Biological aspects of Thai red tilapia reproduction
1993
Parnsri Jarimopas | Panu Tavarutmaneegul | Anusin Inkuan (Department of Fisheries, Bangkok (Thailand). National Inland Fisheries Inst.)
Biological aspects of Thai red tilapia reproduction was studied in 4 experiments 1. Natural breeding of red tilapia, eighteen 50 square m concrete ponds were used for breeding red tilapia by 3 sizes of brooders, 750-900 g, 250-450 g and 150-200 g and 3 stocking ratios of female and male (1:1, 2:1, 3:2) with two replicates. 2. Gonadal development was determined using histological techniques. Gonadal somatic index (GSI), condition factor (CF), fecundity, sex ratio and size of mature eggs were determined. 3. comparison of artificial and natural breeding of Thai red tilapia after spawning 7 days 4. Embryology of Thai red tilapia was studied. 1. The brooder size 250-450 g and the ratio of female and male 1:1 produced highest amount of fry (11,905.83 fry/month) 2. The early maturity of Thai red tilapia was 4 months of age (% CF female = 6.22+-1.32 and % CF male = 4.52+-0.67) and 6 months old of these fish was the optimum maturity (% GSI female = 2.79+-1.03 and % GSI male = 2.38+-1.24). Fecundity was 560-1,990 eggs from female weight 62-175 g. Sex ratio of female and male was 1:1.2, R** (2) of female and male were 0.864 and 0.9033 showed high relationship between weight and length. 3. Artificial breedings of Thai red tilapia was succeeded by inject LHRH analog 10 ug/1 kg female. The results showed 1 % hatched out when the natural breeding of red tilapia was about 80 % hatched out. Natural breeding of red tilapia could produce amount of fry more than artificial breeding 4. Embryology of Thai red tilapia showed hatch out period about 70 hours and the egg size was about 2.5-3.0 mm in diameter (average 2.9+-0.14 mm)
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