Effects of Environmentally Friendly Aquaculture Chamber Coatings on Enzyme Activities, Histology, and Transcriptome in the Liver of Larimichthys crocea

Aquaculture vessels have emerged as a sustainable alternative to traditional offshore aquaculture. However, the biological impacts of protective coatings used for vessel interiors are still poorly understood. This study assessed acute stress responses of Larimichthys crocea to epoxy-based aquaculture coatings using actual culture (1-fold) and high-exposure (80-fold) concentrations. Liver analyses included antioxidant enzymes, histopathology, and transcriptomics over 12–96 h. Firstly, the effect of the 80-fold concentration group on the activities of catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD) was more significant in the liver of L. crocea compared to the 1-fold concentration group. Similarly, histological observations revealed that the 80-fold concentration group produced more significant pathological changes in the liver than the 1-fold concentration group, including hepatocyte damage and vacuolization. Subsequently, through high-throughput sequencing, a total of 714.02 million clean reads were obtained, with 693.71 million of these reads successfully mapped onto the reference genome of L. crocea, identifying 13,709 differentially expressed genes (DEGs). KEGG pathway enrichment analysis showed that many DEGs following coating-treated were involved in protein processing in endoplasmic reticulum, oxidative phosphorylation, cytokine-cytokine receptor interaction, FoxO signaling pathway, and toll-like receptor signaling pathway. Finally, fifteen DEGs were selected for quantitative real-time PCR (qRT-PCR) analysis, and the results showed a significant correlation with RNA-seq results, verifying the reliability and accuracy of the high-throughput sequencing data. This study preliminarily revealed the stress responses induced by aquaculture vessel coatings in L. crocea and provided fundamental data into the scientific use of coatings on aquaculture vessels.