How to ensure the Survival rate of "Water spray" Fish fry in clear Water Pond

Shuihua Xiatang

After artificial running water environment, the fertilized eggs of fish develop into horizontal swimming larvae after a certain period of time under appropriate water temperature, dissolved oxygen, water quality and other conditions, which we used to call "splash". During the horizontal swimming period, the swimming ability of the "splash" larvae is poor, and the feeding ability is not strong, so they can only selectively swallow the small particles around the cleft mouth which are smaller than the cleft mouth. The "splash" develops rapidly from the horizontal swimming period of passive ingestion to the active feeding period of strong swimming ability. During this period, the nutritional supply for the growth and development of "splash" is very special, and the remaining yolk in the body has a certain supporting ability. as long as it is ensured that the "splash" can get food and nutrition in time before the consumption of nutrients in the body, it can ensure continued survival and growth. One of the keys to ensuring the survival rate of "splash" is to grasp the reasonable opportunity for "splash" to go into the pond, that is, to comprehensively consider many factors such as transportation and weather, so as to ensure that when "splash" goes into the pond, it has a certain swimming ability and nutrition supply in the body.

When the "water spray" goes into the pond, the plankton biomass in the pond water is relatively small, which requires the breeders to provide appropriate food for the "water spray" in time. Therefore, it is particularly important for "water spray" to feed part of the egg yolk or sprinkle soybean milk immediately before going into the pond. In fact, the first food intake of "Shuihua" in the pond is very small, and there is a lack of habit of cruising along the edge. Generally, one hundred and fifteen million seedlings per mu are fed with 3 kilograms of dried bean mushroom milk a day. Twice a day, soybean milk will be integrated into the water body to play the role of fertilizer and water.

After many practices, it is found that the "water spray" culture pond is generally about 3 mu, the shape is regular, the bottom is flat, and the bottom mud is about 10 cm. The area is too small, the water quality is not easy to control, the survival rate of fish fry is low, the area is too large, and the production management is troublesome. The water depth of "splash" when entering the pond had better be controlled at 60-80 cm, and the water should be deeper when the temperature is low.

"Shuihua" can apply a small amount of tender Artemisia grass or rotten manure (500 jin / mu and 300 jin / mu) on the same day, which is not only conducive to the rapid production of fish fry Peng natural bait, but also will not cause excessive stress.

When the conditions of "splash" are appropriate, the growth and development of "splash" is very fast, and it also has considerable adaptability. if the weather is normal and feeding is reasonable, after 15 to 20 days, "splash" can develop three-body length of about 3 centimeters. Its feeding habits are close to the stage of its adult summer flower fish, and the survival rate can reach 40% and 50%. At this time, the water surface can no longer meet its growth needs, so it should be divided into ponds in time, otherwise it will affect the growth and survival. Full preparation should be made before the pond is divided. Generally, the fish fry should be trained for 2 or 3 times before the pond, in order to improve the adaptability of the fish fry to the net, so as to avoid the seedling body damage caused by the high water temperature and Jiang Yue of the fry.