High validity sex determination of three years old cultured beluga sturgeon (Huso huso) using ultrasonography

Summary The objective of this study was to test existing ultrasound technology for use in early sex identification in beluga sturgeon (3-years-old fish) while including some methodological adjustments. Eighty cultured Beluga sturgeons aged 3 years underwent ultrasonographic examination using a high frequency transducer for sex determination. Sexing of the sturgeons was based on the shape and echogenicity (brightness) of the gonad and surrounding fat tissue in sonographic scans. Accuracy of ultrasound sex determinations were confirmed through directly inspecting the gonads by a small incision in the right or left ventral body wall. Females were identified with 96.7% accuracy (n = 31) and males with 97.9% accuracy (n = 49). Overall accuracy of sex determination using ultrasonography was 97.5%. Using high frequency transducer and transverse scanning just over the swim bladder in 3-year-old beluga may have been contributed in high accuracy sex detection. These technically improvements may be considered an advantage for beluga culture because this fish matures extremely late compared to other sturgeon species.