There is also cannibalism, especially in the larval stage, the small ones are often swallowed by the big ones. After eating, go back to the cave or gap to have a rest. Generally, they are scattered and do not form large groups. They move to the nearshore in midsummer and to the deep water in winter, without long-distance cave trips.
Euryhaline, with salinity above 10‰, is suitable for growth. The optimum temperature is 22 ~ 28℃. Androgyny, the female matures first and has sexual transformation. That is, in the life of the same tail fish, it is female at a young age and gradually becomes male with age.
Extended data:
Natural seedling fishing
The culture of grouper still depends on the fry in natural waters. There are two fishing methods for natural seedlings. A small trawl and purse seine are used in the breeding season to catch young fish at the algae cluster on the reef edge. After primary selection, the young fish caught are cleared of other miscellaneous fish and cultured in ponds or cages.
Feed small crustaceans, young fish and minced fish twice a day. The length of fry is 2-3 cm, and the release amount of fry is 150-200 fish/m3. 1 ~ 2 months later, it is sorted according to different sizes and specifications, and gradually becomes sparse.
The other is hand fishing. Fishing includes double-door fishing or single-door fishing. Live bait is mostly used, with live shrimp as the best, followed by small fish. Hand fishing operations are mostly in reef waters, with a long operation cycle, and enter the peak season after Qingming.