Comparison of Growth Performance and Muscle Nutrition Levels of Juvenile Siniperca scherzeri Fed on an Iced Trash Fish Diet and a Formulated Diet

Abstract

To assess the possibility of using a formulated diet instead of an iced trash fish diet for feeding spotted mandarin fish (Siniperca scherzeri), a 20-week feeding trial was conducted. The objective of the study was to examine the effects of the formulated diet (FG) and the iced trash fish diet (XG) on the growth performance and muscle nutrient composition of the fish. The results showed that the spotted mandarin fish fed with an XG had slightly higher survival rates, weight gain rate, fullness, hepatic index, and viscera index compared to those fed with an FG, although the differences were not significant (p > 0.05). Additionally, in terms of muscle composition, the FG group had higher levels of crude protein and ash content in the fish muscle compared to the XG group (p < 0.05). On the other hand, the crude fat content showed the opposite trend. Among the seventeen amino acids analyzed, only lysine and proline levels differed significantly between the FG and XG groups (p < 0.05). In terms of muscle-hydrolyzed fatty acids, fifteen fatty acids were detected in both groups, with arachidonic acid being exclusive to the FG group. Furthermore, significant differences in the levels of thirteen fatty acids were observed between the two groups (p < 0.05). The FG group had lower levels of saturated fatty acids compared to the XG group (p < 0.05), while monounsaturated fatty acids, polyunsaturated fatty acids, and EPA + DHA contents were higher. This study demonstrates the potential of using a formulated diet as a substitute for an iced trash fish diet in the rearing of spotted mandarin fish. However, further optimization of the formulated diet is necessary to improve the growth of spotted mandarin fish in future research.