Age, growth and reproduction of Paracobitis malapterura (Teleostei: Nemacheilidae) from Qom River, Iran

We examined 271 specimens of Paracobitis malapterura throughout the spawning season (February to July, 2014) from Qom River (Central Iran) to describe their age, growth, and reproduction. Sex ratio was 1:6.1 in favor of females. Among the examined specimens, the maximum age was 3 years. The specimens ranged 35-120mm in total length and 0.38-9.58g in total weight. Length-weight relationship was estimated as W=1E-05TL2.94, W=2E-05TL2.73, and W=1E-05TL2.92 for females, males and combined sexes, respectively. The growth type was isometric for females and sexes combined and negative allometric for males. Based on the gonado-somatic index values, spawning occurs between late February and late April. The highest mean GSI was 1.9, and 13.85 for males and females, respectively in April. The absolute fecundity ranged from 164 to 793 with a mean of 353.3 eggs. Fecundity was positively correlated with fish size (length and weight).