Laparoscopy, a minimally-invasive technique for sex identification in cultured great sturgeon Huso huso

Laparoscopy is a fast, effective, and minimally invasive method for determining the sex and reproductive stage of great sturgeon (Huso huso) via a small (1 cm) incision in the abdominal wall. The system consists of a 7.5 mm, 22 cm long cystoscope sheath, fiber-optic light, halogen cold light source, video camera with a control unit, and a color monitor, and allows direct viewing of the abdominal organs of a fish. In this study, it was used on 120 farm raised great sturgeon ranging in age from 3 to 16 years. Sex identification was successfully performed in all fish which 95.8% sexed with laparoscopy alone. Five of 120 sturgeon required gonadal biopsy and microscopic examination to confirm sex. The unidentified fish were smaller and thinner than others. Results showed that both sexes could be identified with this system as early as 3 years of age and the sex ratio under culture conditions of females, males and unidentified sex were 56.6, 39.2 and 4.2%, respectively. While most reproductive applications of laparoscopy in great sturgeon related to the visual identification of gender and reproductive stage, the ability to biopsy the gonad enabled these identifications to be objectively assessed using histology. Our results suggest that laparoscopy is an efficient technique for sex identification at different ages and determination of gonadal development stages in great sturgeon. The ability to safely perform minimally invasive reproductive surgery in this species may have important management and conservation benefits during the culture period or wild population assays.

► Cultured immature and mature great sturgeons were examined for sexing via laparoscopy.
► Applying laparoscopy showed that this method is an efficient technique at different ages.
► We found that the ability to safely perform minimally invasive reproductive surgery.
► It could have benefits during the culture period or wild population assays.