Changes of haematological indices of grass carp, Ceteopharyngodon idella exposed to monogenean parasites, Gyrodactylus spp. and Dactylogyrus spp.

The present was carried out to investigate the effects of monogenean infection on haematological indices of grass carp, Ceteopharyngodon idella. In this regard, some haematological indices were measured in two adult groups of grass carp including healthy and infected fish. According to our results, the values of red blood cells (RBCs), haemoglobin (Hb) decreased significantly in infected fishes (P < 0.05). In contrast, the white blood cells (WBCs) values increased significantly in infected fishes (P < 0.05). In contrast, the WBC values increased significantly in infected fishes. In conclusion, our results showed that monogenean infection by Gyrodactylus spp. and Dactylogyrus spp. can affects health condition of grass carp through alternation of haematology.