Reproductive performance of Nile tilapia (Oreochromis niloticus) in successive spawnings in biofloc technology (BFT)

The objective of this study was to evaluate the reproductive performance of Nile tilapia (Oreochromis niloticus) in successive spawnings maintained in biofloc technology (BFT). A total of 30 broodstock (females: 29.1±67.39 g and 25.9±1.84 cm; males: 31.4±62.47 g and 27.4±1.93 cm) were distributed into five experimental units, each with a volume of 1 m3, containing six broodstock at a sex ratio of 2:1 (4 females:2 males). The experimental period was five weeks. Water quality were monitored and kept for the species in BFT, with an average temperature of 28.59 ± 0.22 ºC, settleable solids below 50 mL/L, and alkalinity above 100 mg/L. Among the 11 females (55.0%) that spawned for the first time, seven (63.6%) spawned again, with intervals ranging from 14 to 27 days between spawnings. No changes were observed in the reproductive variables, except for a reduction in the minor egg diameter in the second spawning. These results indicate that rearing Nile tilapia females in BFT promotes successive spawnings within a short period, suggesting it is a viable and efficient alternative to the traditional breeding system using hapas installed in earthen ponds.