The effect of different carotenoid sources on skin coloration of cultured red porgy (Pagrus pagrus)

Abstract

This study presents data on the effect of carotenoid sources on skin coloration of red porgy (Pagrus pagrus). Three experiments were conducted: in the first, fish were fed an astaxanthin (Naturose®)-supplemented diet, while the second fish received diets supplemented with β-carotene (Rovimix β-caroten®) or lycopene (Lyc-O-Mato®): Carotenoids were added to the level of 100 ppm in each diet, while a non-carotenoid-supplemented diet served as a control. In the third experiment, the effect of dietary protein/carbohydrate ratio on melanin content in the skin was investigated. For this experimentation, four diets were formulated to contain 50/23, 40/32, 30/48 and 20/59 protein/carbohydrate ratio. Naturose® astaxanthin increased total carotenoid content in the dorsal skin area while β-carotene and lycopene seem to have had no significant effect. Naturose® was the only carotenoid source that had a significant effect on skin hue, promoting a reddish coloration to the dorsal skin area and a ventral hue similar to wild red porgy. No apparent effect of carotenoid source on skin melanin content was observed. In contrast, dietary protein/carbohydrate ratio affected melanin content in the skin. The fish fed the 50/23 diet showed significantly higher values. Farmed red porgy had eight times higher dorsal-skin melanin content than wild ones.