The stocking of fish species looks very simple, but if improper measures are taken in all aspects of specific operations, it will result in varying degrees of loss. According to the author's experience, the following issues should be paid attention before the stocking work.
1, according to the conditions of the waters and sources of feed to determine the species of stocking species, specifications and quantity.
If the fish farming waters are standard fish ponds or small ponds within 3.3 hectares (50 acres), as long as there are water sources, the water quality is good, and the amount of bait suitable for feeding various fishes is sufficient, then the main fishes and the collocations are the main fishes. The principle of collocation and polyculture is to select fish of different food habits and different activities in the water layer, and also to consider the specific conditions of the pond. If the fish farming waters are large water surfaces, such as lakes, reservoirs, etc., based on experience, it is better to store fish species such as white peony, grass carp, head bream, and carp. In order to use white fleas as the dominant species, stocking species should have large specifications, generally about 20 per kilogram. The number of fish species to be placed in various waters shall be weighed and determined by a combination of factors such as the amount of plankton, benthos, aquatic grasses and other natural baits, and the funds and management levels of the purchased baits. It can also be determined according to the quantity, specifications, and specifications at the time of raising water in the waters that have been raised in recent years. If the size of the fish when the water is raised is large and much larger than the product size, the number of stocking in the second year can be more, and vice versa. The number of stocking can be reduced. At present, many farmers do not ask for quality only because of their quantity. When the water is raised, the specifications of the fish do not meet the requirements of the market. As a result, prices are low and economic efficiency is poor.
2, according to the size of the water, determine the disinfection and fertilizer measures.
For small water surfaces, such as standard fish ponds, regular use of quicklime or bleaching powder is required for regular disinfection. The length of the disinfection interval is generally determined according to the body's thinness to ensure good water quality when the fish species are stocked. If the water surface is large, the stocking density is relatively dilute, the fish is not susceptible to disease, and it may not be sterile or fat. However, the requirement for feeding is relatively high.
3, fish species should be kept in cages or net enclosures (columns) for a few days before departure.
Because of the high density of fishes during transportation, if they are not raised before transport, they will cause unsafe performance of the fish during transportation and emit large amounts of feces. This will worsen the water quality. If transport time is long, it may cause a large amount of fish. death.
4, choose good weather transport fish species.
The temperature at the time of transportation has a great influence on fish species. When the temperature is too high, the species of fish are active, the oxygen consumption is large, and it is easy to cause the death of hypoxia; the temperature should be between 5-20°C, the temperature is high and it must be shipped. Ice cubes can be used to lower the water temperature and transport oxygenated.
5, disinfection of fish.
In particular, fish species that have been transported for a long period of time must be sterilized. They can be bathed with 3%-5% saline for 10 minutes and then watered. For large-water stocking, because the water quality is generally relatively good, many technical staff do not disinfect the stocking, in fact, in order to prevent infection, it is best to disinfect. The purpose of disinfection is to prevent the introduction of new pathogens and to prevent infection by fish injuries.
6. Be careful when catching, transporting, and launching.
In the process of catching, transporting, and launching, the operation should be gentle to avoid injury to fish. Once a fish is found to be injured, it should be taken out to avoid any loss after transport or stocking.
1, according to the conditions of the waters and sources of feed to determine the species of stocking species, specifications and quantity.
If the fish farming waters are standard fish ponds or small ponds within 3.3 hectares (50 acres), as long as there are water sources, the water quality is good, and the amount of bait suitable for feeding various fishes is sufficient, then the main fishes and the collocations are the main fishes. The principle of collocation and polyculture is to select fish of different food habits and different activities in the water layer, and also to consider the specific conditions of the pond. If the fish farming waters are large water surfaces, such as lakes, reservoirs, etc., based on experience, it is better to store fish species such as white peony, grass carp, head bream, and carp. In order to use white fleas as the dominant species, stocking species should have large specifications, generally about 20 per kilogram. The number of fish species to be placed in various waters shall be weighed and determined by a combination of factors such as the amount of plankton, benthos, aquatic grasses and other natural baits, and the funds and management levels of the purchased baits. It can also be determined according to the quantity, specifications, and specifications at the time of raising water in the waters that have been raised in recent years. If the size of the fish when the water is raised is large and much larger than the product size, the number of stocking in the second year can be more, and vice versa. The number of stocking can be reduced. At present, many farmers do not ask for quality only because of their quantity. When the water is raised, the specifications of the fish do not meet the requirements of the market. As a result, prices are low and economic efficiency is poor.
2, according to the size of the water, determine the disinfection and fertilizer measures.
For small water surfaces, such as standard fish ponds, regular use of quicklime or bleaching powder is required for regular disinfection. The length of the disinfection interval is generally determined according to the body's thinness to ensure good water quality when the fish species are stocked. If the water surface is large, the stocking density is relatively dilute, the fish is not susceptible to disease, and it may not be sterile or fat. However, the requirement for feeding is relatively high.
3, fish species should be kept in cages or net enclosures (columns) for a few days before departure.
Because of the high density of fishes during transportation, if they are not raised before transport, they will cause unsafe performance of the fish during transportation and emit large amounts of feces. This will worsen the water quality. If transport time is long, it may cause a large amount of fish. death.
4, choose good weather transport fish species.
The temperature at the time of transportation has a great influence on fish species. When the temperature is too high, the species of fish are active, the oxygen consumption is large, and it is easy to cause the death of hypoxia; the temperature should be between 5-20°C, the temperature is high and it must be shipped. Ice cubes can be used to lower the water temperature and transport oxygenated.
5, disinfection of fish.
In particular, fish species that have been transported for a long period of time must be sterilized. They can be bathed with 3%-5% saline for 10 minutes and then watered. For large-water stocking, because the water quality is generally relatively good, many technical staff do not disinfect the stocking, in fact, in order to prevent infection, it is best to disinfect. The purpose of disinfection is to prevent the introduction of new pathogens and to prevent infection by fish injuries.
6. Be careful when catching, transporting, and launching.
In the process of catching, transporting, and launching, the operation should be gentle to avoid injury to fish. Once a fish is found to be injured, it should be taken out to avoid any loss after transport or stocking.