Artificial breeding of turbot seedlings

Females of wild turbot matured in 3rd instar, mature males in 2nd instar, and matured in 5-8 months. Cultured turbot fish males mature at age 1, and females can reach sexual maturity at 2 years of age. The gonad development of turbot is particularly sensitive to light. Artificially cultivated broodstock can obtain mature eggs from 1 to 10 months under the condition of controlled light. Broodstock can be obtained through import or artificial breeding, and fish that grow fast, have strong physique, no attachment organisms and rickets, and no "whitening" should be selected as broodstock. The broodstock breeding process requires a water temperature of 12 to 17°C to ensure that the water is fresh and the feed is nutritious. The indoor pool raises the general density of broodstock 2~3 tails/m2.
Although large batches of broodstock can grow eggs and obtain fertilized eggs naturally, most of them still adopt artificial insemination. Fertilized eggs can be hatched in open or closed water, with water temperatures in the range of 12-17°C. The newly hatched larvae have a cultivation density of 5 to 20 tails per liter. The source of the water should be filtered seawater or groundwater. It is best to be sterilized by ultraviolet rays. The light source is an artificial light source, which is connected for 16 hours per day with a surface illumination of 200-2000 Lux. Micro-inflated during the cultivation, the water temperature gradually increased to 20 °C. The larvae start feeding 2 to 3 days after hatching, 2 times a day. Two-day-olds hatched and hatched, the optimum food biota width was 144 μm, and it increased to 225 μm by 10 days of age. The rotifers can be initially fed with a density of 5 to 10 cells/mL. Artemia nauplii are fed for 6 to 10 days after hatching, and the density is 0.5 to 1 cell/mL for 20 to 25 days. The rotifers and Artemia fed by unicellular algae and emulsified fish oil should be strengthened and disinfected. Feeding together with Artemia-rich diets and Artemia can reduce the number and cost of live baits.
In addition, the natural copepods have more nutrients than fortified rotifers and Artemia, and are also ideal feed for turbot seedlings. When larvae are about 20 mm in length, artificial diets can be fed to gradually change their diet. The protein content of artificial diet of turbot juveniles should be greater than 40%, the suitable content is 45~47%, the fat should be greater than 8%, the suitable content is 13~15%, the suitable moisture content is 10~11%, and the ash content should be Less than 12%.