Journal of Scientific Research and Reports

A 75-day feeding trial assessed the growth and physiological responses of juvenile Scylla serrata offered formulated diets containing eel meal. Three experimental diets were prepared with different proportions of fish meal and defatted soybean meal: T1 (30% fish meal and 15% soybean meal), T2 (23% and 23%), and T3 (17% and 30%), respectively. Each experimental diet contained 5% eel meal, and performance was compared with a control group. Growth, feed utilisation, carcass composition, digestive enzyme activities and antioxidant enzyme activities were evaluated. Initial weights were similar among groups. Final weights were 130.29, 133.87, 128.00 and 114.36 g for the control, T1, T2 and T3 groups, respectively. Weight gain percentage and specific growth rate were significantly higher in the control, T1 and T2 groups than in T3 (p < 0.05). Feed conversion ratios were lower in these three groups, whereas feed efficiency ratios and protein efficiency ratios were higher. Protease, amylase and lipase activities followed a similar pattern. In contrast, superoxide dismutase and catalase activities in the hepatopancreas and gills were highest in T3. Carcass protein and lipid contents were also lower in T3 than in the other groups. Under the conditions examined, T2 maintained growth and physiological performance comparable to those of the control and T1 groups, whereas T3 showed less favourable responses. These findings support further assessment of eel meal-containing formulations with moderate fish-meal replacement for juvenile mud crabs.