Early sex identification of 18-month cultured beluga sturgeon (Huso huso) using ultrasonography, small surgery and plasma steroid hormones

Abstract

Since sturgeons do not show clear sexual dimorphism particularly when are small in size, attempts were made to determine the best methods to identify early sex in farmed beluga sturgeon (Huso huso). The present study describes the ultrasonography, small surgery and plasma steroid hormone methods to determine gender at 18-month fish, which no research has been conducted yet into the fish at such small ages. Twenty one cultured beluga sturgeon's gonad were imaged using an ultrasonograph unit with a 9–13 MHz linear transducer. Overall accuracy of sex determination using ultrasonography was 80.95%. Plasma testosterone (T) levels were significantly higher in males than in females whereas 17α,20βOH-P levels were significantly higher in females than in males. Testosterone (T) and 17α,20βOH-P were not correlated with morphometric parameters (TL, SL, W, CF) in 18-month beluga sturgeon. Results of this study indicated that sex could be identified by each of ultrasonography, small surgery and analysis of blood plasma in such a small size (18-month). Although direct observation was more efficient than the other methods, ultrasonography was the simplest and cost-effective tool in sturgeon's sex determination compared to other methods, and the least invasive.