Prevalence and Intensity of Anchor Worm (Lernaea cyprinacea L.) Ectoparasite in Koi Fish (Cyprinus carpio L.) at Bantul Koi Farm D.I. Yogyakarta

One obstacle in the cultivation of Koi fish (Cyprinus carpio L.) in Bantul Koi Farm D.I. Yogyakarta is a disease caused by parasites of anchor worms (Lernaea cyprinacea L.). Therefore, this study observed the prevalence and intensity of anchor worm ectoparasites in Koi fish in Bantul Koi Farm. Taking fish samples using the purposive sampling technique. Each of three fish individuals was taken as replication from three populations, namely Showa, Shiro and Saragoi, with a size of 28- 36  cm.  The  prevalence  and  intensity  are  determined  by  the observation method by counting the number of anchor worms found. Inferential  statistics  carried  out  data  analysis  of  the  number  of ectoparasites in each population. The results showed that the highest anchor tick ectoparasite prevalence was found in the Shiro population (100%) and the lowest in the Saragoi population (33%). The highest intensity was  in  the  Showa  population  (4  individu/ fish),  and  the lowest was in the Shiro population (2 individu/ fish), although all of them were in a low category. The highest number of ectoparasites was obtained from the Showa population (8 individuals) and the lowest in the  Saragoi  population  (3  individuals),  but  it  was  not  statistically significant. The high prevalence in the Shiro population is due to the high stocking density. Anchor flea ectoparasites attacked the skin and fins of Koi fish and were not found to attack gills. The conclusion of this study is the highest prevalence of anchor tick ectoparasites was found in  the  Shiro  population  (100%)  and  the  lowest  in  the  Saragoi population  (33%).  The  highest  intensity  was  found  in  the  Showa population (4 individu/ fish) and the lowest in the Shiro population (2 individu/ fish), even though all of them were in a low category.