Prevalensi Ektoparasit pada Benih Ikan Koi Cyprinus rubrofuscus (Lacepede, 1803) di Sentra Budidaya Kabupaten Blitar

The problem of koi fish farming in Blitar Regency that is causing concern and has not been resolved a disease caused by ectoparasites. purpose this study was to observe the types ectoparasites prevalence parasites attack cultivation centers Regency. This type research descriptive with survey method approach. sampled were fingerlings measuring 7-15 cm Kohaku, Tancho, Ogon, Utsuri varieties three individuals each. Sampling using purposive sampling technique. Examination carried out cutting body parts (fins, gill lamellae, tail), then placing them on glass slide, dripping distilled water, covering cover glass, observing under microscope. results examination analyzed descriptively quantitatively. data obtained tabulated tables graphs paired related literacy. showed there 5 ectoparasites, namely: Lerneaea sp., Argulus Trichodina Dactylogyrus Gyrodactylus different numbers each variety. highest 4 Ogon variety (66.6%) very frequent infection category, lowest (33%) general category. amounting 66.6% (very infections) 3 individual parasites, 33% -66.6% (general infections - frequent) 7 individuals.