Effect of different rearing conditions on body lipid composition of greater amberjack broodstock (Seriola dumerili)

Abstract

The aim of this study was to assess the effect of two rearing conditions: outdoor environment with great volume tanks (500 m3) and low stocking density (~0.4 kg m−3); and indoor environment with smaller volume tanks (10 m3) and higher stocking density (~5 kg m−3), on muscle, liver and ovary lipid composition of Seriola dumerili broodstock born in captivity. The rearing conditions tested seem to affect the pattern of lipid body deposition in broodstock fish of S. dumerili, increasing the muscle and liver triacylglycerides (TG) accumulation of fish kept under indoor conditions, probably due to reduced energy expenditure in swimming, with some variations in the fatty acid profile that may respond to the differences in the culture conditions tested. No significant differences were found for Gonadosomatic Index (GSI) or ovary lipid deposition between groups in this study, which may suggest that the conditions tested do not have a major effect on ovary development. However, one season later the females kept under outdoor conditions released eggs spontaneously, whereas those kept under indoor conditions did not spawn, suggesting that the conditions tested actually have an effect on the broodstock's reproductive fitness. More studies are needed in order to evaluate whether the conditions tested have or not any influence on ovary development.