Adequate n-3 LC-PUFA levels in broodstock diets optimize reproductive performance in GnRH injected greater amberjack (Seriola dumerili) equaling to spontaneously spawning broodstock

Abstract

Dietary lipids and fatty acids composition play an important role in the reproductive processes, embryo development and larval survival in marine fish. Long-chain polyunsaturated fatty acids (LC-PUFA) are especially important for egg and larval quality. The main objective of the present study was to evaluate the effects of increasing dietary n-3 LC-PUFA levels on spawning performance and egg quality of greater amberjack (Seriola dumerili). Sixteen mature broodfish were distributed in four 40 m3 circular tanks and fed four diets containing different levels of n-3 LC-PUFA: diet D1 with 1% of the dry weight basis (dw), diet D2 with 1.7% dw, diet D3 with 2.3% dw and diet D4 with 3% dw. The fecundity was significantly higher (P < .05) in broodstock fed D2. Moreover, a higher fertilization rate (P < .05) was obtained from broodstock fed D2 (91.8 ± 3.1%) and D1 (86.3 ± 1.7%) in comparison to those fed D3 (69.0 ± 7.4%) and D4 (52.4 ± 10.6%). The same trend was found in egg viability at 24 h, hatching and larval survival rates, where highest (P < .05) when broodstock were fed D1 and D2. In addition, fertilization, hatching rates and larval survival at 1- and 3-days post-hatching showed a negative correlation with dietary n-3 LC-PUFA. The fatty acid composition of eggs showed marked differences, reflecting the influence of fatty acid profiles in the broodstock diets. Based on the overall results the recommended dietary n-3 LC-PUFA level for greater amberjack broodstock suggested is between 1 and 1.7% dw.