The immune responses of mucus from the skin of turbot (Scophthalmus maximus) was studied in reference to changing water temperature.Groups of fish were exposed to a programmed increase of 3℃ per 48 hours,until the experimental water temperatures of 16,20,23,25,27,or 28 ℃ were reached.After 48 hours at the relevant temperature the expressions of immune-related factors were determined,including immunoglobulin M (IgM),IL-1β,hepcidins,transferrin,lysozyme,acid/alkaline phosphatase and superoxide dismutase using RT-PCR and spectrophotometric methods.Significant changes in mucus immunity were observed,which paralleled those previously reported for serum in other fish species.Hence,it is suggested that the serum and mucus immune system have a similar regulatory system.