A comprehensive analysis of hepatopancreas metabolomics and transcriptomics provides insights into the growth of three-year-old crabs (Eriocheir sinensis) under low temperature.

Low water temperature is a critical environmental factor limiting the size of cultivated aquatic individuals. However, it has found that a proportion of Eriocheir sinensis cultured in low water temperature with high-altitude can mature into three-year-old crabs, which present larger body size than conventional two-year-old crabs. Based on integrated transcriptomic and metabolomic analysis, the significantly difference focuses on metabolic pathways involving glycine, serine, and threonine metabolism, amino sugar and nucleotide sugar metabolism, cysteine and methionine metabolism, pantothenate and CoA biosynthesis, arginine and proline metabolism, and vitamin digestion and absorption. It revealed that the growth performance of three-year-old crabs is mainly regulated by improving its antioxidant defense to maintain physical fitness, while reducing protein consumption by intensifying energy supplement ability and enhancing the ability to digest and absorb nutrients at low temperature. This study provides new insights on the molecular and metabolic pathways that control E. sinensis growth at high-altitude and low water temperature, laying the theoretical basis for further artificial three-year-old crabs breeding.