A parasitological investigation was done on175 specimens. Infections of A. brama orientalis were analyzed according to the age and sex. The fish also were examined for evaluation changes of haematological parameters in relation to parasitic infection. Four parasites were found, including—Caryophyllaeus laticeps and Ligula intestinalis (Cestoda), Diplostomum spathaceum(Platyhelminthes) and Trichodina sp. (Ciliophora). Among identified parasites maximum prevalence and mean intensity were related to Ligula intestinalis and Caryophyllaeus laticeps respectively. The values of prevalence and mean intensity showed significant differences among ages. Our results revealed prevalence, mean intensity and abundance had not significant difference between males and females. Parasite infection provoked reduction (P\0.05) in haematocrit, mean cell volume and lymphocyte. On the other hand, significant increase (P\0.05) in white blood cell (WBC), mean cell haemoglobin concentration and neutrophil in blood of infected fish was observed. Significant differences were detected for the WBC, lymphocyte and neutrophil (infected versus uninfected by Trichodina sp., Diplostomum spathaceum and Caryophyllaeus laticeps). In addition to WBC and lymphocytes, significant change wasobserved for the haemoglobin (Hb) (infected versus uninfected by Ligula intestinalis(.
