Investigation of parasites of pikes (Esox lucius Linnaeus, 1785) from Chamkhale River, Anzali and Amirkelayeh wetlands, Iran.

To investigate the health status, the parasite diversity and abundance were studied in three pike populations. For this purpose, totally 90 fish were caught from three natural habitats of pike including Chamkhale River, Anzali and Amirkelayeh wetlands, Iran. After biometry and age determination, fish were dissected and parasites were investigated in intestine, gill and eye. According to results, five parasite species were identified in whole body of pikes including Eustrongylides exises, Raphidascaris acus and Triaeophorus crassus in intestine, Tetraonchus monenteron in gill and Diplostomum spathaceum in eye. The highest values of quantitative indices of parasite population [i.e. incidence percent (86.66 %), mean intensity (60.83 ± 39.92), mean abundance (58.14 ± 34.6) and abundance range (1-232)] were recorded for T. monenteron in all three sampling regions. The lowest values of these quantitative indices were found for D. spathaceum, E. exises and Tetraonchus crassus in Anzali wetland, Chamkhale River and Amirkelayeh wetland respectively. In 2, 3 and 4 years old pikes, T. monenteron had the highest values of quantitative indices of parasite population. In conclusion, our results showed that Anzali wetland have more parasite pollution compared to other sampling regions. This may be due to the more rapid eutrophication in this wetland compared to Amirkelayeh wetland and Chamkhale River.