Histological study of different layers of Oocyte in Stellate Sturgeon (Acipenser stellatus)

Abstract

The present study was conducted on a large number of oocytes collected from 36 female Acipenser stellatus brood fish caught from fishing grounds in the Guilan province and transferred to the Shahid Behesti Sturgeon Breeding Center during 1997-1998. Physiological assessments were carried out on the microscopic sections prepared from these oocytes. Under normal conditions, 9 distinguishable layers were observed in the sections prepared from A. stellatus oocytes that included the follicle, the outer most layer, followed by a jelly coat, an external zona radiata, internal zona radiata, fat layer, pigments, cytoplasm, nucleus and nucleoli. The presence of erythrocytes and micropyle canal in the oocytes indicate normal embryognesis among them.