Floc contribution on spawning performance of blue shrimp Litopenaeus stylirostris
Résumé
The floc system has been successfully applied for shrimp grow-out, but little is known about floc contribution on reproductive performance. In a 30-day trial, spawning performance of broodstock was evaluated in floc and earthen ponds. Floc spawners achieved better results (P < 0.05) compared with pond spawners in terms of number of spawns per ablated female (2.9 vs. 1.3), spawns per spawning female (3.6 vs. 2.4) and number of consecutive maturation (average of 3.6 times compared with 2.5 times in ponds females). Latency period was lower for floc spawners (7.4 days) than pond spawners (10.7 days) (P < 0.05). The percentage of females that spawned at least once were higher in floc (77.1%) when compared with pond spawners (53.8%) (P < 0.05). Number of eggs per spawn per g of spawner's body weight and female mortality presented no significant differences between treatments (P > 0.05). Biochemical analysis as a nutritional status indicator showed no difference between treatments in hepatopancreas (P > 0.05), with the exception of lowest values of acylglycerides and acylglycerides/total soluble protein ratio in floc females ovary (P < 0.05). Results evidenced better overall spawning performance for L. stylirostris broodstock produced under floc condition than in earthen ponds.