Overwintering Management of Freshwater White Pomfret seedlings

Pomfret is a kind of tropical fish, its main growth temperature range is 21-32 ℃, the most suitable temperature range is 28-30 ℃, Pomfret begins to eat a small amount when the water temperature is 16 ℃, the fish body balance is out of balance at 12 ℃, and causes death at 10 ℃. In the process of overwintering, the water temperature is too low, which will lead to the weakening of fish disease resistance, especially in the early overwintering period and spring overwintering period. October generally enters the critical period of overwintering breeding of seedlings. Therefore, we must do a good job in the management before overwintering:

First, clear the pond

The pond for raising Pomfret seedlings overwintering generally requires 2 mu, and the water depth is more than 2 meters, in order to ensure the stability of the water temperature. Before releasing the seedlings, the pond must be cleared to kill the pests in the pond. Generally, 200-250 jin / mu of quicklime should be used to clear the pond, and 30 ml / mu of chlorpromazine should be sprinkled at the same time to kill the diseases and insect pests, and the seedlings can be put in a week later.

Second, feeding

From October to November before overwintering, Pomfret seedlings need to be fortified before they are put into the overwintering pond to strengthen their physique and improve their disease resistance. They are generally fed with high-energy feed, such as wheat husk and bean cake, which can be fed at 5% of the fish's body weight every day.

III. Stocking capacity

The seedling density put into the overwintering pond is generally controlled at about 30,000 / mu, in case the density is too high, the water quality is easy to deteriorate, and about 500 tilapia fry can be released per mu.

IV. Prevention of fish diseases

White Pomfret seedlings in overwintering ponds must pay attention to fish disease prevention, because once the disease occurs, treatment is difficult, prevention should be strengthened in order to ensure safe overwintering.

1. When stocking seedlings in the overwintering pond, careful operation must be taken to avoid fish injury. Before entering the overwintering pond, soak in 3% salt water for 10-15 minutes to kill the pests on the body surface of fish fry and prevent them from being brought into the overwintering pond.

2. Prevent grass carp from mixing into the overwintering pond, because grass carp can easily be parasitized in the intestines by Jiujiang head tapeworm, and the eggs hatched into coccidiosis, its intermediate host is Cyclops, and white Pomfret seedlings feed on Cyclops, which can cause a large number of parasitic intestines and stomach in Jiujiang head trough and die.

3. Use a drug to prevent it once a week, which can be carried out alternately with bleach and mercurous nitrate by:

(1) hang bags with bleach and hang 100g of each bag near the food market for prevention.

(2) sprinkle 1 gram per cubic meter of bleach (containing more than 20% chlorine) in the whole pool.

(3) Mercury nitrate, 0.1 g per cubic water, sprinkled throughout the pool.