Document Type : Primary Research paper
Skin coloration has a key role in ornamental fish trade. The amount of carotenoid pigments has a decisive influence on the color of muscle and skin of edible and ornamental fish. Also, there is a need to add carotenoids in the diet of cultured fish. Live foods especially Artemia play an important role in ornamental fish feeding regarding growth and skin color and thus marketing. In this study, the effects of different diets including concentrate, 67% concentrate and 33% frozen earthworm, 67% concentrate and 33% frozen Artemia urmiana as well as 67% concentrate and 33% frozen cow heart on total carotenoids and carotenoid pigments of Oscar fish skin was studied. A total of 360 Oscar fish with initial weight of approximately 1.6 g were cultured for 2 months in 4 feeding treatments, each in 3 replicates. The total carotenoids, astaxanthin, cantaxanthin and β-Carotene contents of the fish were analyzed. Results indicated that in all treatments asthaxanthin was the highest amount of carotenoid pigmentation of Oscar skin. Adding Artemia urmiana in the diet induced the higher total carotenoid and asthaxanthin levels in the skin of Oscar fish.