Occurrence and intensity of parasites in goldfish (Carassius auratus L.) from Guilan province fish ponds, north Iran

In this survey 109 specimens of goldfish (Carassius auratus) were collected from Guilan fish ponds during 2012-13. After recording biometric characteristics, common parasitology methods were used. In the present study 11 parasite species were recovered from goldfish. Parasitofauna consisted of two protozoans: Ichthyophthirius multifiliis and Trichodina sp.; one digenean trematodes: Diplostomum spathaceum; six monogenean trematodes: Dactylogyrus vastator, Dactylogyrus formosus, Dactylogyrus baueri, Dactylogyrus anchoratus and Gyrodactylus sp.; one crustacean: copepodid stage of Lernaea cyprinacea and one nematodes larvae. All the monogeneans found during the current study are considered new locality records for goldfish in Guilan province, Iran. Mean intensity of infection and abundances of parasite species (with prevalences >10%) among seasons were tested by the Kruskal-Wallis test (KW, multiple comparisons) and Conover-Inman test. Results have shown that monogeneans had the highest prevalence values (49.54%) in goldfish in Guilan fish ponds.