Supplementation of paprika as a carotenoid source in soft-dry pellets for broodstock yellowtail Seriola quinqueradiata (Temminck & Schlegel)

Abstract

This study was carried out to investigate whether readily available paprika can replace astaxanthin as a source of carotenoids in soft-dry pellets for broodstock yellowtail Seriola quinqueradiata (Temminck & Schlegel). Five months prior to spawning, 120 fish of average body weight (BW) 6.2 ± 1.5 kg were divided into three groups and fed basal soft-dry pellets (SDP), SDP supplemented with 30 mg/kg astaxanthin (a-SDP), or SDP supplemented with 2% paprika (p-SDP). Feeding was carried out in floating net cages and two spawning trials were performed. Fish were selected (five male and five female per group per trial), injected with human chorionic gonadotropin (600 IU kg−1 fish) and transferred to 100 m3 indoor concrete tanks for spawning. In trial 1, egg production during the first day of spawning was highest for the p-SDP group, followed by the a-SDP and SDP groups. For the p-SDP, a-SDP and SDP groups, fertilization rates were 76.0%, 69.7% and 61.9% and hatching rates were 75.2%, 63.9% and 59.4%, respectively. In trial 2, fertilization rates were 80.9%, 78.0% and 86.8% and hatching rates followed the same trend as in trial 1, at 61.8%, 52.9% and 37.2%, respectively. Moreover, larvae of the p-SDP groups showed better survival at day 3 after hatching. Apart from the darker yellow colour of fertilized eggs of the astaxanthin or paprika supplemented diet groups, analysis showed that carotenoids from paprika were successfully incorporated into the eggs, mainly as zeaxanthin and lutein. Paprika supplementation did not affect the fatty acid and lipid class profiles of eggs and unfed larvae. These results indicate that paprika supplementation in soft-dry pellets is effective for good quality egg production in yellowtail.