文献类型：期刊文献

英文题名：Long-term crowding reshapes energy allocation and metabolism in pearl gentian grouper (Epinephelus fuscoguttatus ♀ × E. lanceolatus ♂): Evidence from energy budget, physiology and transcriptomics

作者：Liu, Zuqiang[1];Zhao, Haixiang[1];Tao, Yi[1];Chen, Mengrui[1];You, Xinxin[2,3];Li, Xian[1,4]

机构：[1]Ocean Univ China, Fisheries Coll, Key Lab Mariculture, Minist Educ, Qingdao 266001, Peoples R China;[2]Guangdong Ocean Univ, Fisheries Coll, Zhanjiang 524088, Peoples R China;[3]Guangdong Dabaihui Marine Technol Grp Co Ltd, Shenzhen 518083, Peoples R China;[4]Shandong Key Lab Green Mariculture & Smart Fisheri, Qingdao 266003, Peoples R China

年份：2027

卷号：626

外文期刊名：AQUACULTURE

收录：SCI-EXPANDED(收录号：WOS:001826367600001)、、WOS

基金：This study was supported by the National Key Research and Devel-opment Program of China (grant number: 2024YFD2400101) .

语种：英文

外文关键词：Pearl gentian grouper; Crowding stress; Energy budget; Transcriptomics; Hepatic metabolic remodeling

外文摘要：Intensive aquaculture is widely used in grouper culture, yet the physiological basis by which long-term crowding constrains growth remains insufficiently understood. In this study, pearl gentian grouper were exposed to four stocking densities (5, 10, 20, and 40 kg/m3) for a 45-day crowding period, followed by a 14-day energy-budget trial under the corresponding densities, to investigate how chronic crowding reshapes energy allocation and hepatic energy metabolism. An integrated framework combining growth performance, whole-animal energy budget analysis, serum biochemistry, hepatic enzyme assays, and liver transcriptomics was applied. Chronic crowding significantly reduced total energy intake and growth energy deposition, while increasing the relative contribution of fecal and excretory losses to the overall energy budget. Notably, the proportion retained in growth was optimal at 10 kg/m3 but significantly reduced in the 20 and 40 kg/m3 groups, indicating a compromised efficiency of energy retention for somatic growth under severe crowding. At the metabolic level, serum glucose (Glu) and lactate dehydrogenase (LDH) increased with crowding intensity, accompanied by enhanced hepatic hexokinase (HK) and LDH activities. Glycogen phosphorylase (GPa), glycogen synthase (GS), malate dehydrogenase (MDH), and superoxide dismutase (SOD) showed non-linear responses, suggesting intensified carbohydrate turnover and glycogen mobilization, coupled with limited aerobic and antioxidant compensation under severe crowding. Transcriptomic analyses further revealed coordinated regulation of genes and pathways involved in carbohydrate metabolism, lipid catabolism, amino acid utilization, and energy-related signaling. Progressive upregulation and downregulation of distinct metabolic modules indicated remodeling of hepatic energy metabolism in response to crowding. Collectively, these findings demonstrate that long-term crowding suppresses growth in pearl gentian grouper through reorganization of energy acquisition, loss, and hepatic substrate utilization. This study provides a physiological basis for stocking-density optimization in intensive grouper culture.