New record of digenean species in two mugilid fish (Chelon auratus and Chelon saliens, Risso, 1810) in southern Caspian Sea, Iran

The present study was carried out on digenean infection in two species of mugilid fish (Chelon auratus and Chelon saliens, Risso, 1810) in southern coast of Caspian Sea. One hundred and ninty eight fishes were totally studied. We identified the digenetic trematodes of three families, Haploporidae (adult Digenea), Heterophyidae (Metacercariae), and Diplostomidae (Metacercariae). Eyes, gills, stomach, intestine and pyloric caeca of fishes were infected with Diplostomidae (Diplostomum spathaceum), Heterophyidae (Ascocotyle (Phagicola) longa and Ascocotyle sp.), Haploporidae (Saccocoelium obesum and S. tensum), respectively. The results revealed that the stomach was the most infected organ (P=57%), and there was a significant difference between mean intensity of infection and sampling stations in Haploporidae (X2= 11.6, df= 3, p= 0.009) and Heterophyidae (X2= 10.2, df= 2, p=0.006). There was no significant difference between mean intensity of infection in three years and fish genders. Ascocotyle (Phagicola) longa and Saccocoelium tensum are reported for the first time in Iran. Another noticeable point is that the digenean parasites, which are prevalent in mullets, can cause disease in fishes. They are zoonotic (Ascocotyle (Phagicola) longa) and are important in point of view of ecology, economy and public health.