Effects of replacing fish meal with Tympanotonus fuscatus meal on the growth and survival of Nile tilapia (Oreochromis niloticus Linnaeus, 1758) fry

Abstract

This study was conducted to evaluate the effects of replacing fish meal with Tympanotonus fuscatus meal in the diet of tilapia fry (Oreochromis niloticus). The experiment was carried out on 180 fry with an initial average weight of 0.25 g, distributed in nine 60-liter fiberglass tanks at a density of 20 fry per tank. Three diets were formulated: a control diet based on fish meal (R1), and two diets (R2) and (R3) in which fish meal was replaced by 50% and 100% Tympanotonus fuscatus meal, respectively. The fish were fed for 60 days with rations of 10%, 8%, 6%, and 4%. Growth, survival, and feed conversion parameters were evaluated. The best growth performance was observed with diet R1, followed by diet R2, while diet R3 showed poor performance. The lowest feed conversion ratio (FCR) was recorded with diet R1 (2.22), reflecting superior feed efficiency compared to the other diets. Overall, survival rates were satisfactory (100% to 80%). Biochemical analysis of crude protein content showed that there was no statistically significant difference between the initial fish and those tested. There was no statistically significant difference in lipid content between the initial fish and those on the diets (R1 and R3), and it was higher in fish fed diet R2. This could be explained by the incorporation rate. No statistically significant difference in ash content was observed in the test fish. These results indicated that Tympanotonus fuscatus meal could replace up to 50% of fish meal without negatively affecting the growth, survival, or flesh quality of tilapia.