Nutritional requirements and reproductive performance of Neomysis orientalis: Evaluating the effects of different diets

Mysids have become the preferred diet for Sepia and Hippocampus breeding due to their nutritional content and size. Despite their potential as a high-quality feed, limited literature exists on the specific nutritional needs of N. orientalis and how diet influences their reproduction. This study investigated the effects of various diets—Corethron sp., Chlorella sp., mixed algae, and flakes—on the survival, total reproductive output, and whole tissue nutritional composition of N. orientalis. The main results were as follows: 1) N. orientalis fed with Corethron sp. exhibited the highest survival (90.11 ± 5.09% at 14 d; 57.78 ± 5.09% at 21 d); 2) Significant differences in total reproductive output were observed among the dietary groups, with the mixed diet group showing the highest output (121.67 ± 5.03 ind), followed by the Corethron sp. group (102.67 ± 3.51 ind); 3) Principal component analysis revealed that the nutritional composition of mysids predominantly comprises C18:2n-6, C22:6n-3, Σn-3 PUFA, Asp, Glu, Val, Phe, and TAA; 4) Correlation analysis indicated a strong positive correlation between the dietary C18:2n-6 and Σn-3 PUFA and the survival and total reproductive output of N. orientalis. Additionally, the dietary C20:4n-6 and C20:5n-3 showed a strong positive correlation with the C22:5n-3 and Σn-3 PUFA in N. orientalis. A similar strong positive correlation was observed between dietary amino acids and those in mysids. In conclusion, the study demonstrates that different diets directly influence the nutritional composition of mysids, affecting their survival and total reproductive output during the breeding period. Consequently, Corethron sp. emerges as a suitable diet for N. orientalis, enriching C20:5n-3 and Σn-3 PUFA, which fulfills the nutritional requirements of N. orientalis during their reproductive period, thereby enhancing individual survival and reproduction.