The sea commom carp Brood stocking (Cyprinus carpio) in pen culture in Gorgan bay

This study was conducted to investigate the possibility of breeding carp juveniles (Cyprinus carpio) in pen conditions in Gorgan Bay in two treatments with a density of 2 and 4 pieces per square meter in order to produce breeders for restocking centers. The first juveniles were raised in earthen ponds with concentrate feed. Then, with an average weight of 93.87± 32.66g, they were transferred to pens with an area of 50 m2each and 16 mm mesh size, in Gorgan Bay. 6 pens were considered for this research and for each treatment, 100 and 200 pieces of juveniles were considered in each pen. Feeding was done with concentrate feed and physical and chemical factors and biometry of fish were done regularly. The results showed 52% survival in first treatment and 49% for second treatment and the mean weight for two treatments were 410± 64.98 and 390±52.8. Results showed that there was no significant differences between weight and length in two treatments. The histological results showed that the male and female were mature in 4th stage. The eggs of the female fish were between 800 and 1200 microns in diameter.