The technology provided by the Maonan Sangao High Breeding Breeding Base advances the emergence time of Tilapia by one month. The Maonan Sangao High Breeding Breeding Base in Maoming City is a seedling planting base in Guangdong Province that breeds Oxya. The base has a water surface area of ​​770 mu. There are 100,000 jins for Ouni and the four home-breeding parents, of which the Ouni parents are 50,000. jin. In 2002, more than 80 million Otoni fish were bred. In September 2002, it was approved by the Guangdong Provincial Aquatic Provenance Breeding and Approved Committee as the provincial-level (Maoming) tilapia post-cultivation field and actively played the technical advantages and resource advantages of the base. It introduced and digested domestic and foreign breeding techniques and researched the promotion of Onifish. The early propagation technology promoted the early emergence of tilapia and achieved remarkable results. The seedling time was February 28. (In the same period, the seedling time in 2002 was March 28). The breeding period was one month earlier than that of Tilapia in Tong Tong during the same period, and a historic breakthrough was made in the western part of Guangdong. Its main technical measures are:
First, adhere to the long-term intensive cultivation of broodstock, prompting broodstock early in sexual maturity.
After the winter broodstock stopped spawning, it continued to maintain intensive cultivation. According to the water temperature situation, it is still time to quantitatively deliver a sufficient amount of concentrated feed, so that the parents can accumulate nutrient reserves in the body to ensure the development of gonads. At the appropriate conditions such as temperature can be spawned at any time.
Second, early selection of broodstock pairing pond training, prompting the broodstock nesting spawning.
According to the habit of Oini fish having free pairing to spawn, changing the habit of picking pairs of fish before spawning earlier, before the wintering (ie, the selection of all Ouni parents from November 15 to 25 last year) Into the pond winter cultivation. Selection of broodstock earlier than in previous years for a season, this is conducive to early broodstock nesting into the breeding season.
Third, the water temperature, promote gonads mature.
The plastic film scaffolding was built in the Owen parents' wintering pond, which not only ensured the safe wintering of the Oani parents, but also improved the pond water temperature. During the cold wave period, the minimum water temperature was kept above 18 degrees Celsius, and the water temperature increased by 3-5 degrees Celsius. The higher water temperature promotes the gonad development of Ouni's parents.
Fourth, regular filling with new water to promote gonad development.
Aoni's pro-bench pond keeps its water level low in winter, makes full use of sunshine, and raises the water temperature of the pond water. When it encounters a cold wave, it fills the water before the cold wave arrives to prevent the cold from overwintering, and then lowers the water level after the cold wave. When the water temperature is above 19 degrees Celsius, the new water is filled once a week, and the water filling volume is increased by about 30 cm from the original water level. Filling with new water can promote gonadal development and improve the water environment.
V. Pond management is conducted as usual.
Through the above five measures, the parental gonads of Onifish were maintained in a good state of development in the winter. After the winter, ovulation began to occur in the spring, and the seedlings were raised on March 13 and 2.2 million oyster fry were bred. With the advancement of science and technology, the early emergence of Oonia fry was promoted and the success was achieved.