Ectoparasites Of The Sea Bass In Boka Kotorska Bay

Abstract

The objective of this work has been to examine the presence, identify ectoparasite species and extensity and intensity of infection of Sea Bass (Dicentrarchus labrax) cultivated in cage systems of breeding in Boka Kotorska Bay during a production cycle. Additionally, pathomorphological and pathohistological changes in infected fish caused by parasites have been examined. The examination covered both juveniles and adult fish. The examinations were performed during three seasons: in the spring, summer and autumn of 2009. By examining ectoparasitic fauna in cage systems of Cogi in Boka Kotorska Bay, we found the presence of the following parasites: Diplectanum aequans, Trichodina spp., Amyloodinium ocellatum. The most important ectoparasitic species in Sea Bass in our examination was Diplectanum aequans – monogenean gill parasite. This parasite in a case of big infestation can cause disease diplectanosis. The extensity of infection caused by identified ectoparasite species varied depending on the season, but the biggest was during the summer, while the intensity was generally low. Therefore, no significant damage was noted in the cage systems. Minor pathomorphological and pathohistological changes were noted in the infected fish. Due to low intensity of parasitic fauna, no specific therapy administration was required. However, more intensive administration of prophylactic measures and regular veterinary surveillance could result in significant reduction in the presence of parasites and, consequently, more efficient performance.