Alternations in the liver metabolome, skin and serum antioxidant function of silver pomfret (Pampus Argenteus) is induced by jellyfish feeding

Many fish species are known to feed on jellyfish. Herein, we observed the effects of jellyfish feeding on silver pomfret using gas chromatography tandem time-of-flight mass spectrometry (GC-TOF–MS) based on metabolomics. We studied the effects of feeding on jellyfish on skin and serum immune of silver pomfret. Healthy silver pomfret (initial weight, 13.40 ± 1.565 g) was divided into two groups: control and feeding. The pomfrets were fed jellyfish at 2, 6, 12, 24, and 72 h, and samples were obtained. Statistical analysis revealed that after jellyfish feeding, most serum immune indicators did not show a significant change; however, skin immune indicators indicated that silver pomfret elicit a stress response on encountering jellyfish, gradually adapting to their presence. We therefore conducted further experiments involving two groups: group A, which was not fed any extra jellyfish, and group B, which was fed extra jellyfish (approximately 10% weight of silver pomfret) every day for 60 days. Orthogonal partial least squares discriminant analysis led to the identification of stronger biomarkers, with the liver metabolome showing obvious variations between the groups (group B vs. A). After feeding jellyfish by silver pomfret, some amino acids, amines, and unsaturated fatty acids in the liver tissue showed a significant increase. Our results, thus, not only reveal changes in physiological indices of silver pomfret after feeding on jellyfish but also provide a new idea for further optimizing the feed formula for silver pomfret culture.