Comparative analysis of reproductive performance between spring and autumn forms of Persian sturgeon, Acipenser persicus, Bordin, 1897: with an emphasis on sex steroids and milt quality

摘要

To compare the reproductive performance of spring and autumn forms of Persian sturgeon males, Acipenser persicus, the relative abundance of spermiating and non-spermiating males, milt quality, sex steroids and cortisol were investigated after pituitary preparation (PP) treatment and at the time of spermiation. Our results showed that higher numbers of spring males are spermiated after PP treatment than autumn individuals. The autumn spermiating males had higher and lower values of sperm density and duration of motility than spring males respectively. The milt volume was higher in spring males than in autumn individuals. The percentage of motility was statistically equal in both the groups examined. In both forms of brooders, the serum levels of testosterone (T), 11-ketotestosterone (11-KT), progesterone (P), 17, 20β, 21-trihydroxy-4-pregnen-3-one (20βS) and cortisol (C) increased after PP treatment, although such increases did not occur in non-spermiating males. Our results showed the probable involvement of 20βs, P, T, 11-KT and C in the final maturation of Persian sturgeon. In addition, it was demonstrated that the spring form of Persian sturgeon shows better reproductive performance than the autumn form in terms of a response to artificial induction and milt quality.