Sturgeons: a list of family members, names and characteristics where they are found
Sturgeons have long been valued by people due to the extraordinary taste of the most delicate meat and the unique composition of caviar. This is confirmed by archaeological excavations. They testify that as early as the sixth century, beluga up to 6 meters long were mined in the Moscow River. The habitat of sturgeon is considered to be North America and Eurasia. For 170 million years, they have adapted to a temperate climate and easily endure lower temperatures.
What kind of fish is this
Today many similar sturgeons are known. Sturgeons have common characteristics and a number of differences.
Where does she live
Sturgeons include different species - anadromous, freshwater, semi-anadromous. Anadromous are individuals that live in the seas and rivers. During reproduction, they migrate from the sea to the river. The reverse situation is also possible, but it is observed much less frequently. Semi-anadromous fish live in coastal marine areas. They can also be found in lakes. At the same time, such individuals move to spawn in the lower reaches of the rivers.
Under natural conditions, sturgeons live in the waters of the northern temperate zone of Europe. In addition, they live in northern Asia and North America. For many years of evolution, the sturgeon has perfectly adapted to life in a temperate climate. This fish can withstand a drop in water temperature and can go without food for a long time.
Sturgeons are bottom-dwelling species that live at depths up to 100 meters. Anadromous varieties live along the coasts of the seas and oceans, but during the breeding season they move to fresh rivers.When the fish enter there, they swim against the current. In this case, individuals overcome significant distances. After spawning is completed, the fish move back to the sea in schools.
Semi-anadromous varieties prefer s alty coastal areas of the seas and oceans. At the same time, they move to the river mouths for spawning, but do not rise upstream. Many freshwater varieties of sturgeon do not make long migrations. They prefer a sedentary lifestyle and live in rivers and lakes. In the same place, fish find food for themselves and multiply.
Expert opinionZarechny Maxim ValerievichAgronomist with 12 years of experience. Our best gardening expert.Ask a QuestionSpawning of such individuals occurs in spring and summer. However, their migration to spawning grounds occurs at different time intervals. Because of this, sturgeons are divided into seasonal races - spring and winter. The first category moves to the spawning area before spawning. This happens with the onset of spring.Winter varieties migrate in autumn - before the eggs ripen.Sturgeons live in areas where there are no other large predators. Because they have almost no enemies in nature. The fish that are encountered on the way of sturgeons are not able to gnaw through their bone plates. That's why no one attacks them. Sturgeons should only beware of people. For several centuries, people have been actively harvesting sturgeon to obtain he althy meat and valuable black caviar.
It should be taken into account that sturgeons are considered to be very demanding on environmental conditions. When fish enters a dirty pond, it can pick up a large number of infections. Therefore, breeding sturgeons in artificial conditions is considered a very expensive occupation. It involves the installation of special equipment.
What does it eat
The basis of the sturgeon diet is bottom organisms and fish. At the same time, their age and habitat directly affect the nutrition of such individuals:
- Fry eat zooplankton. In their diet there are bosminamia, cyclops, daphnia. However, sometimes these individuals also consume small crustaceans and worms.
- Young fish eat insect larvae. They also eat snails, small shrimp and crustaceans. It is worth noting that inedible fragments can also be found in the stomachs of fry. Most likely, they suck them out of the muddy bottom.
- Adults mostly eat protein foods. They become most voracious before spawning. During this period, sturgeons eat almost everything they can find at the bottom, including various crustaceans and representatives of the cladocerans order. These individuals often eat pusher mosquitoes, insect larvae, and worms. Mussels, shrimps and leeches may also be present in their diet. Often, adult fish feed on molluscs and caddis flies.
If sturgeons don't get enough protein, they can eat algae. As for the fish diet, it includes herring, gerbil, gobies. Also, sturgeons are happy to absorb mullet, pike perch, sprat and many types of small and medium-sized fish.
During spawning and after the end of breeding, sturgeons stop feeding and begin to absorb vegetation. It takes about a month to recover individuals. Then their appetite returns. Then the fish starts looking again for food that will help them survive.
How long does it live
When puberty, sturgeons begin to spawn. In most cases, reproduction begins in the spring and ends in November. The peak of this period is the middle of summer. For spawning, fish prefer rivers, the temperature parameters of which are + 15-20 degrees. If the indicators are exceeded, the probability of death of eggs is high.
Females go to spawn at intervals of 3-5 years. This happens more often in males. After the breeding season is over, sturgeons do not die, as happens with many other fish.
Immediately after birth, sturgeons hide under stones. This is due to the fact that they are not very good swimmers and have poor eyesight. After 10-12 days, the fry reach a length of 2 centimeters. They actively absorb food, swim well and resemble adults in appearance.
During the first year of life, young fish remain in fresh water. They can also live on the border with s alt water. The fact is that sea water for such fish is considered deadly.
Sturgeons are characterized by rather slow development. Large varieties reach 28-35 centimeters by the age of 2, and about 70 by 4. Only by the age of 12 do these fish reach medium sizes.
At the same time, the life span of sturgeons depends on their variety:
- stellate sturgeon lives 30 years;
- sturgeon can live up to 50 years;
- beluga lives to be 100 years old.
It is worth considering that the life expectancy of sturgeon depends on a number of factors. First of all, this parameter is influenced by seasonal water temperature. Also of great importance is the pollution of the reservoir.
What a sturgeon looks like
The sturgeon is characterized by an elongated spindle-shaped body, which covers a row of bony spines. It is noteworthy that representatives of this family do not have vertebrae. The structure of the skeleton includes only cartilaginous tissues. At the same time, the chord is preserved in fish for life.
In the lower part of the spine is a large swim bladder. It is attached to the dorsal part of the esophagus and makes it possible to descend to a depth of up to 100 meters. Sturgeons have 4 main gill openings, which have evolved into spiracles. Within these elements there are up to 45 gill rakers. As water is drawn into the gills through the spray, sturgeons absorb the oxygen contained in it.
These individuals are characterized by a small elongated head. It may have a sharp or slightly blunt spatulate or cone-shaped snout.At the end of the head are two pairs of smooth whiskers, which represent the organ of touch. Fish use them to navigate in space and search for food by feeling the bottom of the reservoir. The mouth is located at the bottom of the head. While eating, the fish protrudes its lips, which allows it to grab bottom organisms. The fry have underdeveloped teeth. As they grow, they disappear.
The color of the fish is largely influenced by the habitat. Experts are able to determine the river from which the sturgeon was caught by eye. Sturgeons are characterized by a light belly. It may be white or yellowish. The lower fin has the same color. The back and sides of the sturgeon are distinguished by a dark shade. It can be blue or greenish.
Body structure
Sturgeons are characterized by a rather interesting body structure, which makes it possible to distinguish them from other fish.
Scales
The torso of the representatives of the Sturgeon family is covered not with scales, but with skin. It has 5 rows of shields, which are arranged longitudinally. The line that runs along the back forms a sharp keel. Its structure includes 10-18 bugs. There are 25-26 scutes in the lateral rows, and 7-15 on the belly. The specific number of bugs is determined by the species. Bone plates with sharp spikes resemble a shell. It provides sturgeons with reliable protection against large predators.
Liver
The liver of all varieties of sturgeon accumulates trace elements. Therefore, it is important to consider in which reservoir they are found. In adverse conditions, valuable fish accumulate harmful substances. Despite this, there are many important elements in the sturgeon liver. These include vitamins of groups B, D, C, A. The product is also rich in phosphorus and potassium. Therefore, sturgeon liver should be consumed by people who adhere to a dietary diet.
Fins
The appearance of the fins depends on their varieties. The tail element promotes forward movement. It has a long top and an asymmetric structure where the end of the spine comes in.
The dorsal and anal fins are used as a keel. With their help, the fish holds the body upright. The dorsal fin is characterized by 25-50 soft rays, which are shifted towards the tail. Anal fin includes 17-32 rays. It starts under the end of the dorsal.
With the help of the pectoral and ventral fins, the fish can turn, rise, fall. It is worth noting that the chest elements seem stiffer. In this case, the front beam resembles a spike. Experienced fishermen are able to determine the age of the fish by its cut.
About sturgeon meat
In Rus', representatives of the sturgeon family were classified as red fish. In fact, their meat is white, pinkish yellow or light pink in color. In any case, it is very he althy.
Sturgeon contains a large amount of proteins that are easily digestible. Thanks to this, the product is quickly digested. No wonder nutritionists recommend it. Sturgeon meat contains a large amount of valuable acids, including glutamic acid. It also contains vitamins of groups B, C, PP, A.
Sturgeon meat is considered a delicacy. It includes many valuable micro and macro elements. Among them, it is worth highlighting calcium, iodine, potassium. Sturgeon is also rich in chromium, sodium, and iron. 100 grams of sturgeon contains 160 kilocalories. The energy value of sturgeon caviar is 200 kilocalories. The product contains many proteins and lipids. Caviar is useful for people who are weakened after serious illnesses or have undergone aggressive therapy.
Due to the high content of fatty acids, sturgeon meat helps to strengthen the heart and blood vessels. It lowers blood cholesterol levels and minimizes the risk of myocardial infarction. Sturgeon caviar has a good effect on the development of bones and normalizes the restoration of the skin.
With the regular use of sturgeon meat and caviar, it is possible to improve the he alth and well-being of a person. Sturgeon fat normalizes the functioning of the brain. In addition, fish helps to cope with stress and improves the prognosis in the treatment of depression.
The most valuable is the caviar of stellate sturgeon, Russian sturgeon and beluga. The product has a different color and size. At the same time, it is important to take into account that caviar and sturgeon itself can be infected with botulism pathogens. Therefore, fish can only be purchased from reliable suppliers. In addition, the goods must be carefully examined before purchase.
People who are obese and diabetic should use this fish with caution. It is advisable to consult your doctor beforehand.
Popular species
Today, many species of sturgeon are known, each of which is characterized by certain characteristics. Below is a list of the most popular varieties.
Russian sturgeon
This fish is found in the basins of different seas - Azov, Black and Caspian. The Russian sturgeon is predominantly an anadromous species. Freshwater individuals live in artificially stocked reservoirs. There is also a Russian sturgeon of a residential form, which inhabits the lower reaches of the Volga. However, today it is on the verge of extinction.
Russian sturgeon lives up to 46 years. The average weight of the fish is no more than 25 kilograms. In favorable conditions, individuals can reach a length of 2.3 meters. At the same time, their weight is up to 115 kilograms. However, such individuals are extremely rare.
This species of sturgeon is characterized by constant spawning and feeding movements. Sexual maturity of the Russian sturgeon occurs at 8-13 years. Females are ready to breed at 8-20 years old. To lay eggs, individuals need to enter rivers.
If a fish starts migrating in spring or in the first half of summer, it spawns in the same year. When entering the rivers in autumn, reproduction begins only in the spring of next year. In this case, the water temperature should be + 9-15 degrees. After spawning, the fish swims back into the sea. After switching to a mixed diet, juveniles begin to move en masse to the sea.
Depending on the habitat, the diet of this fish may be based on amphipods, mysids and worms. Also, Russian sturgeon actively absorbs fish. It feeds on herring, sprat, shemay and mullet. In nature, these individuals can produce hybrid offspring with other members of the family. These include beluga, sterlet, stellate sturgeon.
Sterlet
The natural habitat of this species of sturgeon is considered to be the rivers of the basin of some seas - the Azov, Black, B altic. Sterlet can be found in the Dnieper, Ural, Yenisei. It is also found in the Volga, Don, Irtysh.Previously, these individuals could be caught in the Ladoga and Onega lakes. The fish is now a vulnerable species.
The sterlet is medium in size. Her puberty begins quite early. Males are ready to breed at the age of 4-5 years. In females, this period begins at 7-8 years. The key difference between the sterlet and other sturgeon species is the presence of a fringed mustache. They also have many lateral bugs. Their number exceeds 50.
This fish belongs to freshwater. However, there are also a number of semi-anadromous varieties. The maximum length of a sterlet is 1.25 meters. At the same time, its weight reaches 16 kilograms. On average, the fish does not exceed 40-60 centimeters. It is characterized by a sharp or blunt snout. As for the color, it is brown or brown-gray. The fish has a white belly with a yellowish tint.
The sterlet feeds on insect larvae and leeches. It can also absorb benthic organisms and some small fish. Of great value is the hybrid of sterlet with beluga. It's called bester.
Schrenk (Amur sturgeon)
This fish lives in the Amur basin. At the same time, it moves to Nikolaevsk-on-Amur for spawning. Shrenka lives in fast moving water. In summer, it moves to floodplain lakes. In winter, the Amur sturgeon chooses deep places, which are distinguished by a rocky bed.
The breeding season starts at 9-14 years of age. By this time, the length of the fish reaches 115 centimeters, and the weight is about 8 kilograms. Spawning begins at the end of May and continues until the end of June or mid-July. Shrenka chooses pebble shoals for breeding, descending to a depth of 2-3 meters. Amur sturgeon spawns every 4 years.
This fish is characterized by a spindle-shaped body, which is covered with small comb-like growths.Below the lateral bugs are small plates that resemble stars. The snout has a conical shape and is pointed. It is complemented by 4 flattened mustaches, which are covered with an almost imperceptible fringe. At the bottom of the head is a small cross-shaped mouth.
The body is yellow-gray or black. In this case, the abdomen and sides have a light shade. Shrenka's diet is based on insect larvae, crustaceans, and mollusks. She also eats small fish.
Kaluga
This name is used to designate the largest representative of sturgeons. The fish can reach a length of 5.5 meters. Moreover, its weight is 1 ton. Kaluga lives up to 55 years. Her body is characterized by a heterogeneous gray-green color. The fish has a white belly. At the same time, the back and sides have a darker shade.
Kaluga has a cone-shaped snout. It is pointed and shortened. The mouth resembles a large semicircle in appearance. The body is covered with bony plates. Kaluga is found in Argun, Shilka, Amur. She eats minnows, chum salmon and pink salmon.
Stellate sturgeon
This fish is considered a prominent representative of the sturgeon breed. It is characterized by an elongated, flattened snout. The antennae are devoid of fringe, and the body is covered with bugs and plates in the form of stars.
Stellate sturgeon is found in different seas - Black, Azov, Caspian. It can dive up to 100 meters deep. In length, this individual reaches 2 meters. Moreover, its weight is 80 kilograms. The fish has a white belly. At the same time, the back and sides are distinguished by a blue-black color. The diet of stellate sturgeon is based on small fish - gobies, herring. She also eats worms, shellfish, crabs.
Why the population has declined
Even in the seventeenth-nineteenth centuries, up to 50 thousand tons of sturgeon were caught in the Caspian basin.At the turn of the nineteenth and twentieth centuries, production decreased to 29 thousand tons. In 2007, commercial fishing was completely banned in the Caspian Sea. Such a measure was associated with the need to preserve the population of valuable fish.
Ichthyologists identify 2 main reasons for the decrease in the number of sturgeons of different names:
- poaching has increased by a third since the beginning of this century;
- reduction of spawning areas - due to the active development of the economy in the river basins.
Sturgeon is a unique fish that is considered very popular. All representatives of this family have unusually valuable meat, and therefore are considered very popular.
