Growth and reproductive biology of Capoeta damascina (Valenciennes, ۱۸۴۲) 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 ۱۴۷ specimens of both sexes were sampled monthly from November ۲۰۰۸ to October ۲۰۰۹. The overall sex ratio was female biased. Males were aged ۰-۴ years and females ۰-۵ years. The von Bertalanffy growth parameters were estimated as Linf=۳۴.۸۱ cm, k=۰.۲۷ year-۱, t۰=-۰.۶۵ for males plus unsexed samples, Linf =۴۶.۲۹ cm, k=۰.۲۲ year-۱, t۰ =-۰.۵۹ for females plus unsexed samples and Linf =۶۷.۵۲ cm, k=۰.۱۲ year-۱, t۰=-۰.۷۹ for whole samples. The length- weight relationships were W=۰.۰۲۱L۲.۸۱۵ for males, W=۰.۰۲۲L۲.۸۲۴ for females and W=۰.۰۲۰L۲.۸۳۶ 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 ۵۰% maturity was estimated as ۱۲.۳۵ cm for males and ۱۵.۱۴ cm for females. Fecundity ranged from ۱۵۵۱ (۲ years old) to ۲۰۵۲۳ (۵ 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.