The effect of green, red and brown macroalgae extract on skin color of ornamental fish, Labidochromisc aeruleus

Due to growing interest in aquarium keeping, ornamental fish industry is receiving increasing attention these days. Successful ornamental fish trade depends on pr oducing animals of good size and bright colors, that directly linked to the commercial value (1). Electric yellow cichlid (Labidochromiscaeruleus) is a freshwater species from the family Cichlidae. Aquarium fish fail to m aintain the skin coloration as a result of carotenoid deprivation, which negatively affects consumer acceptance. Fish cannot sy nthesize carotenoids de novo (2) and must acquire them directly from dietary sources. T herefore, natural carotenoids from crustacean, algae, bacteria and plants, are commonly used in fish diets to enhance pigmentation (3, 4). The purpose of this study was to evaluate the skin color of Labidochromiscaeruleu sfed the diets supplemented with extracts de rived from brown macroalgaSargassumbovea num, red macroalgaGracilariapersica and green macroalgaEntromorphaintestinalis. 144 fish were randomly distributed into 12 tank s and fed on diets containing 1000 mg ext racts of macroalgae for 8 weeks. To measure the skin color, fish from each tank were randomly selected at the end of experimental period. They were individually anesthetized wi th clove oil and photographed by Canon EO S 600 camera in a box (40 × 40 × 40) in d arkness. CIELab colorimetric method, which is based on L*a*b* model, was used for det ermining the changes in skin pigmentation of fish. In this model, a* extends from green to re d and b* from blue to yellow, and L* is the am ount of lightness. Inclusion of macroalgal extracts i n the diet resulted in higher a* (redness) and b* (yellowness) values compared to t he control group.Moreover, fish fed with brown alga extract produced the lowest b*. These results suggest that macroalgalextracts, especially E. intestinalis extract, can be used as feed additive for enhancing pigmentation in electric yellow cichlid.

Due to growing interest in aquarium keeping, ornamental fish industry is receiving increasing attention these days. Successful ornamental fish trade depends on pr oducing animals of good size and bright colors, that directly linked to the commercial value (1). Electric yellow cichlid (Labidochromiscaeruleus) is a freshwater species from the family Cichlidae. Aquarium fish fail to m aintain the skin coloration as a result of carotenoid deprivation, which negatively affects consumer acceptance. Fish cannot sy nthesize carotenoids de novo (2) and must acquire them directly from dietary sources. T herefore, natural carotenoids from crustacean, algae, bacteria and plants, are commonly used in fish diets to enhance pigmentation (3, 4). The purpose of this study was to evaluate the skin color of Labidochromiscaeruleu sfed the diets supplemented with extracts de rived from brown macroalgaSargassumbovea num, red macroalgaGracilariapersica and green macroalgaEntromorphaintestinalis. 144 fish were randomly distributed into 12 tank s and fed on diets containing 1000 mg ext racts of macroalgae for 8 weeks. To measure the skin color, fish from each tank were randomly selected at the end of experimental period. They were individually anesthetized wi th clove oil and photographed by Canon EO S 600 camera in a box (40 × 40 × 40) in d arkness. CIELab colorimetric method, which is based on L*a*b* model, was used for det ermining the changes in skin pigmentation of fish. In this model, a* extends from green to re d and b* from blue to yellow, and L* is the am ount of lightness. Inclusion of macroalgal extracts i n the diet resulted in higher a* (redness) and b* (yellowness) values compared to t he control group.Moreover, fish fed with brown alga extract produced the lowest b*. These results suggest that macroalgalextracts, especially E. intestinalis extract, can be used as feed additive for enhancing pigmentation in electric yellow cichlid.