Growth and reproductive biology of Capoeta damascina (Valenciennes, 1842) from a tributary of Tigris
Growth and reproductive attributes were determined for Capoeta damascina, an endemic fish species from west of Iran. A total of 147 specimens of both sexes were sampled monthly from November 2008 to October 2009. The overall sex ratio was female biased. Males were aged 0-4 years and females 0-5 years. The von Bertalanffy growth parameters were estimated as Linf=34.81 cm, k=0.27 year-1, t0=-0.65 for males plus unsexed samples, Linf =46.29 cm, k=0.22 year-1, t0 =-0.59 for females plus unsexed samples and Linf =67.52 cm, k=0.12 year-1, t0=-0.79 for whole samples. The length- weight relationships were W=0.021L2.815 for males, W=0.022L2.824 for females and W=0.020L2.836 for combined sexes, all of which exhibited a negative allometric growth. Spawning season started in May, ascending to June and ended in July for both sexes. Length at 50% maturity was estimated as 12.35 cm for males and 15.14 cm for females. Fecundity ranged from 1551 (2 years old) to 20523 (5 years old) eggs per fish. Losing of large individuals and decreasing in size at first maturity were observed in the studied population compared to data reported from other C. damascina populations, which could reflect an effect of overexploitation.