Effects of natural carotenoids on the body coloration and growth performance of Blue Gourami fish (Trichogaster trichopterus)

The effect of natural carotenoid on body coloration and growth of Blue Gourami (Trichogaster trichopterus) was investigated using china rose petal (T1), marigold petal (T2), and carrot (T3). Sources were incorporated with fish feed with four treatments, including T0 control treatment (without natural carotenoid sources) at a 15% ratio. Fishes were purchased and conditioned for two weeks and then randomly distributed among the 12 plastic tanks, and stocking density was maintained at eight fishes/tank. Fishes were fed twice/daily with four different treatments for eight weeks. Sampling was done every week and carotenoid contents, weight, and length measurements were recorded. The average final weights in four treatments were found 5.455±0.821 gm, 4.504±0.2196 gm, 4.764±0.727 gm, and 3.776±0.418 gm in treatments T0, T1, T2, and T3, respectively. In the case of weight gain, a higher result was found in T0 (5.455±0.821 gm). Mean final lengths obtained were 4.094±0.250 cm, 4.005±0.233 cm, 4.083-0.297 cm, and 4.083±0.311 cm, respectively. The average final carotenoid absorptions of the fishes in four treatments were 0.1226±0.0115 mg/100 kg, 0.1296±0.0169mg/100 kg, 0.1669±0.0298 mg/100 kg, and 0.1487±0.0228 mg/100 kg in treatments T0, T1, T2 and T3, respectively. T2 treatments (marigold) had the highest carotenoids gain. The highest survival rate (100%) was observed at T2. Study suggested that marigold petal could be used to make natural color enhancer feeds at a cheaper cost.