The present investigation is a survey of endo- and ecto-parasites of the marine fish Amblygaster clupeoides, Gal Hurulla, from Trincomalee.The scope of the survey is to record the types of parasites found in A.clupeoides, to describe their morphology for identification purposes and to analyze the population dynamics of the endo-parasites. Nine different parasitic types, both ecto-parasites, (caligids, copepods'gastropods and isopods) and endo-parasites (mites, trematodes and nematodes) are recorded from this nine-month survey. Morphological features of the parasites are described in detail for identification purposes. Finally, the population patterns of the endo-parasites were analyzed.This survey reveals that the parasites of A. clupeoides are quite diversified. The commonest parasite is Hemiurus Sp. where 1,242 organisms were found. The second most abundant parasite is a trematode parasite belonging to the sub-order Prosostornata. Other parasitic types were observed only in low numbers.
