Identification of ectoparasites in grouper fish (Epinephelus spp.) From 2 commercial farms in Kelantan

Ectoparasitic infestation is the presence of parasites outside the body of host that depend on their host for sustenance, maturation and reproduction. It is one of the most concerning problems in fish farming especially in commercial fish farms because this condition can affect the quality and the production of the fish. This study was conducted to identify the ectoparasites that infest the grouper fish in two commercial fish farms located in Bachok and Pengkalan Chepa, Kelantan.A total of 30 grouper fish were collected in this study. Physical examination was conducted on the fish and ectoparasites were collected for identification. A Chi square test was performed to analyze the data. As for the result, the ectoparasites such as Zeylanicobdella sp. (marine leech), Dactylogyrus sp. (monogenean) and Halacarid sp. (marine mites). were identified from the grouper fish. The prevalence of Zeylanicobdella sp. was 80.0% and 0.0% in Farm A and Farm B, respectively. While the both prevalence of Dactylogyrus sp. and Halacarid sp. was 100.0% in Farm A and 0.0% in Farm B, respectively. The presence of ectoparasites is associated with the lower salinity water. Based on the water quality assessment, the lower salinity can contribute to poor water quality which can induce the infestation of ectoparasites. In this study, Zeylanicobdella sp was detected on the skin and gills with prevalence rate of 20.0% and 6.0%, respectively. Dactylogyrus sp. and Halacarid sp. were detected in the mouth. The prevalence rate of Dactylogyrus sp. was 30.0% on the skin while 33.3% for both gills and mouth. The number of Halacarid sp. was lower at the gills and mouth with prevalence rate of 30.0% than the prevalence on the skin (33.3%). As a conclusion, only three ectoparasite genus were identified infesting the fish in Farm A, while no ectoparasites was identified in Farm B. The common sites of ectoparasite infestations were skin, gills and mouth.
Keywords: Ectoparasites, grouper fish, identification, water quality