Morphology And Life Cycle Of Crustacean Parasite, Lernanthropus Sp From Cultured Seabass, Lates Calcarifer

Abstract

Parasitic crustaceans of Lernanthropus latis were isolated from the host, Lates

calcarifer, obtained from a cage culture in Setiu Wetland, Terengganu. The morphology of the parasite was described with the aid of Scanning Electron Microscope (SEM). A study of life cycle of L. latis were also implemented under laboratory condition in which description for each larval developmental stage was conducted with the aid of illustration and SEM. Adult females of L. latis with eggs were kept alive in vials containing 20mL of filtered seawater within 27ppt of salinity and incubated at 30 o C. The eggs were monitored every hour and the hatching periods were recorded. Three developmental stages were observed, namely, nauplii I, nauplii II, and infective copepodid. The infective copepodids were then transferred into a tank containing 60L of seawater with 150 seabass fingerlings for infection purpose. One fish was sacrificed every 24 hour to inspect the next developmental stage. As a result, six more stages were obtained within 298 hrs starting from the first day of infection. The stages were known as fixed copepodid I, II, III and IV, preadult, and adult. Parasitic L. latis takes 483 hrs period to complete a life cycle at o 30 C of temperature and 27ppt of salinity.