Mass Cultivation Technology of Summer Flowers of Myrtle (Megalobrama tricornis, Megalobrama amblycephala)

Bream (blunt snout bream, blunt snout snout bream) is a kind of high quality freshwater fish, which is not only an excellent species for pond culture, but also suitable for stocking on large water surface, making use of its characteristics of easy formation of natural population to achieve the purpose of resource protection and proliferation. In this paper, the techniques of mass cultivation of summer flowers of mackerel are introduced as follows:

I. conditions of summer flower cultivation pond

Summer flower cultivation pond requires adequate water source, non-pollution water quality and convenient injection and drainage. The area should not be too large. Generally, it is appropriate to have a water depth of 1-1.2 meters and a water depth of 3 mu. If the pond does not leak, the bottom is flatter and has the right amount of silt.

Second, prepare before stocking

1. Clear the pond and disinfect: drain the water before stocking, remove too much silt or weeds, repair and strengthen the ridge of the pond and plug the loophole. 7-10 days before seeding, water was injected with 5-10cm and sprinkled with 50-80kg quicklime per mu, and the sediment was turned over to mix well with lime slurry; 6-10kg bleach could also be used to sprinkle in the whole pond to kill wild miscellaneous fish and pathogens.

2. Proper fertilizer and water: 4-5 days before the fry goes into the pond, 50-60cm should be injected into the pond. The water should be filtered through sieve silk to prevent wild fish and other harmful organisms from entering the pond. At the same time, 100-150kg of rotten human and animal manure and an appropriate amount of chemical fertilizer were applied per mu as base fertilizer to cultivate plankton so that the fish fry had palatable bait in the pond.

3. Test the water and pull the net: a "test of the water" should be carried out the day before the seedling release to check whether the drugs and toxicity of the culture pond have disappeared. At the same time, a small number of frog eggs, small miscellaneous fish and enemy organisms that may exist in the pond can be pulled out by using a dense eye net for 1 or 2 times.

III. Fish fry restocking

As the fish spray is very delicate, the transportation and seedling release of the fish should be carried out carefully. If you buy spray, you should first put the nylon bag containing spray into the pond water and soak for 20-30 minutes, waiting for the water temperature inside and outside the bag to be basically the same before releasing seedlings. The stocking density is generally 10-150000 fish per mu, and the same batch of fish fry should be released in each pond. The time of seedling release is generally chosen in the morning on a sunny day. If you encounter windy weather, you should plant seedlings in the windward place of the pond.

IV. Feeding and management

1. Bait fertilization: the fish fry began to sprinkle soybean milk as soon as they got into the pond. Soak the soybeans in water for 5-6 hours, then grind 1 kilogram of dried soybeans into 15-20kg soy milk. Sprinkle the ground soy milk in time. Use 2-3 kilograms of dried soybeans per mu of water every day and sprinkle them twice in the morning and afternoon. Soymilk should be poured evenly and foggy around the edge of the pond, and fermented human and animal dung should be applied every 3-5 days according to the water quality of the pond. In the later stage of cultivation, when the size of bream fry reaches 2cm, the amount of soybean milk should be gradually reduced, but the amount of concentrate feed (such as secondary powder, fine bran, etc.) should be increased, generally twice a day, 1-1.5kg per mu, in order to ensure sufficient nutritional requirements of fish fry, promote their rapid growth and enhance their physique. However, whether it is baiting or fertilization, it is necessary to increase or decrease flexibly according to the weather conditions, that is, in case of rainy or muggy weather, the amount of feeding should be reduced appropriately.

2, regulation of water quality: the water level of fish fry just after entering the pond is controlled at 50-60cm, and the water level is raised continuously with the growth of fish fry, generally every 3-5 days, the amount of water injection is mainly determined according to the water quality fertility, that is, when the water is thin, more fertilizer is applied and less water is injected, if the water is more than fertilizer, the water level is gradually increased to the highest, and the water level is always maintained in the pond water with a transparency of about 25-30cm to ensure that the water quality is "fat, alive and cool".

3. Strengthen disease prevention: persist in patrolling the pond twice every morning and evening, observe the activities of fish fry and the changes of water quality in detail, and avoid the occurrence of floating head hypoxia. It is necessary to control the amount of fertilizer and feed and adjust the water quality to prevent the deterioration of water quality due to sudden changes in weather or excessive fertilization, and to prevent the occurrence of common diseases such as bubble disease and horse racing disease. If the water quality is aging in the later stage of cultivation, in addition to timely water injection, quicklime can also be sprinkled to improve the water quality. In addition, if frog eggs, water snakes and other enemy organisms and foreign bodies are found on the water surface during the daily pond patrol, they should be removed in time.

Fifth, pull the net to exercise

Mackerel seedlings after 25-30 days of cultivation, generally can meet the 3cm specifications, at this time should be timely out of the pond. Because the fish summer flowers are good at jumping, impatient, and easy to stick to the net, the operation out of the pond is slightly careless, often causing damage and affecting the survival rate out of the pond. Therefore, in addition to paying attention to adequate bait in the later stage of cultivation to enhance the physique of summer flowers, we should also carry out indispensable net-pulling exercise before coming out of the pond. The net-drawing exercise should be carried out in the morning on a sunny day, once a day or every other day. After the fish fry are slightly densed for the first time, the fish fry should be put back in place, or they should be pulled back and forth twice in the pond with a thin net. After the second net-drawing exercise, the summer flowers can be concentrated in the net, or they can be moved into long cages. The length of the dense time depends on the tolerance of the fish, but the net-pulling operation should be very careful not to make the fish stick the net and leave the water. In this way, after 3-4 net-drawing exercises, the fish fry have enhanced their ability to resist hypoxia and endure density. if it is a long-distance transportation, it is best to move the summer flowers into the net cage of clear water for 3-5 hours to discharge feces and excessive mucus. Improve the survival rate of transportation out of the pond.