Morphomolecular alterations in the skin mucosa of Atlantic salmon (Salmo salar) after exposure to peracetic acid-based disinfectant

•Atlantic salmon were exposed to therapeutic doses of peracetic acid (PAA) at 2 occasions.•Skin colour and key histological mucosal parameters were not remarkably affected by PAA treatments.•Proteolysis-related genes were modulated more remarkably during the first exposure than during re-exposure.•The magnitude of alteration associated with PAA treatment was marginal.