Effect of diet enriched with Astaxanthin and Bile salt on growth and pigmentation and skin carotenoid content of Blood parrot (Cichlasoma synspilum ♀ × Cichlasoma citrinellum ♂)

This study was done to improve pigmentation rate of blood parrot by bile salt incorporation into the diet enriched with astaxanthin. The fish (mean weight 25.5±2.6 g and length 6.34±0.43 cm) were fed for 90 days using three different treatments, including control (basic diet), astaxanthin (enriched with 4g/kg astaxanthin) and astaxanthin-bile salt (enriched with 4 g and 1200 mg of astaxanthin and bile salt per kg of diet, respectively). The results showed that growth performance parameters (specific growth rates as an exception) were significantly improved in the fish fed on astaxanthin enriched diet (P<0.05). While fish fed the diet enriched with astaxanthin-bile salt did not show such an improvement (P>0.05). Colorimetric analysis showed that the period for the highest pigmentation intensity in fish fed the astaxanthin-bile salt are lower (about one-third) than the fish fed on diet enriched with astaxanthin (30 vs 90 days). At the end of the feeding trail, biochemical analysis showed that the fish fed on astaxanthin+bile salt diet had the highest skin carotenoid concentration (P<0.05). Colorimetric analysis using reflection spectroscopy showed the highest red color intensity in fish fed on the diet enriched with astaxantin-bile salt. In summary, it could be concluded that adding bile salt to the astaxantin enriched diet could improve pigment retention rate into the skin of parrot fish which rectify fish marketability.