effect of different mating period to breeding performance of red tilapia Hybrid Broodstock

Siti Norita M*, Mumtaziah A.H, Nurazaidah, M and Mohd Fariduddin O
 
Freshwater Fisheries Research Division, FRI Glami Lemi, Titi, 71650 Jelebu, Negeri Sembilan, Malaysia
ctnorita@dof.gov.my ;  noritapppat@gmail.com

The present study was conducted to evaluate the effect of mating period on the seed production of red tilapia hybrid broodstock, Oreochromis spp. under hatchery system. Females broodstock with mean body weights of 215.0 ± 50.0 were individually tagged and stocked in six different resting (R) and mating (M) period (10R:18M, 12R:16M, 14R:14M; 16R:12M, 18R:10M, 20R:8M) at a male : female ratio of 1:2 in 1.0 × 3.0 × 0.50 m (W × L × H) fiberglass tanks. Fecundity (eggs/fry per spawn) and development stage removed from individual incubating broodfish at specified interharvest intervals (28 days) was monitored for 4 months. The results showed no significant different in total seed production and seed production/body weight. However higher spawning synchrony discovered in shorter resting period (10R:18M, 12R:16M and 14R:14M) than longer resting period of 20R:10M and 18R:10M (Fig 1). The mean percentage of seeds in yolk-sac and swim-up fry stages was highest at 12R:16M and 10R:18M (Fig. 2). The percent of hatchability decreased with eggs than yolk-sac developmental stages. However, the hatching rate was not affected by mating period. Numbers of eggs produced were higher compared to fry/yolk-sac per spawn implying that development stage of egg was influenced by mating period. Allowing female broostock to remain undisturbed for a longer period in tanks may lead to inhibition of spawning activity which might be related to the absorption of eggs for growth. Egg and yolk-sac/fry yields for red tilapia averaged 6.86 ± 2.0 eggs/g female/spawn and 5.1 ± 1.7 yolks/g female/spawn; respectively. This data could be adopted in operating broodstock multiplication center (BMC) for better seed production and might have important implications for broodstock management in the commercial hatcheries.