Optimal tuna oil and astaxanthin for growth and survival of juvenile spotted babylon, Babylonia areolata were determined. The experimental diets consisted of 4 levels of tuna oil (TO) 7, 5, 3 and 1 g/100 g diet and 4 levels of astaxanthin (AS) 0, 100, 200 and 500 ppm. Total diet treatments were 16 formulas. Initial juveniles spotted babylon average shell length of 0.5± 0.01 cm were fed the experimental diets for 120 days. Thirty spotted babylon were reared in a 16x14x19 cm plastic basket raised in a closed recirculating water system. Three replications of each experimental diet were conducted. The result indicated that at 120 days babylon fed diet formula 2 (TO7:AS100) tuna oil 7 g/100 g diet and astaxanthin 100 ppm. showed the best average shell length, weight was significantly higher than those fed on other diet (P<0.05) and specific growth rate (SGR), feed conversion ratio (FCR). At the end of the experiment, all diet treatments showed 100 % survival of the snail. The level of astaxanthin in babylon increased significantly related to astaxanthin concentrations in the diet.
