Several growth characteristics of an invasive cyprinid fish (Carassius gibelio Bloch, 1782).
Age composition, length-weight relationships, growth, and condition factors of the gibel carp (Carassius gibelio Bloch, 1782) were determined using specimens collected from Seyitler Reservoir between July 2005 to June 2006. A total of 149 gibel carp were observed and examined. The age composition of the samples ranged between I and VII years of age. It has been determined than 82.55% of the obtained samples are comprised of females, 16.11% is comprised of males and 1.34% is comprised of immature. The population is dominated by females able to reproduce gynogenetically. The mean fork lengths and mean weights of the population were 14.8-32.5 cm and 43.1-807.3 g respectively. The length-weight relation were calculated as W=0.0696 L2.132, r=0.838 for females, for males W=0.2942 L2.6417 r=0.784 and W=0.0274 L2.9382, r=0.813 for all samples. The mean Fulton Condition Factor was calculated as 2.342 for females, 2.064 for males and 2.276 for all samples. Age-length and age-weight relations were determined according to von Bertalanffy growth equation formula. Growth parameters of the population were Lt=48.09 [1-e-0.093(t+0.29)], and Wt=2323.62 [1-e-0.093(t+0.29)]2.9382. The growth performance index value (Ø′) was computed as 5.37 for all specimens.