Mohamad Hosein Ebreahimi; Fatemeh Abbassi
Abstract
Skin coloration patterns in fish are of great physiological, behavioral and ecological importance, can be considered as an index of animal welfare in aquaculture and as an important quality factor for the retail value. In the present study the effect of different doses (0, 300, 400 and 1000 mg/kg of ...
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Skin coloration patterns in fish are of great physiological, behavioral and ecological importance, can be considered as an index of animal welfare in aquaculture and as an important quality factor for the retail value. In the present study the effect of different doses (0, 300, 400 and 1000 mg/kg of diet) of commercial methyltestosterone on three-dimensional characteristics of skin color appearance (lightness — L*, hue — H ◦ab and chroma —C◦ab) with a new index named Entire Color Index (ECI) were investigated. For data analyzing, because of the nature of the color factors, circular distribution was used. The lightness of the caudal fin was significantly (p<0.05) higher than body in all the doses except 1000 mg/kg. The lightness of the body area primarily decreased and then increased in 1000 mg/kg. With increasing the doses, the tendency to the redness Hue was increased. In addition we had significant difference in Hue values between body and caudal fin area. As a result, with increasing the dose of hormone, red pigments, and therefore attractiveness of the male were increased and this differences in color factors could be resulted to the increasing the retail values.
