Tilapia fry breeding technology in spring
The suitable water temperature for tilapia reproduction is 22-23°C, and natural spawning usually occurs after mid-May. In order to grab the season and make full use of light, heat, and bait resources to increase aquaculture production, it is necessary to artificially increase the temperature, intensify cultivation, and early spring propagation so that tilapia can be hatched and hatched in mid-April. The specific measures are as follows.
1. Selection and breeding of broodstock Choosing broodstock with good maturity in the middle of March will be put into the spawning pool to strengthen cultivation. The spawning pool may be used for wintering ponds. Normally, 6 broodstock are stocked per square meter of spawning pool, with a ratio of 2:1 or 3:1, while changing water regularly.
2. The warming and feeding management pool water temperature should be controlled at 23 °C above, water quality requirements of fertilizer, live, cool, feeding amount can be based on water temperature, water quality and fish growth may be. In the general cistern, the daily feeding amount is 2% of the fish body weight, and the flow pool is 3%. At the same time, we must constantly observe the activity of fish and the degree of gonadal development, and make every record.
3. Obvious differences exist in the body color of tilapia male and female fish spawning. The estrus male swims in the pool and looks for a nest. The shape of the nest is pot-shaped, with a diameter of 30-40 cm and a depth of about 10 cm. After the nest is built, the males often seduce from the female group and intercept the females into the nest. When the water temperature reaches 22-23°C, females can lay eggs. At the time of spawning, the abdomen of the female fish is close to the bottom of the burrow, and the male fish is guarded by the nest. After the female lays eggs, the female eggs are sucked into the mouth immediately, and the mandibular protrusion is saccular. The male fish immediately enters the nest and the females suck the semen into the mouth with water. The egg is fertilized in the mouth.