Tieliang Li ,Chuan He ,Zhihong Ma ,Wei Xing ,Na Jiang ,Wentong Li ,Xiangjun Sun ,Lin Luo *
A feeding experiment was carried out to determine the effects of dietary carotenoid source on body color, skin and scale pigmentation, antioxidant responses of blood porrot (Cichlasoma synspilum ♀ × Cichlasoma citrinellum ♂). Seven experimental diets were formulated as following: the control diet without carotenoids; PO diet with 4.0 g/kg paprika oleoresin, HP diet with 2.0 g/kg Haematococcus pluvialis, PR diet with 2.0 g/kg Phaffia rhodozyma, AS diet with 0.4 g/kg synthetic astaxanthin, CA diet with 1.0 g/kg β-carotene and POL diet with 2.0 g/kg paprika oleoresin + 3.0 g/kg lutein. Each experimental diet was fed to triplicate groups of fish to visual satiation twice per day for 8 weeks. The results showed that AS diet turn fish body red higher and sooner, followed by PR diet and HP diet, successively (P < 0.05). PO and CA had no significant effect on improving body color, but POL diet can turn fish color yellow effectively (P < 0.05). Astaxanthin concentration in diet is positively correlated with redness a*, but negatively with lightness L*. Diet lutein is positive linear correlation with yellowness b*. All carotenoids can significantly reduce plasma superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and lipid peroxide (LPO) level, but increase total antioxidant capacity (T-AOC). The present results suggest that dietary inclusion of 0.4 g/kg synthetic astaxanthin can improve body color effectively and quickly, and all test carotenoid source can increase antioxidant activities of blood parrot.