Ocak ve May›s 2000 tarihleri aras›nda yürütülen bu araflt›rmada, dikence bal›klar› (Gasterosteus aculeatus L., 1758) üzerinde Gyrodactylus arcuatus Bychowsky, 1933 türünün varl›¤› tespit edildi. Toplam olarak 151 adet bal›k incelendi. Ortalama enfestasyon oran› ve yo¤unlu¤u, s›ras›yla % 80,2 ve 35,44 ± 8,87 parazit / enfekte bal›k olarak belirlendi. Enfestasyon oran› (%) ve intensitesi s›ras›yla fiubat ve May›s aylar›nda en yüksek de¤erlerinde kaydedildi. ‹statistiki olarak, bal›¤›n cinsiyetine göre bir enfestasyon tercihi belirlenmedi. G. arcuatus’un enfestasyon intensitesi en fazla solungaçlar, ard›ndan da yüzgeçler ve vücut yüzeyinde kaydedildi. Boy s›n›flar› dikkate al›nd›¤›nda, G. arcuatus’un bal›¤›n vücut k›s›mlar›ndaki yay›l›fllar›nda önemli farkl›l›klar belirlendi.

Gyrodactylus arcuatus Bychowsky, 1933 was identified on the three-spined stickleback, Gasterosteus aculeatus L., 1758 in the present study, which was carried out between January and May 2000. A total of 151 fish specimens were examined. The infestation prevalence and mean intensity levels were 80.2% and 35.44 ± 8.87 parasites per fish, respectively. The infestation prevalence and mean intensity levels were highest in February and May, respectively. No statistically significant preference for either sex of fish was determined. The mean intensity of G. arcuatus was highest on the gills, followed by the fins and skin. Significant differences were observed in the distribution of G. arcuatus over the body parts studied with respect to the length classes of fish.