Age, growth, sex ratio, spawning season and fecundity of Capoeta razii from Sefidroud River in the southern Caspian Sea basin

Abstract

Some aspects of reproductive biology of Capoeta razii , an endemic cyprinid species from the Sefid River in the southern Caspian Sea basin, were studied by monthly sampling throughout a year. Age, growth, sex ratio, spawning season, fecundity, gonado-somatic, modified gonado-somatic and Dobriyal indices were estimated. The sex ratio (F: M) was obtained as 1.00:2.63, and the percentage of males was greater than females. The mature males and females were longer than 88 and 148 mm in total length, and 1 + and 2 + in age, respectively. The spawning of C. razii took place from late May to late August when the water temperature was between 19.7 and 22.8 ◦ C. At the beginning of the reproduction period, the average gonado-somatic index values were 10.0% ranging from 4.03% to 15.90% in ripe females. The estimated gonadal indices showed that the ripe males were ready to spawn earlier than females. The average egg diameter was 0.99±0.65, ranging from 0.2 to 2.3 mm. The averages absolute and relative fecundity were 4386±2174 and 66.3±37.8, respectively. The absolute fecundity was significantly related to body weight and gonad weight.