White-leg shrimp (Litopenaeus vannamei) reared in indoor super-intensive recirculation systems are often pale in color. This phenomenon is mainly attributed to insufficient inclusion of pigments, especially astaxanthin, in the shrimp. This study was therefore aimed at improving the shrimp's pigmentation through supplement with astaxanthin in the diet.
Diets supplemented with 0, 40, and 120 mg astaxanthin / 100 g, denoted the control, A40, and A120 groups, respectively, were fed to juvenile shrimp for 8 weeks. No differences (p > 0.05) were found in average body weights, specific growth rates, feed conversion rates, or survival rates among the shrimp fed those three diets. After microwave cooking, control shrimp were pale while A40 shrimp and A120 shrimp were reddish. Carotenoid concentrations in the head and shell of A40 shrimp and A120 shrimp were significantly (p < 0.05) higher than those of the white-leg shrimp from the market; however, there was no difference in carotenoid concentration in tail muscle.
Results of this study indicated that white-leg shrimp fed a diet supplemented with 40 mg astaxanthin / 100 g for 4 weeks could obtain coloration comparable to that of the shrimp sold in the market, which had been reared in outdoor ponds.