changes in total calcium of persian sturgeon, acipenser persicus follicles during different stages of germinal vesicle migration

the changes of total calcium content of persian sturgeon, acipenser persicus follicles were investigated during different stages of germinal vesicle migration. total calcium content increased during maturation and ripening of the oocytes i.e. migration of nucleus toward the animal pole. according to data, the total calcium of follicles with polarization index (pi: the ratio of the distance of the germinal vesicle from the animal pole over the animal-vegetal oocyte diameter×100) less than 5.2 (group i) were significantly higher than those in groups with 5.7< pi< 8.1 (group ii) and pi> 9.4 (group iii). also, there were no significant differences observed in total calcium content of follicles with pi> 9.4 (group iii) and follicles retained for 20 days in body cavity with pi> 10.5 (group iv). as well, there was a significant negative relationship observed between pi values and total calcium content of follicles. it is concluded that calcium is accumulated during the final oocyte maturation in persian sturgeon.