Morphological analysis for non-invasive sex determination in ‎beluga (Huso huso)‎

Beluga (Huso huso) is one of the most important commercial fish in the Caspian Sea, whose reproduction and breeding, as well as caviar extraction, are of special importance. This study was conducted to investigate the morphological analysis for non-invasive sex determination in this sturgeon species to replace the invasive methods in the event of appropriate outcomes. A total of 180 fish were biometried at the Sea Abzigostaran Center, Sari, within 2 weeks. The samples were then photographed and the photos were analyzed by the TPS (transection processing system) technique for sex determination. The ANOVA test showed homogeneity of morphormetric data. Leven's test showed that all the morphometric traits had uniform variances (P ≥ 0.05). The analysis of the distinctive function for morphometric traits indicated that 100% of both male and female beluga samples displayed their characteristics. Overall, the results of this test revealed that on average 100% of the males and females were grouped accurately, which indicates the separation of the sexes based on this test. The UPGMA dendrogram for morphological traits based on the mean correlation showed that the samples of beluga were partially distinguished from each other by gender. However, the TPS technique could distinguish the male and female beluga samples, thus, it could be considered a non-invasive method for the sex determination of sturgeon fish.