In oviparous fish larvae, the mouth-open period is a crucial physiological and metabolic switch period. To explore the molecular mechanisms involved in metabolism during this stage in Coilia nasus larvae, we performed next generation RNA-seq technology to assemble de novo a transcriptome and analyzed differential expressed genes (DEGs). In our study, 307,825 unigenes were generated. 154 genes significantly increased, and 144 genes were significantly inhibited during the mouth-open period. Metabolism-related DEGs were classified into retinol metabolism, purine metabolism, and lipid metabolism, and they were altered during this stage. These activated metabolism-related genes would contribute to eye development, cell cycle, and lipid storage. Moreover, some genes related to eye development, cell cycle, and lipid storage were detected by RT-qPCR. These results indicated that retinol metabolism, purine metabolism, and lipid metabolism were improved, and they would contribute to eye development, cell cycle, and lipid storage during the mouth-open period in C. nasus larvae. These results would contribute to comprehending the physiological and metabolic switches during the mouth-open period, and provide the theoretical basis for breeding.

在卵生鱼的幼虫中，张口期是关键的生理和代谢转换期。探讨Co虫这一阶段新陈代谢的分子机制幼虫，我们进行了下一代RNA测序技术以重新组装转录组并分析了差异表达基因（DEG）。在我们的研究中，产生了307,825个单基因。154个基因显着增加，而144个基因在张口期间受到显着抑制。代谢相关的DEGs分为视黄醇代谢，嘌呤代谢和脂质代谢，它们在此阶段发生改变。这些与代谢相关的活化基因将有助于眼睛发育，细胞周期和脂质存储。此外，通过RT-qPCR检测到一些与眼睛发育，细胞周期和脂质储存有关的基因。这些结果表明，视黄醇代谢，嘌呤代谢和脂质代谢得到改善，它们将有助于眼睛发育，细胞周期，C.鼻虫幼虫。这些结果将有助于理解张口期间的生理和代谢转换，并为繁殖提供理论依据。