Analysis of the physiological responses of Pacific abalone (Haliotis discus hannai) to various stressors to identify a suitable stress indicator

Abstract

AbstractThe Pacific abalone (Haliotis discus hannai) is the most economically valuable shellfish species in Northeast Asia, accounting for most of the shellfish production in South Korea. Despite the continuous improvement in the productivity of domestic abalone aquaculture, rapid seawater temperature changes caused by global warming have led to mass mortality in coastal abalone farms. Therefore, research on environmental stressors is urgently needed to prevent abalone production losses. This study analyzed the expression of heat shock protein (HSP) genes in foot muscles of H. discus hannai and metabolic parameters including glucose, lysozyme, catalase, D‐lactate, and trehalose levels in the hemolymph under acute high temperature, low temperature, low salinity, and air exposure. Quantitative reverse‐transcription polymerase chain reaction analysis showed that HSP20 expression was downregulated in all experimental groups, whereas HSP70 expression increased immediately in all experimental groups except for the low‐temperature stress group. Hemolymph analysis showed that glucose and lysozyme levels increased significantly immediately after treatment in all groups, and decreased during the recovery period. Together, the results indicate that low water temperature stress had the smallest effect on abalone among the treatments. We conclude that the other treatments acted as stressors of abalone and that HSP genes, glucose, and lysozyme can be used as stress indicators in H. discus hannai.