Age and growth of the Mesopotamian barb, Capoeta damascina, in central Iran

Age and growth of Mesopotamian barb, Capoeta damascina, were studied in the Zayandehrud River, in central Iran, from March 2007 to April 2008. Among the 689 specimens studied, age groups in males ranged from 1+ to 9+ and that in females ranged from 1+ to 10+ . The sex ratio (1M:1.6F) was not significantly different from 1:1 ratio. Maximum fork length and weight was 39 cm and 1,115 g for males and 54.2 cm and 2,340 g for females. In all age classes, females were larger than males. The most frequent age groups were 3+ in males and 4+ in females. The highest value for condition factor was observed in June. The growth of C. damascina was described by von Bertalanffy growth curve as k=0.01, L=56.2 cm, to=-0.63 for males and k = 0.05, L=117.1 cm and to =-0.43 years for females. The length-weigh relationship was described as W=0.0169L2.95 (r 2 =0.98) for males and as W=0.0155L2.99 (r 2 =0.99) for females, indicating an isometric growth pattern in both sexes. Growth performance index was estimated as 5.73 for males and 6.53 for females, indicating a faster growth rate in females