Morphometric and molecular characterization of Dactylogyrus lamellatus isolated from farmed Grass carp, Ctenopharyngodon idella (Valenciennes, 1844), in Guilan province, Iran

Grass carp is an herbivorous species, which is actually popular in Iran. Monogenean parasites, particularly members of the family Dactylogyridae, have been one of the main causes of mortalities in Iranian fish farms and therefore they have been subject of many studies in Iran. The main aim of the present study was to describe morphological and molecular characteristics of monogenean parasites recovered from the farmed grass carp (Ctenopharyngodon idella) in the Guilan Province during 2015 to 2016. A total of 80 grass carps have been examined for infestation with monogenean parasites. 10923 Dactylogyrus species were recovered from 95% of the farmed grass carp. The parasite was first classified based on their morphological characteristics and identified as Dactylogyrus lamellatus. The parasite was then subjected to PCR and sequencing of the 28S rDNA gene. The phylogenetic tree showed that D. lamellatus genetically was similar to those previously reported from other countries and Mashhad farms in Iran.