The aim of this study to determine the seasonal distribution of helminthes of bream fish (Abramis brama L. 1758) fauna in Terkos Lake from September 2009 to August 2010. During the study examined 161 fish rudd, Dactylogyrus sphyrna and Dactylogyrus distinguendus from Monogenia, Diplostomum spathaceum metacerceria from Digenia, Ligula intestinalis plerocercoid from Cestoda and Piscicola geometra from Hirudinea were parasited. 87% with 124 fish recorded the highest infection D. sphyrna summer, D. distinguendus autumn with 80 fish recorded the highes infection 58%, D. spathaceum metacerceria autumn with 138 fish recorded the highes infection 94%, 34% L. intestinalis plerocercoid in infection with 38 fish recorded the highest recorded in the spring and P. geometra 13 fish the spread of infection showed the highest with 14% in spring seasons.

 Özet: Bu çalışma Eylül 2009 - Ağustos 2010 tarihleri arasında Terkos Gölü'nde yaşayan çapak balıkları (Abramis brama L. 1758)'ndaki helmint faunasının mevsimsel olarak dağılımını araştırmak için yapılmıştır. Çalışma süresince incelenen 161 (♀:73, ♂:88) çapak balığının Monogenia'dan Dactylogyrus sphyrna ve Dactylogyrus distinguendus, Digenia'dan Diplostomum spathaceum metaserkeri, Cestoda'dan, Ligula intestinalis plerocercoidi, ve Hirudinea'dan  Piscicola geometra ile enfeste olduğu saptanmıştır. 124 balıkta D. sphyrna kaydedilerek yazın en yüksek enfestasyon (%87) gösterdiği görülmüştür. Bunu sırayla D. distinguendus (80 balıkta %58 enfestasyon sonbahar), D. spathaceum metaserkeri (138 balıkta %94 sonbahar),  L. intestinalis plerocercoidi (38 balıkta %34 ilkbahar) ve P. geometra (13 balıkta %14 ilkbahar) izlemiştir. Anahtar Sözcükler: Terkos Gölü, Çapak balığı, Helmint, Parazit, Fauna. The Seasonal Distribution of Bream Fish (Abramis brama L. 1758) Helminthes Parasites Living in Terkos Lake (Istanbul-Turkey)   ABSTRACT : The aim of this study was to determine the seasonal distribution of helminthes of bream fish (Abramis brama L. 1758) fauna in Terkos Lake between September 2009 and August 2010. During the study examined 161 (♀:73, ♂:88) fish rudd, Dactylogyrus sphyrna and Dactylogyrus distinguendus from Monogenia, Diplostomum spathaceum metacerceria from Digenia, Ligula intestinalis plerocercoid from Cestoda and Piscicola geometra from Hirudinea were enfested. 87% with 124 fish recorded the highest enfestation D. sphyrna summer, D. distinguendus autumn with 80 fish recorded the highes enfestation 58%, D. spathaceum metacerceria autumn with 138 fish recorded the high enfestation 94%, 34% L. intestinalis plerocercoid in enfestation with 38 fish recorded the highest level recorded in the spring and P. geometra 13 fish the spread of enfestation showed the highest level with 14% in spring seasons Key words: Terkos Lake, Bream, Helminthes, Parasite, Fauna.