Cultivation of juvenile Colossoma macropomum in different colored tanks in recirculating aquaculture system (RAS): Effects on performance, metabolism and skin pigmentation

Abstract

This study assessed the effects of different tank colors (white, blue, green and black) on the performance, metabolism and skin pigmentation of Colossoma macropomum cultivated in recirculating aquaculture system (RAS). In Phase 1 of the experiment, 224 juvenile C. macropomum (4.04 ± 0.32 g) were cultivated for a period of 30 days at a density of 0.5 juveniles/L. In Phase 2 of the experiment, the juveniles (34.32 ± 12.14 g) were cultivated within each treatment for another 20 days at a density of 0.25 juveniles/L. Biometrics were performed for all juveniles after 30 and 50 days of cultivation. Blood was also collected after 50 days of cultivation and skin pigmentation analysis and determination of the hepatosomatic index (HIS) and lipid concentration in the liver (HL) were performed. Juveniles grown in white tanks had the highest final weight (FW), total length (TL) and weight gain (WG) among treatments at the end of the both phases. At the end of Phase 2, juveniles grown in white tanks had higher levels of triglycerides (p < 0.05) than juveniles of the other treatments. Juveniles grown in black tanks had darker pigmentation and higher hemoglobin and total plasma protein (p < 0.05) than the other treatments. Tank color was found to affect the performance, pigmentation and metabolism of juvenile C. macropomum cultivated in RAS, with white tanks providing the best environment for cultivation and welfare.