Marigold Petal Meal: A Natural Carotenoid Source for Pigmentation in Swordtail (Xiphophorus helleri)

Abstract

An experiment was conducted to see the effect of feeding graded levels of marigold petal meal on pigmentation of skin, growth performance, nutrient utilization and muscle biochemical composition in ornamental fish, swordtail (Xiphophorus helleri). Different iso-caloric and iso-nitrogenous experimental diets were formulated with supplementing five levels (0, 2, 4, 6 and 8%) of marigold flower meal. The experimental fish (n=225) were divided into five equal groups having three replicates under each group and fed respective experimental diets for a period of 60 days. The biochemical composition of fish muscle was similar in all the groups. Total carotenoids concentration (μg/g) in the skin of sword tail at the beginning and end of feeding was similar in control diet (2.94 vs 3.17). The supplementation of marigold petal meal in the diet significantly increased (P<0.05) the total carotenoid concentration in the muscle and skin of sword tail from 2.87 to 6.17 μg/g. Growth performance and nutrient utilization in fish were similar in all the experiment groups. The study revealed that marigold petal meal at the 4% level can be supplemented in the diet of swordtail for improvement of skin coloration through increase in the carotenoids concentration in skin without any adverse effect on body composition, growth and feed conversion efficiency.