Fast and slow releasing sulphide donors engender distinct transcriptomic alterations in Atlantic salmon hepatocytes

•Sulphide (H2S) detoxification genes are ubiquitously expressed in Atlantic salmon.•Liver and mucosal organs exhibited pronounced expression of H2S detoxification genes.•Sulphide donors (SD) affected the expression of H2S detoxification and antioxidant defence genes in hepatocytes.•Prolonged but not transient exposure to SD significantly reduced hepatocyte viability and proliferation.•Genes involved in mitochondrial metabolism were downregulated by the sulphide donors.