Effect of dietary supplementation of astaxanthin and beta-carotene on colouration, growth and survival in pearlspot (Etroplus suratensis) fingerlings under controlled conditions

Abstract

The pearlspot (Etroplus suratensis) is dull greenish black color in and less attractive cichlid fish to the customer. The present study investigated the effects of different concentration of astaxanthin and beta-carotene incorporated feeds on pigmentation of E. suratensis skin and flesh. Seven carotenoid content incorporated diets were formulated at different concentrations of axtaxanthin (100 ppm, 200 ppm and 300 ppm) and beta-carotene (30 ppm,40 ppm and 50 ppm). During the experimental period (60 days), the fishes were fed at the rate of 5% of body weight per day. The highest mean weight gain was observed in fishes fed with 300 ppm of astaxanthin (24.06+0.01 g) and 50ppm of beta-carotene (21.56+0.01 g), compared to other treatments and control. Significant improvement in the growth parameters were recorded in the experimental fishes than control. The highest carotenoid content was found in fishes fed with 300 ppm of astaxanthin and 50 ppm of beta-carotene compared to other treatments and control. There was no significant difference (P>0.05) in the growth performance of fishes by dietary carotenoid supplementation. However, significant (P<0.05) difference was observed in the flesh and skin of fishes fed with 300 ppm astaxanthin and 50 ppm beta-carotene treatment. Pearlspot fingerlings fed with carotenoid content incorporated diets showed better growth performance and feed utilization. Dietary carotenoid content influenced digestive enzyme activity, haemotological and biochemical responses. In order to improve the consumer preference and the market value of E. suratensis, these flesh and skin colouration could be improved by feeding with diets containing astaxanthin (300 ppm) and beta-carotene (50 ppm).