Abstract
The Lernaeid parasites, Lernaea spp, are crustacean ectoparasites that occur in a variety of fishes worldwide. In the present study, Shizothorax zarudnyi (n = 1,500) were examined during August 2012 to 2013 to determine the prevalence of Lernaeid parasites at one Species fish of Chahnimeh lakes Sistan, Iran. Two species of the genus Lernaea; L. cyprinacea and L. polymorpha, were recorded. The overall prevalence rates of L. cyprinacea and L. polymorpha were 15.47 and 10.20 % respectively. The relationship between body weight and Lernaeid parasites showed that prevalence of L. cyprinacea and L. polymorpha was highest in weight group of 250-400 g and lowest in weight group of 500-700 g. The overall percentage of infestations in study was the highest (42.5 %) in summer, moderate (33.6 %) in spring and the lowest (17.25 and 6.62 %) in the autumn and winter season, respectively. The number of detected Lernaeid parasites and infested fish were 6,140 and 800 respectively. The mean intensity of infestation was 7.68. There was significant correlation between parasite prevalence and intensity with host weight (P = 0.000). Knowledge of the prevalence of Lernaeid parasites and current Lernaea species will help to minimize the economic losses in the fish industry, evaluate infestation potential and control programs, especially for other fishes.