What kind of fish is this? Is it a catfish?

Sturgeon name: Sturgeon

Latin name: Acipenser sturio Linnaeus

English name: Common sturgeon

Classification: Fish, Actinopterygians, order Acipenidae, family Acipensidae, genus Acipenser.

Body length: ranging from 0.5 to 7 meters

Weight:

Common individuals of most species range from tens to hundreds of kilograms, and the European catfish is the largest. An individual weighs 1,600 kilograms, and the largest Chinese sturgeon weighs 600 kilograms.

Form:

Sturgeon is the largest, longest-lived and oldest fish in the world.

The sturgeon is an existing ancient biological population that originated in the Cretaceous period hundreds of millions of years ago. It is known as the "panda" in the water. Sturgeons are kept as ornamental fish due to their unusual shape. The sturgeon has a plow-shaped head, a lower mouth, a crooked tail, and 5 rows of bony plates on the back of the body. Both its juveniles and adult fish have ornamental value. Among them, Acipenser schrenckii (distributed in Heilongjiang) has been artificially bred as an ornamental fish since its artificial breeding was successful.

Geographical population differences:

There are currently 26 species of sturgeons on the earth: 7 species distributed in North America, 12 species in Europe, and 11 species in Asia (8 species in my country).

Distribution:

Sturgeons are concentrated in the northern hemisphere. There are 8 species of sturgeons living in rivers and coastal areas of my country, 3 of which are distributed in Xinjiang, 2 in Heilongjiang, and 2 in Heilongjiang. In the Yangtze River, 1 species is found in rivers from the Yangtze River to the Pearl River and along the coast.

Species status:

A few species are critically endangered species

Living habits:

Sturgeons feed on benthic invertebrates and small Fish for food.

Living environment:

Sturgeons have strict requirements on water quality and like to live in flowing water, high dissolved oxygen content, low water temperature and gravel bottom.

Value

Economic value

The economic value of sturgeon is very high. In 1998, the international price of sturgeon meat was 60 US dollars/kg and roe 300 US dollars. US$/kg, caviar is as high as US$700/kg. Sturgeon skin is a good raw material for making high-end leather products. Its tear resistance, durability and flexibility are comparable to crocodile skin.

There are 27 species of sturgeons in the world, 8 species in my country. Chinese sturgeon, Acipenser schrenckii and Acipenser daschia are the three main species of sturgeon in my country. Among them, the important species of sturgeon is Chinese sturgeon. Rare aquatic animals not only have important scientific research value and special academic significance, but also have high economic value and medicinal value. They are listed as first-class protected animals by the country and are aquatic products loved by people at home and abroad in ancient and modern times.

Comprehensive utilization

Sturgeon is a famous and high-quality treasure in my country. It has delicious meat, soft bones and high nutritional value. The protein content of sturgeon meat and eggs can be as high as 18% and 29%. %. Calculated based on the 25% seeding rate of female sturgeons, the fish body still accounts for more than 75%, and the processing potential is huge. Sturgeon meat is processed into small packaged smoked products, grilled fish fillets, fried fish floss, sauced fish liver, and smoked grilled fish sausages. etc. are very popular among merchants in the international market. According to market research, Western Europe and Americans are more interested in smoked and grilled sturgeon products, and the prices are considerable. Domestic hotels and restaurants have always been in the habit of using smoked and grilled sturgeon products to entertain customers.

The sturgeon is full of treasures and is highly utilized. In addition to the sturgeon meat, its maw, nose, tendons, and bones can be used to make unique Chinese dishes. Excellent delicacies, with endless aftertaste after the meal, often appear on the tables of state banquets; fish skin can be used to make glue and is also a raw material for high-grade leather; fish bones are used as raw materials for high-calcium delicious food, which has unique medicinal value and is good for It is very beneficial to prevent osteoporosis in the elderly, enhance body immunity, improve brain vitality and promote human health.

The precious sturgeon caviar sauce is particularly worth mentioning, which is known as "black gold". It is processed from sturgeon eggs and is a high-end food well-known at home and abroad. The international market is very popular. In 1997, the market price of sturgeon was US$64/kg, sturgeon roe was US$300/kg, and sturgeon roe paste was as high as US$500-700/kg, and it was still rising, with demand exceeding supply. The nutritional value of sturgeon roe is basically the same. They are both dark brown transparent round granules containing high protein, trace elements and multiple vitamins. Salt-treated sturgeon roe paste is collectively called black caviar paste and is the leader in the industrialization of sturgeon processing. The product is known as "black gold" because of its high price. The raw fish used for caviar processing must be alive, and the male to female ratio is generally 1:1. Since the eggs of various sturgeons vary in size, they must be further graded and processed. The general processing procedures of black caviar are: live fish → bleeding → egg mass removal → egg separation → washing and water control → pickling → draining and canning → refrigeration. The main components of the finished product are as follows: protein 26% to 29%, fat 13% to 17%, moisture about 50%, ash 0.5% to 1.0%, and salt 3% to 4%.

It also contains a variety of amino acids, among which the main essential amino acid contents are: threonine 3.15%, valine 3.09%, methionine 0.98%, leucine 4.91%, isoleucine 2 .83%, phenylalanine 2.13%, lysine 4.81%. It can be seen that the content of lysine is relatively high, and the proportion of essential amino acids is also close to the amino acid composition of the human body. It is raw food, so the nutritional value higher.

Ornamental value

Sturgeon is a cartilaginous fish with scales. It is an ancient fish and is known as a living fossil. It has a unique shape, with a cone-shaped body and a flat head and trunk. Wearing five-element bone plates with sharp spines like armor, it swims as quietly as a shuttle. Its body is black and gray, its belly is white, and its tail is crooked. It has a deep, simple and unique feeling. It has high ornamental value. It is popular in Southeast Asia and Hong Kong, Macao, Taiwan and other regions regard it as a top-quality ornamental fish. In recent decades, due to human factors such as environmental pollution and overfishing, the sturgeon ecosystem has been severely damaged, causing some species of sturgeon to be on the verge of extinction. In order to save these endangered species, countries around the world have done a lot of fruitful research work on sturgeon breeding, release, and culture. With the success of sturgeon breeding, it has not only added richer new varieties to our country, but also set off a new craze for sturgeon breeding in our country. It has also met market demand, especially in terms of export earnings, and achieved greater economic benefits.

Sturgeon also has certain ornamental value. Its body is like a shark, and it can swim flat, backward, sideways and vertically in the water. It is as spectacular as a submarine. It also has high research value. Dinosaurs originated in the Cretaceous period hundreds of millions of years ago and are probably extinct. However, sturgeons can survive tenaciously and are "living fossils" used by countries around the world to study crustal changes. ".

Food value

Sturgeon is a large economic fish with excellent food value. Except for the bone plates on the body, all other parts of the body (including bones) are edible. It has extremely high nutritional value and is classified as a high-grade tonic.

Sturgeon has long been a favorite food of ancient people. For example, Lu Ji's "The Book of Songs. Wei Feng. Shuo Ren" states: "(Sturgeon is a sturgeon) weighing more than a thousand kilograms. It can be steamed into sturgeon, fried, and the roe can be made into sauce." "Compendium of Materia Medica. Sturgeon" It says: "The layers of fat and meat alternate with each other. The flesh is white in color and the fat is as yellow as wax." Its spine and nose, as well as its fins and gills, are all brittle and edible. Its belly and larvae are also good for storing salt. Its swim bladder can also be used as glue. Its meat and bones are delicious both grilled and fried. "Today's internationally renowned caviar is a state banquet treasure in Europe and the United States, known as "emerald". Smoked sturgeon meat, fresh meat, isinglass, etc. are popular and the supply exceeds demand. In ancient my country, it has long been famous all over the country.

Sturgeon has been used for medicinal purposes in ancient times. "Compendium of Materia Medica. Anchovy" quotes Chen Chen Zangqi as saying: "The liver is mainly used to treat malignant sores and scabies. Do not eat them with salt." The quote under the article "Fish" says: "The meat can nourish Qi, strengthen the body, boil the juice and drink it to treat bloody stranguria; the meat of the nose can be used as preserved meat to nourish Qi; its seeds are like adzuki beans, which can be eaten to strengthen the body and kill small insects in the abdomen. . "According to the Institute of Oceanography, Chinese Academy of Sciences: Muscle contains more than ten kinds of essential amino acids for the human body, and fat contains 12.5% ??"DHA" and "EPA" (also known as brain gold), which can soften cardiovascular and cerebrovascular vessels, promote brain development, and improve IQ. It has a good effect in preventing Alzheimer's disease; cartilage and bone marrow (commonly known as "dragon tendons") have anti-cancer factors and can be eaten directly. They are known as "shark fins and sturgeon bones"

Nutrition. Requirements

Sturgeon is an animal-feeding fish and can prey on zooplankton during its feeding stage. However, the fry soon develop into a benthic life and are adapted to this lifestyle. The sturgeon's mouth is protruding and lower. The food that sturgeons like varies with different species. The main foods are earthworms, crustaceans, molluscs, and small fish. The sturgeon fry can be fed artificially directly after eating. For feed, in actual production, sturgeon fry that have just opened their mouths are often fed with live bait (zooplankton or chopped earthworms). After about 30 days of feeding, the sturgeon fry can grow to a body length of 3.8-9.4cm and a body weight of 3.8-9.4cm. With a size of 0.5-3.9g, the survival rate can reach more than 60%. However, due to the difficulty in obtaining live bait and its high price, people have successfully tamed artificial compound feed after sturgeon fry are cultivated with live bait for about 30 days. Use compound feed to grow sturgeon into commercial fish and put it on the market.

List of existing sturgeon species in the world

(The first is the English name, the latter is the Latin name)

Siberian sturgeon Acipenser baeri Brandt

Shortnose sturgeon Acipenser brevirostrum Lesueur

River sturgeon Acipenser dabryanus Dumeril

Lake sturgeon Acipenser fulvescens Rafinesque

Russian sturgeon Russian sturgeon Acipenser gueldenstaedti Brandt

Green sturgeon Acipenser medirostris Ayres

Ship sturgeon Acipenser nudiventris Lovetzky

Atlantic sturgeon Acipenser oxyrhynchus Mitchill

Sterlet Acipenser ruthenus Linnaeus

Amur sturgeon Acipenser schrenckii Brandt

Chinese sturgeon Acipenser sinensis Gray

Stellate sturgeon Acipenser stellatus Pallas

Common sturgeon Acipenser sturio Linnaeus

White sturgeon Acipenser transmontanus Richardson

Paddlefish Polyodon spathula

Chinese paddlefish Psephurus gladius

Asiatic shovelnose sturgeon Pseudoscaphirhynchus fedtschenkoi

Pygmy sturgeon Pseudoscaphirhynchus hermanni

Silk-tailed sturgeon Threadtail sturgeon Pseudoscaphirhynchus kaufmanni

Pallid sturgeon Scaphirhynchus albus

Shovelnose sturgeon Scaphirhynchus platorhynchus

Captive rearing

Sturgeon Although the artificial breeding of fish has a history of hundreds of years, it is still an emerging industry in our country. Since all parts of the sturgeon's body are edible and taste delicious and unique, sturgeon farming can achieve high benefits.

Cage culture

Cage culture uses the good ecological environment of large water bodies and combines the characteristics of small water bodies in cages for intensive breeding. Generally, water areas such as valley-shaped reservoirs are selected, which require fresh and pollution-free water quality and an average water depth of 12 meters.

1. The cage setting specifications are 5 meters × 5 meters and 4 meters × 4 meters. The net clothing is of polyethylene structure. The size of the mesh depends on the specifications of the sturgeon species. In order to prevent fish from escaping and have In order to facilitate the exchange of water bodies and ensure that the bottom mesh does not leak bait, the cage should be set up in a place with good water quality and a water depth of more than 8 meters. It should also have conditions such as micro current, wind protection, sunshine and wide water surface. For large reservoirs, appropriate reservoir bays should be selected to set up cages, while for small reservoirs, cages should be set up not far from the reservoir dam.

2. Seed stocking. Set up the net cage in mid-April. The net clothing will no longer feel rough after being soaked in the reservoir water, so as to reduce the fish species entering the box from swimming in fear due to changes in the environment, and thus being trapped in the net. Chances of clothing abrasions. The appropriate stocking time is mid-to-late April, and the water temperature is around 10-15°C, which is the optimal growth temperature for sturgeon. The bigger the stocking size, the better, usually 75-150 grams per tail, and the stocking density is 40-50 tails/square meter. Before putting the fish into the box, disinfect them with 3%-4% salt water. The temperature difference between the transport water and the reservoir water should not exceed 5℃.

3. Feed can be fed with artificially mixed pellets, which require a protein content of 42%-45%. The main raw materials include fish meal, yeast, blood meal, wheat, corn, silkworm pupae, etc. The stability of the pellets in water is Keep it high for more than half an hour. After the fish enter the box, feeding should be stopped for 2-3 days to allow the fish to adapt to the environment. Feeding should be started after 2-3 days. Feeding should be done in small amounts and multiple times at the beginning to attract food. The particle size of the bait should be adjusted in time as the fish body increases to achieve a palatable size. Feed once a day in the morning, middle and evening. Sturgeons have the habit of foraging at night. Feed once at night. The daily feed amount is 2%-4% of the fish body weight in the box. At the same time, the amount of feed should be based on the weather, water temperature, and the fish's food intake. It depends.

4. For daily management, special personnel should be arranged to monitor and inspect the containers in the morning, noon and evening. One hour after each feeding, the fish should be picked up to check the eating status and the amount of feeding should be adjusted. If there are dead fish floating in the box, the box should be picked up to check and any sick or dead fish in the box should be fished out. The cage should be cleaned every 10 days or so to remove debris on the net and excessive algae attached to it, keep the water exchange inside and outside the cage smooth, and adjust the density in a timely manner as the fish grows. The cages are replaced once a month. The nesting method is used when replacing them. That is, the cage to be replaced is soaked for 2-3 days and then placed in the cage containing sturgeon to be replaced. outside and secure it, and then carefully untie the cage to be replaced and pull it out of the water. Rinse and repair the replaced cages in preparation for replacement. Note that if it enters the high temperature season, try to avoid dumping fish to avoid losses.

5. Fish Disease Prevention and Control: Soak the cages with quicklime or bleaching powder before launching them into the water, 7-10 days in advance. Soak the fish species in 3%-4% salt water for 10-15 minutes before entering the cages. Every 15-20 days, use 2-3 kilograms of quicklime per box, and sprinkle the box and nearby waters with dissolved water, once a day for 3 consecutive days. At the same time, use bleaching powder and trichlorfon hanging bags at the four corners of the cage ( Master the concentration of bleaching powder hanging bag). During disinfection, lift the four corners of the cage to reduce the water volume, increase the drug concentration, and observe the stress response. When stress occurs, lower the four corners.

Pond culture

Sturgeon is a large fish with fast growth speed, strong disease resistance and adaptability. The following issues should be paid attention to in pond culture.

1. Pond conditions Sturgeon breeding ponds require a large area, deep pool water, sufficient water sources, fresh water quality and pollution-free areas, convenient transportation and complete communication facilities. The appropriate pond area is 5-10 acres, the water depth is 2-3 meters, the water quality is relatively stable, and the dissolved oxygen value of the water body is high, preferably above 5 mg/L. The pond should have independent inlets and drainage outlets, slopes, a waterwheel-type aerator, and a feed table.

2. Clear the pond and disinfect it half a month before releasing seedlings. 15-20 cm of water will enter the pond, mix it with 100-150 kg/mu of quicklime and then sprinkle it over the whole pond to eliminate harmful organisms in the water; soak the pond for 3 days -After 4 days, drain the pond water out of the pond, and then soak the bottom of the pond with water. Filter the water inlet with a 60-mesh sieve; use 15-20 kg/acre of tea cake to clear the pond and disinfect it. Before disinfection, break the tea cake into pieces and After soaking in water for 1 day, splashing the whole pond can kill fish, shrimp and fish and shrimp eggs in the pond. After clearing the pond, the tea bran will be left in the pond to be used as fertilizer. Ten days before planting seedlings, add water to the pond to a depth of 70-80 cm, and then disinfect it with chlorine-containing disinfectant.

3. 7-8 days before cultivating plankton and releasing seedlings, prepare 50 kilograms of dry chicken manure per acre of pond and soak the chicken manure for 2 days. It is best to disinfect with chlorine-containing disinfectant and then remove impurities. After the substance (filtered), the whole pool is splashed. After the filter is wrapped with a fiber bag, it is placed in the downdraft of the pond and continues to be used as fertilizer for cultivating plankton.

4. For seed stocking, it is better to choose healthy and disease-free sturgeon seed with a body length of more than 20 cm. Generally, the stocking density of large-sized seedlings is 400-600/acre. The time for releasing seedlings should take into account not only the appropriate water temperature, but also the availability of adult fish.

Feeding should be stopped 1-2 days before seed transportation. Use 38×82 polyethylene packaging bags for transportation, add 3/5 of water to the bag, and use ice cubes to adjust the water temperature to 12-15 ℃, put 20 fry with a body length of 20-30 cm into each bag, and pack them for transportation. If the transportation time is within 8 hours, it can be transported by water truck, but you must always pay attention to the changes in water temperature during transportation, and the effect is also very good.

Test the water two days before releasing the fry. Put about 10 fry of the same specifications into the cage and observe the sturgeon's activities. If there are no abnormalities, release the fry. When releasing seedlings normally, do not untie the delivered seedling bags first. Put the whole bag into the pond. Slowly make the water temperature in the bag close to the pond water temperature, then open the bag and put the seedlings into the pond. For farms that have the conditions, it is best to pour the fish and water into a large bucket to keep it continuously inflated, then put salt in the bucket to make the salinity reach 2%, soak the fish body for 10 minutes and then put the fry into the pool.

5. Feeding Pond aquaculture is mainly based on feeding compound feeds. When the sturgeon fry first enter the pond, they have not yet formed the habit of eating in a fixed place, so they must be acclimated in time.

Feed can be placed on the feed table to improve feed utilization and facilitate daily observation. Some sturgeons, such as Acipenser schrenckii, hybrid Acipenser, Russian Acipenser, Chinese Acipenser, etc., have the characteristic of phototropism at night. When acclimating at night, they can be illuminated near the feeding table.

Feeding should adhere to the principle of small amounts and frequent meals. The feed should be palatable and the particle size should not be too large or too small. Generally, 1/2 of the fish's mouth cleft is suitable.

The feeding amount is about 3% of the fish body weight, feeding 3-4 times a day, and the feeding amount can be adjusted at any time depending on the specific situation.

6. Daily management of pond patrols and observation of growth conditions. Patrol the pond once a day in the morning, noon and evening, especially at night and in the early morning. Pay attention to the activities of the fish to prevent hypoxia; when the air pressure is low in the rainy season in summer, patrol the pond frequently and take timely measures if any problems are found. Turn on the aerator or add new water and other measures to prevent pond flooding. Regularly check the growth and health of sturgeons, and adjust the feeding rate and stocking density in a timely manner. When the growth difference of sturgeons in the pond is too large, the ponds must be divided into ponds in time according to their specifications. In water quality management, water temperature is measured three times a day, and physical and chemical factors such as pH, dissolved oxygen, nitrite, and ammonia nitrogen are measured regularly. It is worth noting that sturgeons are typical bottom-dwelling fish and generally do not float. Some species, such as the Chinese sturgeon, do not float as obviously as domestic fish even when the dissolved oxygen in the water is insufficient, so under special circumstances , if the water temperature is too high, the water color is wrong, or the weather is muggy, it is necessary to strengthen the monitoring of water quality and measure the dissolved oxygen in the water every morning. When the color of the pond water is too thick, the water transparency is lower than 25 cm or the dissolved oxygen is less than 5 mg/L, new water must be added to the pond to keep the water quality fresh. The most suitable pH value for sturgeon growth is 6.5-8.0. A pH value that is too low will affect the metabolic activity and growth of sturgeon, and even endanger life. The upper temperature limit for most sturgeons to survive is 32°C. Water temperatures exceeding 30°C are dangerous to the growth of sturgeons. Water temperature control can refer to the following measures: choose a suitable stocking time and release large-size fish species to shorten the breeding cycle; strive to release large-size fish species after the high-temperature period each year, and reach the grow-out size before the arrival of the high-temperature period in the following year. Avoid high temperatures; when the high temperature period arrives, deepen the water level and reduce the stocking density; where conditions permit, measures such as increasing the amount of water changes and setting up sheds for shading can also be taken.

7. Disease prevention and treatment Symptoms of fungal diseases are slow movement, weight loss, and no food intake. The prevention and treatment method is to prevent fish injuries. For sick fish, you can use clotrimazole and a mixed solution of 1% salt and baking soda to soak the affected fish for about 10 minutes. Bacterial diseases are highly contagious and often harm fish species with high mortality rates. The prevention and treatment method is to first carry out environmental disinfection, and at the same time add multivitamins and immune polysaccharides to the feed to improve the immunity of the fish; you can also add appropriate amounts of non-residue antibiotics and Chinese herbal medicine to the feed for prevention. The symptoms of leukoplakia are the lack of mucus on the body surface and the body color of the fish turning white, which can be treated with antibiotics. Symptoms of bacterial enteritis include abdominal and oral bleeding, anal redness and swelling, and fish weight loss. Norfloxacin and other drugs can be used to disinfect the fish, and Chinese herbal medicine can be added to the feed for treatment. Parasitic fish diseases mainly include third-generation worms, trichozoa, melon worms, etc. The prevention and control methods can be to soak the fish in 5% salt solution for 1 hour, or soak the fish in 20% formalin solution; you can also use Treatment with Chinese herbal medicine. Non-pathogenic diseases mainly include hepatic encephalopathy, epicardial abscess, black body disease, potbelly disease, etc. The main causes of these diseases are poor breeding environment, unreasonable feed ingredients, etc. Pay attention to improving the environment and strengthening feed quality management. .

Sturgeon

("Compendium of Materia Medica")

Synonyms: tuna ("The Book of Songs"), 饥 ("The Biography of Mao's Poems"), 鲛鲔 ( "Erya"), Weiyu, Zhongmingyu (Lu Ji's "Poetry"), Wei (annotation of "Erya" by Guo Pu), Qili Mayu ("Yinshan Zhengyao"), Biyu ("Compendium") 》).

The source is the meat of the Chinese sturgeon, a sturgeon in the family Acipensidae.

Animal form: Chinese sturgeon

The body is more than 2 meters long, with a narrow back and a straight ventral surface. The snout is nearly plow-shaped, slightly upward, and the head is covered with smooth bony plates. The mouth and abdomen form a transverse cleft, with 2 pairs of rostrum barbels, equal in length and arranged in parallel rows. Small eyes. The gill openings are large, and the gill rakers are thin and pointed, about 22 in number. There is one bony plate on each side of the jaw; there are 5 rows of bony plates on the body, one row in the middle of the back is larger, and there are 2 rows on the dorsal and ventral sides. There are also 1 to 2 bony plates on the front and rear of the anal fin: there are spinous bones on the upper lobe of the caudal fin. The board has one row, and the other parts are smooth and scale-free. The dorsal fin is 54-66; the pectoral fin is well-developed and is inserted on the ventral surface; the anal fin is 32-41; the caudal fin is crooked and the upper lobe is well-developed. The back and head are blue-grey, the belly is white, and the fins are all blue-gray.

Live in rivers and offshore waters. Distributed in Changgan, Qiantang River Basin and other coastal areas.

In addition, there are white sturgeons of the family Acipensidae that are more than 2 meters long. Bare and smooth, with only small scales. The back is gray-green and the belly is white. The head is long, the snout is extended and protrudes like a sword, the mouth and abdomen are located, and the eyes are small. Distributed in the East China Sea and Yellow Sea, entering Qiantang River, Yangtze River, Yellow River, etc. This is the sturgeon mentioned in the "Compendium".

The swim bladders (fish bladders) of the above animals are also used for medicinal purposes. Please refer to this article for details.

Its nature and flavor are sweet and flat.

① "Supplementary Materials of Materia Medica": "Sweet, flat, non-toxic."

② "Yilin Compilation Essentials": "Sweet, warm."

Meridian tropism "Compendium of Materia Medica": "Start with Taiyin, Jueyin meridian."

Functions: Replenishing qi and replenishing deficiency, promoting blood circulation and relieving stranguria.

① "Dietotherapeutic Materia Medica": "It is mainly used for bloody stranguria. It can be boiled and drunk."

② "Supplementary Materials of Materia Medica": "Replenishing qi and replenishing deficiency, making people fat and healthy."< /p>

③ "Essentials of Drinking and Diet": "Benefits the Five Tibetans and makes people fat."

④ "Suixiju Diet Manual": "Nourishes the stomach, activates blood circulation and relieves stranguria."

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Usage and dosage. Oral administration: Cook.