Life history pattern of an Eurasian Cyprinid, Rhodeus amarus, in a large drinking-water system (Ömerli Dam Lake-Istanbul, Turkey)
Ali Serhan Tarkan, Özcan Gaygusuz, Çigdem Gürsoy, Hasan Acipinar
Istanbul University, Faculty of Fisheries, Ordu Cad. No: 200, 34470 Laleli, Istanbul, TURKEY
Çanakkale Onsekiz Mart University, Natural and Applied Sciences Institute, 17100, Çanakkale, TURKEY
Istanbul University, Natural and Applied Sciences Institute, 34850, Istanbul, TURKEY
The life history pattern (age, growth and reproduction) of bitterling, Rhodeus amarus (Bloch, 1782), was studied in the Ömerli Dam Lake a large drinking water system located in Istanbul (Turkey) between April 2003 to August 2004. Age determination based on opercula readings and validated by scale readings and length frequency analysis shows that population has a 5-year life cycle. The von Bertalanffy growth function was fitted to length-at-age data and displayed variation in growth rates between sexes. Total length-weight relationship was estimated as W = 0.0077TL3.29 for males and W = 0.022TL2.73 for females. Spawning season was from April to August. The ratio of males to females was 1:2.32. Condition of male increased from August until April while condition of females fluctuated throughout the year.
Keywords: Rhodeus amarus, age, growth, life history, Ömerli Dam Lake