Metazoan parasites of pike (Esox lucius L.) from Lake Uluabat, Turkey

In this study, metazoan parasites of pike (Esox lucius L.) from Lake Uluaba t were investigated monthly from January 1993 to January 1994. Parasites be longing to six species were recorded for 133 pike hosts: Argulus foliaceus, Tetraonchus monenteron, Rhipidocotyle fennica, Diplodiscus subclavatus, Ra phinascaris acres, and Acanthocephalus anguillae, of which only two specime ns of A. foliaceus were found in the gills of one host fish, and a single s pecimen of A. anguillae and two specimens of D. subclavatus in the intestin e of another. Tetraonchus monenteron, R. fennica, and R. acus were the domi nant parasite species found in the pike. Tetraonchus monenteron was the mos t prevalent species found in fish of all sizes during the year of the study . Rhipidocotyle fennica infection rate was highest during summer and autumn and minimal during winter and early spring, with larger pike having more p arasites than smaller host pike. The third dominant parasite, R. acres, pro duced two generations per season, with peaks in spring (April) and autumn ( October). There was a negative correlation between size of the host and den sity of R. acres. Occurrence, density, seasonal changes, and the preference s of the parasite species for various size groups of its pike host are disc ussed in detail.