Parasitic disease in Koi fish (Cyprinus carpio) in freshwater ponds with different densities in Sukabumi, West Java

Abstract Koi fish (Cyprinus carpio) is one type of freshwater ornamental fish that is in high demand, and easy to culture. The main problem that often becomes an obstacle in fish farming is the emergence of parasitic diseases. The aimed of the study was to determine the types of parasites in Koi fish (C. carpio) rearing ponds with different fish densities in Sukabumi, West Java. The method used in this study is a survey method. Fish samples were taken every week in three different ponds, namely the cage pond (150 fish/m2), pond 10 (66 fish/m2), and pond B7 (33 fish/m2) usingthePurposive Random Samplingmethod. Parasite found in Koi fish (C. carpio) isArgulussp.,Trichodinasp.,Gyrodactylussp.,Dactylogyrussp.,Ichtyophtiriius multifili,andGlossatellasp. on the gills and body surfaces of the fish. The types of parasites found in all ponds wereTrichodinasp., andDactylogyrussp. The highest prevalence ofTrichodinasp., andDactylogirussp. was found in cage ponds 80% and 60%, respectively. The highestTrichodinaandDactylogirusinfestations were found in cage ponds with an average value of five individuals/fish and seven individuals/fish.