en fish disease fish disease پژوهشي Orginal research papers The main objectives of this study were to study the parasitic infestation of Lernaea cyprinacea in 4 cyprinids from the Choghakhor Lagoon, Chaharmahal - Bakhtyari Province, west of Iran. A total of 180 cyprinids including Cyprinus carpio (n=101), Carassius auratus (n=47), Capoeta aculeata (n=10) and Alburnus alburnus (n=22) caught, and were studied for Lernaea cyprinacea infestation. Prevalence (C. carpio 61.4, C. auratus 87.2, C. aculeata 70 and A. alburnus 68.2), intensity of infection (C. carpio range 1 to 5, mean 2.1 C. auratus range 1 to 6, mean 1.9 C. aculeata range 1 to 5, mean 2.4 A. alburnus range 1 to 2, mean 1.1), and abundance (C. carpio 1.3, C. auratus 1.6, C. aculeata 1.7 and A. alburnus 0.8) varied with the fish species. A statistically significant difference was found between infestation by L. cyprinacea and fish species (p=0.01), although no statistically significant difference was found between infestation and weight, length and age of the studied fishes (p>0.05). The prevalence was also significantly different (p=0.0) in studying seasons. Population dynamics of L. cyprinacea on fish hosts was studied. The results show that the preferred site of the parasite was body lateral surfaces followed by caudal , dorsal , pectoral and anal fins (P=0.0). Lernaea cyprinacea, Fish parasite, Choghakhor Lagoon, Iran 680 688 http://jifro.ir/browse.php?a_code=A-10-600-24&slc_lang=en&sid=1 M. Raissy mehdi.raissy@iaushk.ac.ir 10031947532846007514 10031947532846007514 Yes H. R. Sohrabi 10031947532846007515 10031947532846007515 No M. Rashedi 10031947532846007516 10031947532846007516 No M. Ansari 10031947532846007517 10031947532846007517 No