Title : Identification of Gyrodactylus ectoparasites in some of the Iranian warm water fish farms by PCR of the 5.8S and ITS2 segment of ribosomal DNA (Monogenea, Gyrodactylidae)
Following the gradual daily loss of fish fry in a few fish farms , 413 fish of 5 different species were sampled of some farms in Guilan province. After preparing wet mounts of skin and gills, Gyrodactylus isolates were fixed by Ammonium picrate glycerin. After photographing with a microscope ,morphometric assessments were performed on captured images. for molecular investigation the genomic DNA was extracted from one parasite specimen and 5.8SrDNA and ITS2 region of Gyrodactylus specimens were amplified by related primers in PCR. Purified fragments of PCR products were sequenced from both forward and reverse sites of each PCR product. The acquired sequences were subjected to a nucleotide Basic Local Alignment Search Tool (BLAST) in NCBI GenBank to confirm the Gyrodactylus species. The only Gyrodactylus species in skin of Common carp, Silver carp and Big head carp was G. sprostonae. These isolates were deposited in GenBank with accession numbers MF480475, MG210580 and MG238547 respectively. The prevalence and intensity of G. sprostonae was limited. In this study 70.71% of goldfish, Carassius auratus, were infected with Gyrodactylus on their skin. Morphometric evaluation of these parasite showed that its species was Gyrodactylus kobayashii and molecular research also confirmed this. The obtained sequence was deposited in GenBank with accession number MZ148586. The mean intensity of G. kobayashii was 26 by range 5-379 in each fish.
Key words: Guilan, Iran, Fish, molecular, Gyrodactylus,