Survey on ectoparasite occurrence of fish groupers sent to Fish Quarantine Agency for diseases inspection

Abstract

Abstract A parasitology survey on fish groupers was conducted from January to April in 2016 in a Parasitology Laboratory belongs to Fish Quarantine and Inspection Agency, Makassar, to identify parasites from the fish groups. Previous data available at the institute did not distinguish between species of fish examined and the parasites that infect them, most of the fish from different species were only categorized as groupers, while many species of parasites are known to have high host specificity. Fifty-four grouper fish of different species were examined, includes; Cephalopholis sonnerati, C. argus, Plectropomus oligocanthus, P. leopardus, P. areolatus, P. maculatus. The fish species are common groupers that are exported alive to various countries. The fish were sent by exporter companies to the laboratory for disease inspection. The fish species were identified, length and weight were measured, then the whole body surface was visually examined for the presence of large parasites. Operculum was cut, and each gills were removed and placed on a petri dish contained saltwater. Observation of parasites presence was conducted under a stereomicroscope, and identification of parasite to genus level was conducted directly under a compound microscope. Species of parasites found were monogenean; Diplectanum sp., Pseudorhabdosynochus sp., Echinoplectanum leopardi, Echinoplectanum sp., Protozoa; Brooklynella hostilis., Cryptocaryon irritans., Crustacea; Hatschekia sp., Dissonus sp., copepod larvae. Diplectanum sp. was found from P. areolatus and C. sonnerati. The prevalence and mean intensity of the parasite in P. areolatus was 100% and 52.5, respectively, whereas the prevalence and mean intensity of the parasite in C. sonnerati was 50% and 69.6, respectively. Pseudorhabdosynochus sp. was only recorded from Cephalopholis spp. Echinoplectanum leopardi only occurred in P. leopardus. Echinoplectanum sp. was also recorded from P. oligocanthus, P. maculatus and C. sonnerati. Other species of parasites commonly found in the fish examined were B. hostilis., C. irritans, Hatschekia sp. and Dissonus sp. All the parasites are highly pathogenic and may complete their life cycle within a container. Therefore, their occurrence in aquaculture facilities may cause significant damage leading to mortality on fish without proper treatment.