A new method to determine sex and gonad size in live fishes by using ultrasonography

• Published in: Journal of Fish Biology
• Main Author: Mattson, N. S.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1991
• Subjects: Atlantic salmon; Salmo salar
• Online Access: http://dx.doi.org/10.1111/j.1095-8649.1991.tb04397.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1095-8649.1991.tb04397.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1095-8649.1991.tb04397.x

A method to determine, non‐invasively, sex and gonad size employing ultrasonography and using Atlantic salmon, Salmo salar Linnaeus, as an example, is described. Although gonads of immature males may be difficult to discern, gonads of females are always visible and hence sexing is possible by deduction. Gonad diameter can be estimated by ultrasonography; the correlation coefficients between ultrasonographic and ruler‐derived measurements were 0.926 for females and 0.754 for males. The appearance of ultrasonographic images of the gonads during sexual maturation are described. The results are discussed and suggestions made to improve the quality of images and reliability of measurements.