683 Ectoparasitic Diseases in Freshwater Ornamental Fish and Their Treatments C.Erkin Koyuncu Department of Aquaculture, Faculty of Fisheries Mersin University TURKEY ekoyuncu@mersin.edu.tr Erol Tokşen Department of Aquaculture, Faculty of Fisheries Ege University TURKEY erol.tokşen@ege.edu.tr Abstract: Fish parasites and their effects have become increasingly visible during the latest decades inconnection with the development of fresh water ornamental Fish industries troughout the world. Diseases problem including hazards caused by parasitic organisms are the main threat to further increase of the industry. Ectoparasites are the most common and widely distributed of freshwater ornamental Fish. Such as, protozoan ectoparasites of aquarium fish (Ichthyophthirius multifiliis, Ichthyobodo necatrix, Chilodonella cyprini, Oodinium limneticum, Trichodinids); external worms of fish (Dactylogyrus extensus, Gyrodactylus bullutarudis); external crustaceans (parasitic copepods, Argulus japonicus, Argulus foliaceus, Lernaea cyprinacea).The fish louse Argulus spp. is now the main problem in cage-cultured freshwater ornamental Fish in the fresh water environment in Europa countries. Gyrodactylus bullatarudis had caused the mortality in guppy ornamental fish. White Spot Disease (Ichthyophthiriosis) occurs in ornamental fish fry interprise caused the considerable economic loss. Ornamental fish were affected heavily by ectoparasites due to the very fine structure of the skin. Ectoparasites causing in ornamental fish only kills the fish but also reduces the market value of fish. The present work aim to the parasitic diseases of freshwater ornamental fish, how they are transmitted, which effects they have on ornamental fish, how they could be diagnosed, and how they could be controlled and treated. Introduction Fish parasites and their effects have become increasingly visible during the latest decades inconnection with the development of freshwater ornamental Fish industries troughout the world. Diseases caused by parasites are widespread and cause loses of fish in intensively stocked pond and aguarium. Ectoparasites of freshwater ornamental fish come in all sizes and shapes and inculude single-celled protozoan, and mullticellular trematodes (flatworms), crustaceans and artropods (Roberts 2010). Parasites can infest the outer surface or penetrate the paranchyma of almost any tissue of the host. Fish can serve as an intermediate, paratenic (transport) or definetive host for various stages of parasites. Ectoparasitic infections in freshwater ornamentals fishes are diagnosed by wet mount cytology preparations of skin scrapes, gills biopsies, and by direct observation (macroscopic parasites) (Woo 2006, Roberts 2010). Ectoparasites are the most common and widely distributed of freshwater ornamental Fish (Tab.1). These parasites, in crowded pools and aquariums, together with increasing water temperature when appropriate conditions are found to cause large losses. Ornamental fish were affected heavily by ectoparasites due to the very fine structure of the skin. Ectoparasites causing in ornamental fish only kills the fish but also reduces the market value of fish (Mousavi 2003,Tokşen 2006, Koyuncu 2009). In this review, treatment and control of ectoparasites of freshwater ornamental fish in the recent developments were reviewed. The Study Research Significance In this study, ectoparasite of freshwater ornamental diseases and drug therapy are discussed. Ectoparasite freshwater ornamental that can be used in treatment of diseases and drugs are defined and explained the general features.