Effect of Insect Meals on the Growth Efficiency, Survival and Total Carotenoid Content of an Ornamental Fish Xiphophorus maculatus (Gunther, 1866)

To evaluate the effects of three non-conventional insects (cricket, grasshopper and mealworm) and commercial diet (control) on growth, survival and total carotenoid content of ornamental fish, platy (Xiphophorus maculatus), a feeding trial was conducted in Zoology laboratory, Vidyasagar College, West Bengal, India, between November 2021 and May 2022. A total of 250 platy juveniles (0.04±0.002 gm) were stocked in 12 glass aquariums with 20 fishes for each experimental feed set. Each experimental diet was made per triplicate. The growth efficiency parameters of platy fish in terms of weight gain percentage, specific growth rate (SGR), feed conversion ratio (FCR) were measured at the end of the study period. Protein content in percent is significantly higher in mealworm (46±0.58) and then in grasshopper (42.50±0.29). Final weight of fishes was significantly higher in mealworm fed sets (2.134gm±0.008) and lower in commercial meal fed sets (0.827gm±0.003). The lowest FCR was found in commercial diet (0.458±0.002) and best FCR values was found in cricket diet (0.280±0.001). Higher value of SGR was obtained in mealworm fed sets (2.209±0.002) and lower SGR was in commercial diet (1.683±0.002). Mean survival percentage was 90% in mealworm diet and lowest survival value was 55% at commercial diet. Carotenoid content in fish body was significantly higher in mealworm diet (9.23μg/g±0.071), while lowest was observed in commercial diet (0.47μg/g±0.001). Present study shows that insect diets were better than commercial diet, but mealworm diet was better to increase survival and carotenoid content in X. maculatus.