Determination of growth parameters, Age structure and sex ratio in Broodstock of Roach Rutilus caspicus (Yakovlev, 1870) in the southeastern coast of the Caspian Sea (Golestan Province)

The aim of this study was to record growth parameters, age structure and sex ratio of Broodstock of roach (Rutilus caspicus) from East coast of the Caspian Sea. For this purpose, 290 samples were caught by trap (26 mm mesh size) during February 2015 to May 2015. The age rang were 1 to 4 years for male and female among which 59.45% of age composition was belonging to year classes of 2 and 35.75% of age composition was belonging to year classes of 3. Female to male sex ratio was obtained 1:1.61 which was a significant diference (p= 0/000). Fork length (FL) and weight (W) ranged from 125 to 214.79 and 135 to 270 mm and 29.03 to 188.3 and 43.67 to 293 g for male and female, respectively. The b value of using FL was calculated as 3.039 and 3.197, respectively, and the growth pattern was isometric in the male fish (p>0.05) and positive allometic in the female fish(p