Dietary supplementation with chitin and chitosan on haematology and innate immune response in Epinephelus bruneus against Philasterides dicentrarchi

► The study investigated the effect of chitin and chitosan diet in grouper against parasite. ► RBC, WBC, Hb levels, lymphocytes, monocytes, and neutrophils significantly increased. ► Phagocytic, respiratory burst, complement, antiprotease and α2-macroglobulin significantly enhanced. ► Total protein, lysozyme, and myeloperoxidase activities significantly enhanced. ► This study suggested that chitin or chitosan diets positively enhanced immune response.