Palaemon and artemia supplemented diet enhances sea bass, Dicentrarchus labrax, broodstock reproductive performance and egg quality

Abstract

The effects of palaemon and artemia dried biomass dietary supplementation were studied on European Sea bass, Dicentrarchus labrax, broodstock egg quality, reproductive performance, sexual hormones and plasma proteins, lipids levels and lysozyme activity. The broodstock (1.36 ± 0.06 kg female−1 and 1.01 ± 0.11 kg male−1) were fed on three experimental diets as follows: basal diet (BD), palaemon-supplemented diet (PSD; 7.5 %) and artemia-supplemented diet (ASD; 2.5 %) for six weeks, besides one meal day−1 of sardine for all treatments. Then, the fish were subjected to hormonal-induced spawning with LHRHa to assure maturation and synchronous ovulation. The results revealed a significant (P < 0.05) increment in egg diameter by 15.3 and 9.6 % and oil droplet size by 9.87 and 5.09 % in broodstock fed on PSD and ASD supplemented diets, respectively, than the control group. Meanwhile, feeding on PSD and ASD significantly reduced the percentage of eggs with multi-oil droplet and non-viable eggs. The relative fecundity of PSD and ASD groups was increased by 7.53 and 20.02 % than the fish fed the BD. There were significant (P < 0.05) improvements in fertilization percentage, hatching percentage and reproductive hormones of broodstock fed the crustacean supplemented diets compared to the control. Therefore, palaemon and artemia dried biomass supplementation in the diets of D. labrax broodstock is recommended for improving reproductive performance and egg quality of sea bass, D. labrax.