneficial proteins and lipids, and its caloric content is about 200 Kcal, so the product is recommended for people who have been weakened after a serious illness and underwent aggressive treatment.

Regular consumption of sturgeon meat, which contains beneficial fatty acids, has a beneficial effect on blood vessels and heart muscle, reducing the level of cholesterol in the blood and reducing the risk of myocardial infarction. The product has a positive effect on the growth and strengthening of bone tissue, and also promotes skin regeneration.

Fisheries.

At the beginning of the 20th century, the sturgeon fishery in Russia had a grand scale, and the number of fish caught was greater than in all countries of the world combined. Therefore, despite the extraordinary fecundity of sturgeon, the population size has declined dramatically and since the beginning of the XXI century, fishing for almost all species of sturgeon has been completely banned in Russia.

The structure of sturgeon

This type of fish has a very interesting structure, which is not to be confused with any other. They do not have a skeletal bone structure, the body is supported by cartilage and rows of bone plates located outside. On the head - the same coating, it resembles the armor of an ancient knight.

The nose of this fish is called a snout and can have two forms:

  • narrow, elongated, conical (genus Belug, sturgeon),
  • spade (genus of shovelnose), nose-shovel.

The fish lives on the bottom of reservoirs, therefore has a flat stomach. At the bottom of the head is a mouth with fleshy lips, which it pulls out with a straw and sucks the near-bottom food, no teeth. On the upper part of the nose, in front of the mouth, grow a mustache, with the help of which the sturgeon finds food at the bottom. It feeds in shallow water in places with a high content of humus. There are many mollusks, worms, crustaceans. Loves to catch and small fish.

The structure of sturgeon.

The color of the sturgeon is mainly gray with brownish sides, belly light. Even in ancient times, this fish began to be called red. Red means the best, delicious, with excellent nutritional properties. Her meat is white or slightly yellowish.

Types of sturgeon

In terms of habitat, representatives of the sturgeon family are divided into two types:

  1. Passing fish are fish that live in salt water. and they spawn in freshwater rivers (stellate sturgeon, beluga, Russian and Atlantic sturgeon, and spike).
  2. Impassable - freshwater sturgeon, they live in rivers (sterlet) or lakes (Baikal sturgeon) and spawn in rivers.

The largest representative of sturgeon is the beluga, in the adult state it reaches 6 m and weighs up to 1 ton.

Beluga can be considered the largest freshwater fish, the weight of some of the caught specimens reached one and a half tons.

The smallest is sterlet. She grows up to 1 meter and weighs 15-16 kg in adult condition.

How old are sturgeon fish in nature? Under favorable conditions of habitation and absence of poaching, the age of Beluga can reach 100 years, sturgeon - 50 years, stellate sturgeon melts to 30 years.

Habitats

Nature arranged that This fish lives in both salt and fresh water. But it lays caviar only in clean freshwater rivers. It lives in North America, Europe, in the north of Southeast Asia. The largest population inhabits water bodies of Russia, where the most widespread are:

  • Siberian sturgeon - the mighty rivers of Siberia and the deepest lake Baikal,
  • Russian sturgeon - the waters of the Volga, the Urals, the Danube, the Caspian Sea,
  • Kaluga - the Amur River,
  • Beluga - Caspian, Black Sea.
  • Sterlet, Sevruga - Black Sea, Azov, Caspian Sea.

Sterlet - inhabitant of the Black, Azov and Caspian Seas.

Commercial fishing of sturgeon was not long ago distributed in the Caspian. However, due to river pollution, a sharp increase in poaching in recent years, it has declined significantly, and in many places has stopped altogether.

Many species of sturgeon are listed in the International Red Book and the Red Book of Russia. Their fishing is prohibited.

Breeding red fish

The construction of power plants on the rivers, the violation of the environment has significantly reduced the number of this fish. Most of its modern reproduction takes place in fishing factories and private fish farms.

At fish factories they mainly breed beluga, stellate sturgeon, thorn and sturgeon.

Adult fish are caught in rivers, brought to the factory in special containers, get caviar from them. From it in the incubation workshops appear the larvae. They are seated in pools and grown to the state of fry 1.5 - 3 cm long in clean running water.

Breeding sturgeon fish is considered a promising business.

What is the value of sturgeon?

Caviar and meat of all kinds of sturgeon was always in the price. Among the ancient peoples, it was served on the table only by kings, emperors and the highest nobility.

The protein of meat of these fish is completely absorbed by the body. The fish is rich in the whole set of vitamins and microelements, amino acids, necessary for nutrition. It contains large amounts of fluoride. It is necessary for the growth of bones. Therefore, it is very useful for children to eat caviar and sturgeon meat.

The most valuable fish glue is made of an air bubble. It is used in medicine, in printing when printing books, by jewelers for sticking gold leaf, in the restoration of ancient paintings.

To restore the livestock of these valuable fish, it is necessary to study their living conditions and habits, to treat nature carefully, to comply with all the norms of catching.

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