Background. Prussian carp, Carassius gibelio (Bloch, 1782), is one of the successful invaders of freshwater systems of Turkey. Although, Prussian carp has rapidly expanded its area of distribution in Anatolia during the last two decades, there is limited information about its biological features in new environments. In order to determine the impact of invasive species on ecosystem, the life history characteristics of an exotic fish species in different locations should be monitored. The presently reported study provides information about the growth and reproduction of Prussian carp introduced into a reservoir in Central Anatolia. Materials and methods. Age, growth, and reproduction of Prussian carp were studied during a 3-year period in Gelingüllü Reservoir, Kızılırmak River Basin. A total of 344 specimens were caught by gill nets. Age was determined from scales. Length–weight relation, von Bertalanffy equation, and specific growth rate were used to evaluate the fish growth. In order to assess growth and reproduction patterns, fecundity, GSI, and variations in oocyte size were determined. Results. Both males and females reached a maximum age of 5+ years. Fork length was 6–27 cm in males and 5.6–26.8 cm in females. Both sexes matured during their second year of life (1+ year). In the Gelingüllü Reservoir population the males were predominant¾the overall sex ratio was 1.39 : 1 (193 males to 139 females) and differed significantly from unity. The von Bertalanffy growth equation was Lt = 32.17 (1 – e–0.232(t – 0.094)) cm for males and Lt = 36.03 (1 – e–0.212(t – 0.205)) cm for females. Growth in length was approximately 70% in males and 85% in females during the first year of life. The somatic condition of the fish increased markedly during late spring and summer. A prolonged spawning period was observed from April to August. Maximum egg diameter was 1.51 mm and maximum absolute fecundity was 174 000 oocytes. Conclusion. Compared to previously published data, the studied Prussian carp population was characterized by more rapid growth during the first year of life, earlier maturity, higher fecundity, and a shorter life span. These life history characteristics are typical of invasive species.

Prussian carp, gibel carp, non-native fish, longevity, growth, fecundity, Anatolia