Abstract
The present study was conducted to understand changes of seminal fluid sex steroids and milt quality of Russian sturgeon during sequential stripping. Milt samples were collected three times with 24 intervals. According to results, the values of sperm motility duration, sperm production and seminal fluid steroids including 17a-Hydroxyprogesterone (OHP), testosterone (T) and estradiol-17β (E2) decreased significantly during sequential stripping. The levels of OHP showed a close positive correlation with percentage and duration of sperm motility. Similar correlation was found between T and E2 with sperm concentration. The P concentrations did not have significant correlation with sperm quality parameters. Our results revealed that the ability of Russian sturgeon in production of milt with desirable quality decreased with repetition of milt collection. Changes of seminal fluid steroids may be an image of their serum changes during spermiation period. As well as, seminal fluid sex steroids may affect milt quality after spermiation.