Bu çalışmada, Ocak 1996 ile Kasım 1997 yılları arasında Seyhan Nehiri'nden tutulan 130 adet aynalı sazan (Cyprinus carpio L., 1758)'daki ekto ve endo parazitlerin varlığının belirlenmesine çalışılmıştır. Aylar itibariyle 10'ar örnek incelenmiş, 86 (%66.15) bireyde ağır parazit invazyonu belirlenmiştir. Çalışmamızda, ekto parazit olarak, Monogenean trematodlardan; Dactylogyrus vastator Nybelin, 1924 ve Gyrodactylus elegans Nordmann, 1832, Crustacealardan Argulus foliaceus L., 1758, Protozoan parazitlerden; Ichthyophthirius multifilüs, Fouquet, 1876, ve Trichodina nigra Lom, 1961 bulunurken, Cestodlardan Schistocephalus sp. ve Caryophylaeus sp. endo parazit olarak belirlenmiştir. Anahtar Kelimeler: Sazan, endo-parazit, ekto-parazit, Türkiye. Abstract: The research was carried out in order to determine ecto and endo parasites of 130 mirror carp (Cyprinus carpio, L., 1758) catched from Seyhan River between 1996 and November 1997. During this period each month 10 mirror carps were sampled. 86 (66.15%) carps were heavily infested with the parasites. Ecto parasites such as Monogenean trematods; Dactylogyrns vastator Nybelin, 1924 and Gyrodactylus elegans Nordmann, 1832, Crustacean parasites; Argulus foliaceus L., 1758, Protozoan parasites; Ichthyophthirius multifiliis, Fouquet, 1876, and Trichodina nigra Lom, 1961, Cestodes such as Schistocephalus sp. and Caryophylaeus sp. were also found as endo parasites.

The presence of parasites is, to a large extent, detrimental for a fish population and consequently, imposes high losses fish. Parasitic invasion on fishes may cause high mortality, weight losses and reduced fecundity (Grabda, 1991). Protozoan, Cestoda, Nematoda, Trematoda and Crustacean parasites caused serious diseases on both cultured and wild fish species. These parasitic groups, block fish growth, prevent feeding activity. Especially in waters, contaminated with industrial and urban pollutants, poor water quality and lack of nutrition cause parasitic disease outbreaks. It is one of the most important rivers of the Southern Anatolia and is located in the middle of the Çukurova Savannahs and the Adana city. Although there has not been an extensive fish culture in the river, some fishing activities with fishing lines and nets can be seen in the region (Saraçoğlu, 1990). Some fish farms located at the region have been using the river as their pond water sources. Determining the parasitic species