Pomphorhynchus laevis is a common fish parasite in Europe which has been reported from Acipenser stellatus, Barbus capito, Barbus lacerta, Barbus mursa and Onchorhynchus mykiss in Iran. In a survey on the aquaculture potential of Gamasiab River in Hamedan Province, endemic fish parasites were investigated in summer and autumn 2008. After recording biometric characteristics, common necropsy and parasitology methods were used. Live acantho-cephalans were relaxed in distilled water at 4 ºC for 1 h and fixed in 10% hot buffered formalin. All specimens fixed in 10% formalin were stained with aqueous acetocarmine, dehydrated and mounted in Permount. The worms were identified using parasite identification keys. A total of 36 individuals of Chub, Squalius cephalus, were inves-tigated and 459 individuals of Pomphorhinchus laevis were recovered from intestine of 32 fish specimens. The prev-alence mean intensity and mean abundance of P. laevis were %88.9, 14.3 and 12.7, respectively. The maximum number of the parasite recorded in a five years old fish (403gr in weight) was 130 plerocercoids. Chub, Squalius cephalus, is reported for the first time as a new host record for P. laevis in Iran.
