Gonad Histology of One-year and Two-year old Cultured Beluga (Huso huso) from Qom Province

As the most of the efforts for sex determination of the sturgeon fishes have focused on the 3 years old and older specimens, it seems that the sex determination is not practically possible in the younger sturgeons. In this study we have examined 12 one-year old and 12 two-year old cultured Huso huso (Acipenseriformes) gonads from Qom province aquaculture site to check the possibility of sex determination. Histology and H&E staining were performed and light microscope was used for sex determination and gonad staging. 25% of one-year old fishes were male and 41.66% were female and the gender of 33.33% of them was unknown. Among 2 year-old fishes, the percentage of sexes, for both males and females was equal to 41.66% and the sex of 16.6% of them was unclear. One-year old females have oogonia and primary oocytes and their gonad stage was suggested as stage (I). In the Two-year old females, oogonia, primary and secondary oocytes were observed and their gonad stage was suggested as (I - II). Gonad stage of both one-year old and two-year old males was determined as stage (I). Our results show that histology and light-microscopic observation can be used to sex determination of two-year old and one-year old belugas.