Cage culture of longsnout catfish succeeds in Tongling, Anhui
Tongling, Anhui: cage culture of longsnout catfish succeeds
People's Daily Online Anhui Window news: On October 23, employees of the Maozhou Special Aquaculture Company in Tongling County, Anhui Province, and relevant experts observed the growth of longsnout catfish at the cage culture base in the Jiajiang section of the Yangtze River in Tongling.
In the second half of last year, the company cultured longsnout catfish and other precious fish species in cages in Jiajiang, Xuba Township, Tongling County. At present, each longsnout catfish weighs more than 1.7 kg. According to Jiang He, researcher and deputy director of the Fisheries Research Institute of the Anhui Academy of Agricultural Sciences, "The success of cage culture of longsnout catfish in Tongling provides valuable data for demonstrating and promoting longsnout catfish across the province."
[Longsnout catfish profile]
Longsnout catfish (Leiocassis longirostris) belongs to the order Siluriformes, family Bagridae, genus Leiocassis.
Common names: Hui yu, jiangtuan, feituo, feiwang yu, huijiangtuan yu.
English name: Longsnout catfish.
Distribution area: shallow waters north of 40°N, including France in Western Europe, eastern England, western Norway, Siberia in the Soviet Union, Alaska in the United States and Canada. In China, it is distributed in the Heilongjiang River system and the Irtysh River in **.
Body elongated, snout conical and markedly protruding forward. Mouth inferior, crescent-shaped, lips thick and fleshy, eyes small. Four pairs of barbels, small and slender. Scaleless, the posterior margins of the spines of the dorsal and pectoral fins serrated, adipose fin thick and fleshy, caudal fin deeply forked. Body color pink, back slightly gray, belly white, fins gray-black.
It generally lives on the bottom of rivers and also moves in the middle and lower layers of the water body when foraging; in winter it mostly overwinters in crevices among gravel in deep water of the main channel. The longsnout catfish is a carnivorous fish, feeding mainly on small fish and aquatic insects. The minimum age at sexual maturity is 3 years, generally 4-5 years. Adult fish begin to mature each year from March to April, then migrate upstream to spawning grounds in turbulent river water with gravel bottoms. The spawning period is from April to June, and they migrate downstream around August. Fecundity ranges from more than 10,000 to 100,000 eggs. Spawning grounds in the Yangtze River are relatively concentrated in the Jingjiang meander in the middle reaches and in sections such as the Tuo River in the upper reaches.
The longsnout catfish is distributed in the Liao River, Huai River, Yangtze River, Min River to Pearl River systems in eastern China and in western Korea, mainly in the Yangtze River system.
The longsnout catfish grows relatively fast and is the largest species among related fish, with the largest individual reaching 15 kg, while common ones are mostly 2-4 kg. It accounts for a relatively large proportion of the catch in the Yangtze River basin, and is significantly more abundant in the middle and lower reaches than in the upper reaches. Hui yu is a large economic fish; its flesh is tender and delicious, rich in fat, and has no small bones. Its protein content is 13.7%, and its fat content is 4.7%, and it is praised as a top-grade freshwater food fish. The most beautiful part of this fish is the belly with its soft edge. Moreover, its swim bladder is especially thick and fleshy, and after drying it becomes the precious fish maw. The "Bijia fish maw" produced in Shishou City, Hubei Province, has long been famous. It has a thick gel layer, pure flavor, and a semi-transparent color. Its processing technique is unique. The shape of the dried product and a beautiful natural pattern embedded in the swim bladder, when viewed against a light source, closely resemble Bijia Mountain standing in Shishou City, hence the name "Bijia fish maw," and there is a saying that "this item exists only in Shishou, and nowhere else in the world." It is truly a delicacy among foods. As early as the beginning of the Ming Dynasty it was presented as a treasure to Zhu Yuanzhang, Emperor Taizu of Ming, and since then it has continuously been listed as a tribute item. The famous Tang Dynasty poet Du Fu, Song Dynasty poet Su Shi and modern poet Bi Ye all wrote poems and articles greatly praising it. However, in recent years the longsnout catfish resources in the Yangtze River have been declining, and production has dropped sharply. In order to protect and develop this precious fish, the Institute of Hydrobiology of the Chinese Academy of Sciences and the Shishou City Special Aquatic Products Research Institute have collaborated to tackle key problems, and in 1987 achieved breakthrough progress in artificial breeding and culture technology. The dorsal fin spine and pectoral fin spine of the catfish have venom glands, making it one of the more venomous freshwater venomous fishes. After being stabbed, severe pain and burning occur immediately, the wound is punctured and torn, bleeding and local swelling occur, and in individual cases fever may be caused; pain at the affected area is accompanied by itching and stops only after half an hour to 1 hour. Stabbing accidents mostly occur during capture, so care must be taken.
Ecological characteristics
The longsnout catfish has a gray-white body color, gray-black fins, a conical snout protruding forward, small eyes, and four pairs of barbels. It is a carnivorous bottom-dwelling fish and likes to feed at night. Its survival temperature is 0°C-38°C, and the optimal growth water temperature is 24°C-28°C. Below 20°C, feeding decreases and growth slows; its tolerance to low oxygen is similar to that of Chinese carp; sexual maturity is reached at 3 years of age, males are larger than females, and spawning occurs from April to June each year. Fry bred in the same year can grow to 100-150 g by the end of the year, and in the following year can be raised to the market size of 500 g, while the body weight of a 3-year-old fish reaches 1 kg.
Culture technology
The pond for stocking should have little silt, a single pond area of 4-6 mu, and a water depth of more than 1.5 m, with clear water quality. Some aquatic plants such as water hyacinth should be stocked in the pond to suit the longsnout catfish's habit of preferring darkness and avoiding light. For main culture, stock 1000 fry of more than 5 cm per mu, and appropriately mix in some silver carp and bighead carp to control water quality. Before stocking, soak the fry in 3% salt water or 5 ppm potassium permanganate solution for 10-15 minutes to disinfect the fish body. Feeding starts mainly with earthworms and eel feed, then gradually trains them to eat other feeds. When they grow to more than 8-10 cm, switch to compound feed containing about 30% protein or peanut bran, soybean cake, etc. The daily feeding amount is 5%-7% of fish body weight in summer and autumn, and 1%-4% of fish body weight in winter and spring. Do a good job in water quality management, generally replacing one third with fresh water every week, keeping the water clear, with a transparency of about 35 cm, pH 7.2-7.5, and dissolved oxygen 3-6 mg/L; apply 10 kg of quicklime per mu each month to regulate water quality and prevent disease. When the longsnout catfish is used as a secondary culture species, it can be polycultured with eel, mandarin fish, largemouth bass, etc., stocking 200 fish per mu, but it should not be polycultured with catfish, tilapia, white pomfret, common carp, crucian carp and other bottom-dwelling fish, to avoid competition for feed.
The longsnout catfish has many culture diseases, among which the more harmful one is ichthyophthiriasis, especially causing mass mortality at the fry and fingerling stage. In the early stage of the disease, bathing the fry with 20-40 ppm formaldehyde has a good effect.
Reproductive habits: usually 300-500 mm, growing fast in the first 4 years, then slowing down in the next 4 years. Long lifespan. The known maximum age is 22 years, sexual maturity is relatively late, and the minimum mature age is 3 years. The spawning period is from December to January of the following year, and the water temperature during spawning is about 2°C. During spawning, they choose sandy or gravelly river shoals 1-3 m under the ice. Burbot inhabiting lakes also migrate to rivers to spawn. During spawning, the male fish first reaches the spawning ground, and the female fish arrives only after 3-4 days. The male fish mostly circles to chase the female fish, and after circling, the male and female fish respectively quiver their bodies to release eggs and sperm. Spawning activity mostly occurs at night. Fecundity varies greatly with fish body size: a fish with a body length of 340 mm has 57,000 eggs, and a fish with a body length of 870 mm has 3 million eggs. The incubation period of the larvae is long, about 60 days, and the newly hatched larvae have a body length of 3.8-4.3 mm. It is a ferocious carnivorous fish and a nocturnal feeder. Juveniles with a body length of 50 mm feed on larvae of planktonic, trichopteran, dipteran and other insects. Adults feed entirely on fish. There is almost no selectivity, and they cannibalize each other when food is scarce.
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I learned something new; I had never heard of this before!
--------------------------------------
This is new to me; it seems I really am ignorant!
In the second half of last year, the company cultured longsnout catfish and other precious fish species in cages in Jiajiang, Xuba Township, Tongling County. At present, each longsnout catfish weighs more than 1.7 kg. According to Jiang He, researcher and deputy director of the Fisheries Research Institute of the Anhui Academy of Agricultural Sciences, "The success of cage culture of longsnout catfish in Tongling provides valuable data for demonstrating and promoting longsnout catfish across the province."
[Longsnout catfish profile]
Longsnout catfish (Leiocassis longirostris) belongs to the order Siluriformes, family Bagridae, genus Leiocassis.
Common names: Hui yu, jiangtuan, feituo, feiwang yu, huijiangtuan yu.
English name: Longsnout catfish.
Distribution area: shallow waters north of 40°N, including France in Western Europe, eastern England, western Norway, Siberia in the Soviet Union, Alaska in the United States and Canada. In China, it is distributed in the Heilongjiang River system and the Irtysh River in **.
Body elongated, snout conical and markedly protruding forward. Mouth inferior, crescent-shaped, lips thick and fleshy, eyes small. Four pairs of barbels, small and slender. Scaleless, the posterior margins of the spines of the dorsal and pectoral fins serrated, adipose fin thick and fleshy, caudal fin deeply forked. Body color pink, back slightly gray, belly white, fins gray-black.
It generally lives on the bottom of rivers and also moves in the middle and lower layers of the water body when foraging; in winter it mostly overwinters in crevices among gravel in deep water of the main channel. The longsnout catfish is a carnivorous fish, feeding mainly on small fish and aquatic insects. The minimum age at sexual maturity is 3 years, generally 4-5 years. Adult fish begin to mature each year from March to April, then migrate upstream to spawning grounds in turbulent river water with gravel bottoms. The spawning period is from April to June, and they migrate downstream around August. Fecundity ranges from more than 10,000 to 100,000 eggs. Spawning grounds in the Yangtze River are relatively concentrated in the Jingjiang meander in the middle reaches and in sections such as the Tuo River in the upper reaches.
The longsnout catfish is distributed in the Liao River, Huai River, Yangtze River, Min River to Pearl River systems in eastern China and in western Korea, mainly in the Yangtze River system.
The longsnout catfish grows relatively fast and is the largest species among related fish, with the largest individual reaching 15 kg, while common ones are mostly 2-4 kg. It accounts for a relatively large proportion of the catch in the Yangtze River basin, and is significantly more abundant in the middle and lower reaches than in the upper reaches. Hui yu is a large economic fish; its flesh is tender and delicious, rich in fat, and has no small bones. Its protein content is 13.7%, and its fat content is 4.7%, and it is praised as a top-grade freshwater food fish. The most beautiful part of this fish is the belly with its soft edge. Moreover, its swim bladder is especially thick and fleshy, and after drying it becomes the precious fish maw. The "Bijia fish maw" produced in Shishou City, Hubei Province, has long been famous. It has a thick gel layer, pure flavor, and a semi-transparent color. Its processing technique is unique. The shape of the dried product and a beautiful natural pattern embedded in the swim bladder, when viewed against a light source, closely resemble Bijia Mountain standing in Shishou City, hence the name "Bijia fish maw," and there is a saying that "this item exists only in Shishou, and nowhere else in the world." It is truly a delicacy among foods. As early as the beginning of the Ming Dynasty it was presented as a treasure to Zhu Yuanzhang, Emperor Taizu of Ming, and since then it has continuously been listed as a tribute item. The famous Tang Dynasty poet Du Fu, Song Dynasty poet Su Shi and modern poet Bi Ye all wrote poems and articles greatly praising it. However, in recent years the longsnout catfish resources in the Yangtze River have been declining, and production has dropped sharply. In order to protect and develop this precious fish, the Institute of Hydrobiology of the Chinese Academy of Sciences and the Shishou City Special Aquatic Products Research Institute have collaborated to tackle key problems, and in 1987 achieved breakthrough progress in artificial breeding and culture technology. The dorsal fin spine and pectoral fin spine of the catfish have venom glands, making it one of the more venomous freshwater venomous fishes. After being stabbed, severe pain and burning occur immediately, the wound is punctured and torn, bleeding and local swelling occur, and in individual cases fever may be caused; pain at the affected area is accompanied by itching and stops only after half an hour to 1 hour. Stabbing accidents mostly occur during capture, so care must be taken.
Ecological characteristics
The longsnout catfish has a gray-white body color, gray-black fins, a conical snout protruding forward, small eyes, and four pairs of barbels. It is a carnivorous bottom-dwelling fish and likes to feed at night. Its survival temperature is 0°C-38°C, and the optimal growth water temperature is 24°C-28°C. Below 20°C, feeding decreases and growth slows; its tolerance to low oxygen is similar to that of Chinese carp; sexual maturity is reached at 3 years of age, males are larger than females, and spawning occurs from April to June each year. Fry bred in the same year can grow to 100-150 g by the end of the year, and in the following year can be raised to the market size of 500 g, while the body weight of a 3-year-old fish reaches 1 kg.
Culture technology
The pond for stocking should have little silt, a single pond area of 4-6 mu, and a water depth of more than 1.5 m, with clear water quality. Some aquatic plants such as water hyacinth should be stocked in the pond to suit the longsnout catfish's habit of preferring darkness and avoiding light. For main culture, stock 1000 fry of more than 5 cm per mu, and appropriately mix in some silver carp and bighead carp to control water quality. Before stocking, soak the fry in 3% salt water or 5 ppm potassium permanganate solution for 10-15 minutes to disinfect the fish body. Feeding starts mainly with earthworms and eel feed, then gradually trains them to eat other feeds. When they grow to more than 8-10 cm, switch to compound feed containing about 30% protein or peanut bran, soybean cake, etc. The daily feeding amount is 5%-7% of fish body weight in summer and autumn, and 1%-4% of fish body weight in winter and spring. Do a good job in water quality management, generally replacing one third with fresh water every week, keeping the water clear, with a transparency of about 35 cm, pH 7.2-7.5, and dissolved oxygen 3-6 mg/L; apply 10 kg of quicklime per mu each month to regulate water quality and prevent disease. When the longsnout catfish is used as a secondary culture species, it can be polycultured with eel, mandarin fish, largemouth bass, etc., stocking 200 fish per mu, but it should not be polycultured with catfish, tilapia, white pomfret, common carp, crucian carp and other bottom-dwelling fish, to avoid competition for feed.
The longsnout catfish has many culture diseases, among which the more harmful one is ichthyophthiriasis, especially causing mass mortality at the fry and fingerling stage. In the early stage of the disease, bathing the fry with 20-40 ppm formaldehyde has a good effect.
Reproductive habits: usually 300-500 mm, growing fast in the first 4 years, then slowing down in the next 4 years. Long lifespan. The known maximum age is 22 years, sexual maturity is relatively late, and the minimum mature age is 3 years. The spawning period is from December to January of the following year, and the water temperature during spawning is about 2°C. During spawning, they choose sandy or gravelly river shoals 1-3 m under the ice. Burbot inhabiting lakes also migrate to rivers to spawn. During spawning, the male fish first reaches the spawning ground, and the female fish arrives only after 3-4 days. The male fish mostly circles to chase the female fish, and after circling, the male and female fish respectively quiver their bodies to release eggs and sperm. Spawning activity mostly occurs at night. Fecundity varies greatly with fish body size: a fish with a body length of 340 mm has 57,000 eggs, and a fish with a body length of 870 mm has 3 million eggs. The incubation period of the larvae is long, about 60 days, and the newly hatched larvae have a body length of 3.8-4.3 mm. It is a ferocious carnivorous fish and a nocturnal feeder. Juveniles with a body length of 50 mm feed on larvae of planktonic, trichopteran, dipteran and other insects. Adults feed entirely on fish. There is almost no selectivity, and they cannibalize each other when food is scarce.
--------------------------------------
I learned something new; I had never heard of this before!
--------------------------------------
This is new to me; it seems I really am ignorant!