Founder silver crucian carp is a fish that is resistant to low temperature and low oxygen. Therefore, it is easier and safer to protect the species during winter.
1. Over the winter preservation of the pool
Customs in the south of the Yangtze River in autumn (before and after October) and pool winter. The first purpose is to list the fish out of the market; the second is to renovate the ponds. At this time, we can combine the timing of commercial fish listing and Jingtang out of the pool, select qualified broodstock according to the broodstock standards, and use the pool for 500-1000 per acre for the winter in the pool. The pool water level should be maintained at 1.5 meters or more to facilitate the use in breeding in the following spring. The pool can also be fed during the winter when the water temperature is appropriate (usually the silver carp can also feed at a water temperature of about 10°C) to promote further development of the gonads; at the same time, it is necessary to strengthen management.
2. Measures for safe wintering of fish.
(1) Over the winter pool clear pond, disinfection. 10 to 15 days before the release of the fish, the pool water should be drained as much as possible, and dried for 3 to 7 days. The whole pool should be splashed with 50 to 75 kg of lime per acre. In some areas, if original pond water is used for wintering, the original pond water should be drained 2/3 to 1/2, then lime water (about 1 meter water depth, 15 to 25 kg per mu) and bleaching powder (to make pool water into available chlorine 1) Mg/L concentration) Sterilization. After 1 to 2 days, it is best to use crystals of trichlorfon throughout the pool, so that the pool water concentration of 1 ~ 2 mg / l, to prevent disease (plankton) disease prevention.
(2) Water injection and replenishment. Overwintering pools should use well water or reservoir water, non-polluting river water, and deepen to the maximum depth before freezing. At this time, pool water should be kept lean and the transparency should be more than 80 cm. After freezing in the winter, it is necessary to fill the water frequently. Adjust the water's fatness by water injection and keep the water from collapsing. At least one or two injections of water are needed per week.
(3) Control of zooplankton. During the winter, a large number of rotifers and sword leeches are frequently harvested, and phytoplankton are ingested. The amount of phytoplankton in the pool water is too small, and the dissolved oxygen in the water is reduced. At this time, crystals of trichlorfon are used to circulate the pool water. Sprinkle) to make the pool water concentration 1 mg/l.
(4) Prevention of fish diseases. During the wintering period, fish diseases also occur from time to time, and timely treatment is needed according to the type of fish disease, such as hanging bags, Quanchiposa and other methods. However, fish diseases during wintering mainly occur after thawing, and a large number of deaths may occur. At this time, fish should be caught in time and the fish body should be disinfected before being put into a cultivation pond for cultivation and continued treatment.
