Sturgeons include a certain group of fish that represent the sturgeon family. Many people, when they hear the word sturgeon, understand the meat and caviar of this family, which have always been and are valued in cooking. Since ancient times, this fish has been associated with wealth, since its meat and caviar have always been present on the tables of nobles and other elites. Nowadays, sturgeon is considered a very rare fish, so specialists from many countries are making a lot of efforts to preserve and increase sturgeon populations around the world.
Sturgeon fish: description
This family is distinguished by its elongated body and represents the most ancient cartilaginous fish on the planet. The ancestors of the modern sturgeon family inhabited many rivers even during the period of dinosaurs. This is evidenced by animal fossils that have been found by scientists. According to scientists, these fish skeletons are approximately 80 million years old.
Appearance
As a rule, the body length of adult individuals reaches 2 meters, with a weight of 50 to 80 kilograms. At one time, a sturgeon was caught, about 8 meters long and weighing more than 800 kilograms. The body is spindle-shaped, covered with scales, bone growths, as well as plates that represent fused thickened scales. On the body of the fish there are 5 such rows located along the body. Two such rows are located on the belly, and the rest, one each, on the back and sides. The number of plates depends on the specific type of sturgeon.
Interesting to know! Like any other fish, the body color of sturgeons depends on their habitat, so the shade of sturgeons can be brown, gray or sand. The belly of this fish is light, and the back is either green or olive in color.
Sturgeons have quite sensitive antennae, with the help of which the fish probes the bottom and finds food for itself. The mouth of sturgeons is not large and toothless. It is located at the bottom of the pointed part of the muzzle. After birth, young individuals still have teeth, but as they grow older, they wear down. Sturgeons have fairly hard fins, a large swim bladder, and two pairs of gills. The skeleton of this fish does not contain bone tissue and consists of cartilaginous tissue, and instead of a spine there is a notochord.
Behavior and lifestyle
Sturgeon can be found at depths of up to 100 meters, while they lead a bottom-dwelling lifestyle, where they find food for themselves. These fish are adapted to living in cold water environments, as well as to long periods of fasting. Due to the behavioral characteristics of the sturgeon, they are divided into:
- On migratory species, which for their livelihoods choose coastal, slightly saline waters of the seas and oceans within the estuaries of rivers. Before spawning or for wintering, migratory sturgeon species rise to the upper reaches of rivers, covering impressive distances.
- On semi-anadromous species, which do not make significant migrations and reproduce directly at river mouths.
- On freshwater, for which a distinctive feature is a sedentary lifestyle.
Lifespan
Sturgeon can live from 40 to 60 years, while beluga can overcome the 100-year barrier, Russian sturgeon can live for half a century, and stellate sturgeon and sterlet live a maximum of 30 years. The life expectancy of sturgeons is influenced by many factors, including natural ones, associated with seasonal fluctuations in water temperature, as well as anthropogenic ones, in the form of pollution of seas and oceans.
World's Largest Fish Caught # Beluga Sturgeon 1490 kg
How is it different from other fish?
Sturgeon, beluga, sterlet, kaluga and stellate sturgeon belong to the same family - sturgeon. Therefore, there is a lot in common between them, which confuses both fishermen and buyers, who cannot always immediately distinguish what kind of fish is in front of them.
From beluga
Beluga is a fairly large fish, its length reaches about 9 meters, and its body weight is 60 kilograms.
Beluga meat is much coarser than sturgeon, whose meat is tender and juicy.
The difference is also noticeable in the size of the head. In the beluga it is short, and the stigma and tail are not too elongated.
From Kaluga
The sturgeon, unlike the kaluga, has short and not very pronounced mustaches. In addition, Kaluga has bony protrusions along its body.
Sturgeon is slightly larger than kaluga. The length of the first fish is 6 meters, and the length of the second fish is 5 meters.
The head of the kaluga, like that of the sturgeon, is long, but not too pointed.
In addition, sturgeon meat is fattier than that of kaluga.
From stellate sturgeon
Sevruga differs from sturgeon in all respects. The first fish has a longer nose and a dagger-like shape. The mustache is short and smooth, does not reach the mouth, the forehead is convex, the lower lip is not sufficiently developed. The body is elongated. There are dense shields on both sides and on the back. The body of the stellate sturgeon has a black-blue sheen, the sides are light, and the back is dark. There is a white stripe on the abdomen.
Stellate sturgeon also differs from sturgeon in size. It weighs no more than 6 kilograms, and the length of the stellate sturgeon’s body is approximately 1.5 meters.
From sterlet
The difference between sturgeon and sterlet is noticeable in everything:
- All fish belonging to the sturgeon genus are called sturgeon. Sterlet is considered a narrower definition of fish.
- The body size of the sterlet is very small. The body length reaches only 1 meter, and the weight is about 3 kilograms. The size of the sturgeon is 6 meters, and its body weight is 16 kilograms.
- The sterlet has a sharp and long nose, a small and narrow head, and has fringed antennae. The sturgeon, on the contrary, has a short nose and a wide head.
- The sterlet has many bugs on its sides (70 pieces), but the sturgeon has no more than 50 of them. The first fish has sharp spines on its back, while the sturgeon has a smoother body.
- Sturgeon can migrate from sea waters to river waters for the purpose of reproduction. Sterlet adheres to a sedentary lifestyle and prefers to spawn where it lives, that is, in rivers.
- Sturgeon caviar is greenish and large, while sterlet caviar is small and not very much.
- Sterlet meat is fattier and juicier than sturgeon.
From the sterlet
Sterlet differs from sturgeon in many ways. Her head is triangular and large. The lower lip bifurcates. The eyes are small and protruding.
On the head there are bone scutes that are fused together. The dorsal fin is shifted towards the tail.
The body is grayish-brown. There may also be places on the body with a light yellow color. The ventral region is lighter than the dorsal region.
Types of sturgeon with photos and names
To date, 17 species of sturgeon are known, and most of them are listed in the Red Book. The most common types include:
- Russian sturgeon has an excellent taste, and both meat and caviar are highly valued. Nowadays, this species of sturgeon is on the verge of extinction. This species of sturgeon has antennae growing at the end of its snout, but not around the mouth. It lives mainly in the Caspian, Black and Azov seas, as well as in the basins of these seas, or rather in the rivers flowing into these seas. There are both anadromous and sedentary species. Adult Russian sturgeon, as a rule, weigh no more than 25 kilograms. The bodies of these fish are distinguished by brown and gray tones, while the belly is always light. The diet of the Russian sturgeon includes fish, worms, crustaceans and other food items that live at the bottom of reservoirs. It can interbreed with other species of sturgeon such as sterlet and stellate sturgeon.
- Kaluga , as a rule, lives in the Far East. It differs from the family in that its back is green, its mustache is somewhat larger compared to other species, and its body is covered with several rows of bony scales, with points at the end. It feeds on everything it can get while living in the water. It spawns once every 5 years, and the number of eggs can be more than 1 million.
- The sterlet is characterized by the presence of antennae with a long fringe, as well as a large number of bone growths in the form of plates. Sterlet is different in that it is ready to spawn much earlier than other species. Sterlet is a freshwater sturgeon species. Adults reach a length of up to 0.5 meters and can weigh up to 50 kilograms. Considered a vulnerable species. The sterlet's diet includes insect larvae, leeches, and various benthic organisms; although fish is consumed, it is rare. Bester is a hybrid of sterlet and beluga. Raised artificially for meat and caviar. It is found in seas such as the Caspian, Black, Azov and Baltic, as well as in their basins.
- The Amur sturgeon (Schrenk's sturgeon) represents both a freshwater and semi-anadromous form and is a close relative of the Siberian sturgeon. The gill rakers are smooth and distinguished by the presence of 1 apex. Currently, it is also on the verge of extinction. It grows up to 3 meters in length and can weigh almost 200 kilograms, while the average weight of sturgeon is within 80 kilograms. It is also distinguished by the presence of an elongated snout, which occupies almost half the length of the fish’s body. The Amur sturgeon feeds on caddis flies, mayflies, various crustaceans, lamprey larvae and small fish. The habitat extends to the Amur River and its basin. During the breeding season it appears within Nikolaevsk-on-Amur.
- Sevruga represents the anadromous sturgeon, which are close relatives of the sterlet and thorn. It grows more than 2 meters in length and weighs around 80 kilograms. Stellate sturgeon differs from other representatives of its family by its elongated, narrow and slightly flattened snout, the length of which is more than half the length of the entire head. The back is distinguished by a black-brown tint, while the sides of the fish are much lighter, and the belly is white, like most species. The fish feeds on mysids and various crustaceans, various worms and small species of fish. The main habitat is represented by the waters of the Caspian, Azov and Black seas, although the sturgeon is also found in the Adriatic and Aegean seas. Before the breeding process, fish appear in the rivers flowing into these seas.
Blunt sturgeon
They spawn in fresh water, always above the tide level. In this case, select areas with fast currents and a rocky bottom with a minimum amount of silt or other organic matter. The spawning time at different latitudes is different; spawning generally takes place at a water temperature of 9-12 degrees Celsius, but it is also possible at 6.5-15 degrees. In the southern part of the range (South Carolina, Georgia) these conditions exist already in January, but in the northern part (New Brunswick, Maine) - only in May[6]. In addition, to begin spawning, other conditions must be met: daylight hours of 13.9-14.9 hours, current speed at the bottom of 30-120 centimeters per second [7]. The fry hatch after 13 days. Each of them has a large yolk sac, and they themselves are 7-11 mm long. Newborn fry see poorly and swim poorly, so they tend to hide in some kind of shelter. After 9-12 days they become well-swimming larvae about 15 mm long. Soon they reach a length of 20 mm, look like miniature adults and begin to feed. In this state, the current carries them down into deeper sections of the river. However, until the end of the first year of their life, the fry remain in fresh water. Having reached a length of approximately 45 cm, the fry move to the river mouth, to the border of fresh and salt water.
Adults are found in both fresh and salt water. Sexual maturity is reached at a length of 45-55 cm, but the further north you go, the later in time sexual maturity occurs. In Georgia, males become sexually mature at 2-3 years, in New Brunswick - only at 10-14. Females reach sexual maturity at the age of 6-17 years (again, the further north, the later). The male participates in his first spawning 1-2 years after puberty, the female - at most 5 years after the onset of puberty. With the onset of sexual maturity, growth does not stop; as a result, short-nosed sturgeons grow to 0.9-1.2 meters. The male can participate in reproduction annually or every second year, his maximum lifespan is about 30 years. Females spawn every third or every fifth year, lay 40,000-200,000 eggs per season, and even live up to 67 years. The long intervals between spawning in females are explained by the fact that during these years they eat little and grow little, spending most of their energy on the production of the gonads necessary for spawning. It is assumed, although not yet proven, that in the northern parts of their range, short-nosed sturgeon live longer[8][9][10].
Natural habitats
The habitat is very extensive, while fish prefer to inhabit the temperate zone, but only within the Northern Hemisphere. They are also found in the Far East, in the Azov, Caspian and Black Seas.
Those species of sturgeon that are not freshwater migrate to the upper reaches of rivers during the spawning season. Some species of sturgeon are bred in artificial conditions, but the peculiarities of their habitat in specific geographical areas are taken into account.
What to feed a sturgeon living in captivity in a swimming pool at the dacha
A very important point is feeding. Sturgeons are not picky eaters, but still require a certain combination and balance in food. The higher quality food is given to the fish, the larger and faster they will grow. And health in general depends on the composition of the diet. Therefore you can use:
- Foreign feed for sturgeon;
- Domestic feed for sturgeon;
- Homemade food.
Why is it indicated that it is for this type of fish? It's simple. Sturgeon is a bottom-dwelling fish, and therefore picks up food from the bottom. Accordingly, it should sink in water, but at the same time retain its appearance for at least half an hour, without getting wet or decomposing. Also, different ages and sizes are supposed to have their own type of feed. (You may also be interested in information about what (composition of feed for laying chickens)
The video shows how to properly feed sturgeon at home:
Ready-made feed
Ready-made food is the best option. They have an attractive smell, which is very important, because this type of fish looks for food by smell. It is better to purchase sturgeon food, which will sink without decomposing in the water. The food remains waterproof for at least 30 minutes after immersion. In the process, it swells a little, becomes soft and fish can eat it faster.
It is better to purchase high-calorie food. Moreover, it must have a certain combination of composition and individual elements:
- Fiber – 3%;
- Raw fats – 20-25%;
- Raw protein 45-50%;
- Phosphorus;
- Lysine;
- Other vitamins and macro-, microelements.
But how much feed a laying hen needs per day and what feed is needed is indicated here.
Small food is purchased for the fry, otherwise they simply will not be able to eat normally. For older individuals, they also purchase food of the appropriate size, otherwise they will simply be malnourished. Adults are fed up to 4 times a day, and fry - up to 6 times. At the same time, timing is important so that the feeding process does not become a complete stress for the fish, followed by a refusal to feed.
How to make it yourself at home - food recipes
Making complete food with your own hands is quite difficult. There are several conditions that must be met during the process:
- Make calculations to create a balanced composition, especially paying attention to the protein content in the feed.
- Add inexpensive but high-quality fishmeal;
- Add micro and macroelements, vitamins to the composition;
- Select vegetable fats;
- During production, it is necessary to monitor the quality and purity of raw materials.
Video shows how to make food for sturgeon at home:
The easiest way to prepare food is to use pork feed, minced trash fish, and bran in the process. Such feed will contaminate the RAS, and therefore it is better to use a homemade composition in ponds and reservoirs of natural composition. In this case, sturgeon will develop, grow and reproduce most fully. It is worth noting that homemade fish food slows down the growth of individuals, but at the same time the quality of caviar increases noticeably, and the taste of the meat will be more natural.
What does sturgeon eat in the wild?
This fish is omnivorous, so it feeds on algae, invertebrates and small fish. If the sturgeon does not have enough animal food, then it necessarily adds food items of plant origin.
Larger individuals often attack waterfowl. Before spawning, the fish tries to stock up on nutrients, so it swallows everything that gets in its way. When the spawning process begins, the fish’s appetite may disappear altogether.
About a month after spawning, the fish begins to actively fatten. Once born, the fry begin to feed on small food items of animal origin. As they grow older, juveniles include larger larvae, worms, insects, etc. in their diet.
Reproduction and offspring
Depending on the species, fish begin to reproduce at the age of 5 to 21 years, and the more severe the climatic conditions, the later the reproduction process begins. Females go to spawn on average once every 3 years.
It is important to know! Representatives of sturgeon spawn starting in March and ending in November, with the peak of spawning occurring at the peak of summer.
For spawning, the fish chooses freshwater areas with a rapid current, which provides the eggs with comfortable ripening conditions due to the presence of the required oxygen concentration. Naturally, fish will not reproduce in salty, and especially in stagnant water. What is most interesting is that eggs develop better in cold water than in warm water, especially since at +22 degrees and above the embryos die.
During the spawning process, females lay several million eggs, up to 3 mm in diameter and weighing about 10 mg. They lay eggs by finding suitable places on the river bottom, crevices in stones, boulders, etc. The eggs are quite sticky because they must withstand the pressure of the rapid current. After this, the eggs begin to ripen, for which they will need about a week and a half.
Sturgeon – description, structure, characteristics, photo. What does sturgeon look like?
Sturgeon is a large fish; the body length of large species can reach 6 meters. The maximum weight of a sturgeon is 816 kg (that’s how much the world’s largest white sturgeon weighed). However, on average, commercial fish weigh 12-16 kg.
The sturgeon skeleton consists of cartilaginous tissue, there are no vertebrae, and the notochord is preserved throughout the life of the fish. The body of the sturgeon is spindle-shaped, highly elongated, devoid of scales and covered with five rows of special scutes-bugs - diamond-shaped bony scales. One row runs along the ridge, on average containing from 10 to 19 scutes, a pair of lateral rows is composed of 25-56 elements, and two rows located on the belly usually consist of 7-15 scutes (depending on the species).
Photo by: Cacophony
Each species of sturgeon is characterized by an individual number of bone bugs. Each of these elements does not merge with the neighboring one and is covered with ring-shaped stripes. Also, small star-shaped bone plates and tubercles are randomly scattered throughout the sturgeon’s body.
The pectoral fin of the sturgeon is very hard, and its spine-like front ray is especially thick and pointed. The age of a sturgeon is often determined by the transverse cut of the front ray. The dorsal fin contains from 27 to 51 rays and is noticeably set back to the tail. The rays of the caudal fin extend beyond the end of the tail and bend around it on both sides. The anal fin may contain from 18 to 33 sharp rays. The swim bladder is well developed.
Photo by: Haplochromis
The head of the sturgeon is small, the snout is elongated, cone- or spatulate-shaped, sharp or slightly blunt. At its end there are 4 antennae, usually simple, devoid of fringe (except for the sterlet, which has fringed antennae). The sturgeon's mouth is retractable and has a lower location, which is due to the peculiarity of the fish's feeding on bottom organisms. The lips are quite fleshy, the lower lip of the fish is interrupted, and there are no teeth. In fry, small teeth grow, but then disappear.
The gill openings of sturgeons are the same as those of sharks, and in the process of evolution they are transformed into squirters. 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 sturgeon is predominantly gray. The back can be light gray, grayish-black or light brown, shimmering green or yellow, the fins are usually dark gray. The fish have brownish sides; the belly of the sturgeon is white, gray with blue or grayish-yellow.
Population and species status
The twenty-first century may go down in history as the century during which humanity will admit that our descendants will not see many species of sturgeon, since they are already threatened with complete extinction. Human activity is due to the fact that many species are helpless against the deterioration of the ecological situation, against active fishing, which lasted almost until the end of the 20th century, as well as the actions of poachers, who are not stopped by any prohibitions.
Scientists note the fact that a decrease in the number of sturgeon was characteristic back in the 19th century, but active measures began to be taken only recently. Such measures include: the fight against poaching, fishing bans, raising fry on farms, after which they are released into natural habitats. Today, bans on sturgeon fishing in general are widespread.
Commercial value
Sturgeon are valued due to the fact that they have tasty and healthy meat and caviar, if they are prepared correctly and professionally. Fish meat is easily digestible by the human digestive tract, and it is rich in proteins (up to 15 percent), vitamins and various minerals, including potassium and Omega fatty acids. Sturgeon has always, for many centuries, been present on the tables of kings, boyars, nobles of many countries and even from the times of Ancient Rome. Alexander the Great carried out long campaigns with his army, and sturgeon caviar was among the provisions.
Sturgeon are suitable for preparing various dishes, so since ancient times their meat has been used to make fish soup, soups, hodgepodge, and also sturgeons have been fried, boiled, stuffed, etc. Sturgeon meat is considered dietary, therefore it is included in recipes for weight loss. The advantage of this fish is that all parts of its body, including the skeleton, are suitable for eating various dishes.
Important point! History shows that sturgeon fat and caviar were used in the production of cosmetics, and glue used in medicine was made from the swim bladder.
Human consumption of dishes prepared from sturgeon has a lot of beneficial effects. It should also be noted that sturgeon fat is only healthy, helping the human body cope with a number of ailments. The caviar of these fish is no less valuable. The list shows value in descending order:
- The most valuable beluga caviar, which is distinguished by its relatively large size and black or grayish color.
- For Russian sturgeon, caviar is in second place in value. Eggs can have different shades.
- In third place in value is stellate sturgeon caviar, which is not large in size.
