.Isolation of caligus parasite from cobia (Rachycentron canadum) and how to remove it.

Sea lice caused serious harm to cultured marine finfish in the world. 54% of copepod infestations in marine fishes associated with outbreaks of sea lice. This parasite caused skin lesions near the head, and high infection can result in fish death. Eleven wild cobia with weight ranging from 0.5 to 3.4 kg were collected from the Persian Gulf and transferred to quarantined tanks at Persian Gulf Mollusks Research Station. The fish were examined for any existence of external parasites by the naked eye. And, caligus were found in nine cobia. The highest caligus density was recorded on the head. Furthermore, this parasite was found on the body surface, operculum, fins (dorsal, pelvic, and pectoral). The maximum and minimum caligus densities were 156 and 41, respectively. Trichlorfon (1 ppm for 60 min) or freshwater (0.5 min) were applied by the bath to kill sea lice. In both methods, the fish tanks were changed.