Non-targeted metabolomics revealed the effect of starvation to juvenile Onychostoma sima liver.

Artificial breeding and releasing can effectively restore fishery resources. However, it is important to note that released juvenile fish were highly susceptible to starvation during their adaptation to the natural environment. This study investigated the metabolomic changes in the liver of Onychostoma sima after 14 days using ultra-high pressure liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) analysis under starvation exposure. The experiment was divided into a control group (C Group) and a starvation group (S Group), with six biological replicates in each group and one fish per replicate. The results indicated significant changes in the starvation group compared to the control group, as demonstrated by the principal component analysis (PCA) score plots and orthogonal partial least squares discriminant analysis (OPLS-DA). The 297 differential metabolites screened were mainly involved in the metabolism of organic acids and derivatives, and lipids and lipid-like molecules. Furthermore, KEGG results revealed that differential metabolites were primarily enriched in 33 metabolic pathways. The majority of the amino acid metabolic pathways in the liver were significantly affected by starvation stress. Moreover, biosynthesis of amino acids, protein digestion and absorption, and mineral absorption were upregulated, while glycerophospholipid metabolism and the hedgehog signaling pathway were downregulated in response to energy demands during starvation. In conclusion, these findings provide physiological insights into the metabolism of juvenile O. sima under starvation stress, offering new perspectives for the optimization of fish proliferation and release technology.