Prevalence and intensity of protozoan ectoparasite infestation on nursery of humpback grouper (Cromileptes altivelis) in hatchery and floating net cage

Ectoparasites which often attack humpback groupers are protozoa from the Ciliate class, Trichodina sp. and Cryptocaryon sp. This study studied the differences in the prevalence and intensity of protozoan ectoparasites in nursery of humpback grouper in hatcheries and floating net cages. The results showed that there was a significant difference (p <0.05) between the prevalence and intensity of protozoan ectoparasites in nursery of grouper which were kept in hatchery and floating net cages. The prevalence nursery of humpback grouper infested from hatcheries and floating net cages is Trichodina sp. ectoparasites are 83.3% and 76.6%. Prevalence of Cryptocaryon sp. ectoparasites are 76.6% in hatchery and the prevalence of floating net cages is 50%. From the statistical test shows that the intensity of the Trichodina sp. ectoparasites at the hatchery is 12.76 individuals/head was significantly different (p <0.05) on the intensity of the Trichodina sp. ectoparasites. In floating net cages of 4.2 individuals/head. Meanwhile, the results of statistical tests on the intensity of ectoparasite Cryptocaryon sp. at the hatchery is 4.47 individuals/head significantly different (p <0.05) on the intensity of ectoparasites Cryptocaryon sp. in floating net cages there are 1.73 individuals/head.