Some biological aspects of Acipenser persicus, Borobin 1897, in the southern Caspian Sea

This study has been carried out in Mazandaran waters in the southern Caspian Sea from 2009 to 2012. Sampling of this fish only for conservation and restoration of sturgeon based on CITES for artificial propagation. Number of 273 individual was recorded. Totally، 6773 kg of A. persicus caught that 723. 75 kg caviar was obtained. The highest frequency (56. 4%) recorded in 2010 and the minimum frequency (13. 2%) was found in 2009. The results shown that the minimum and maximum fork length was ranged 63-224 with average 151. 2±19. 4 cm and body weight was 3-132 with mean 24. 8±10. 6 kg respectively. Sex ratio of male to female (1:1. 9) was found. Mature females were in stage IV at sex maturity. Based on caviar brand of A. persicus comprised to grain one (46%)، grain two (9. 2%)، grain three (3%) and press caviar (3. 7%) were found. Overall، based on multivariate analysis the results show that the highest similarity in March-April could be due to close to spawning season (86%)، November- December close to Feeding period (98. 3%) and February-March close to Wintering (79. 6%).