University of Guilan Aquatic Physiology and Biotechnology 2345-3966 7 2 2019 09 07 Determination of sex and relationship with morphometric parameters in 18-months old cultured beluga sturgeon (Huso huso) using ultrasonography and small surgery Determination of sex and relationship with morphometric parameters in 18-months old cultured beluga sturgeon (Huso huso) using ultrasonography and small surgery 31 48 3480 10.22124/japb.2019.10906.1262 FA Raheleh Esmailnia Ph.D. Student in Aquaculture, Tonekabon Branch, Islamic Azad University, Tonekabon, Iran Mohammad Reza Ghomi Associate Professor in Department of Fisheries, Tonekabon Branch, Islamic Azad University, Tonekabon, Iran Mehdi Sohrabnezhad Ph.D. in Aquaculture, Saee Sturgeon Aquaculture CO., Sari, Iran Journal Article 2018 07 22 The aim of this study was to determine the early sex of 21 pieces of 18-month-old farmed fish using ultrasonography as a new method of sex determination and small surgery. For this purpose, a linear array transducer ultrasonography with the frequency of 9-13 MHz was used. The overall accuracy of sex determination using ultrasonography (7 males, 10 females and 4 not correct determined) and small surgery (9 males and 12 females) were 80.95% and 100%, respectively. There was no correlated to morphometric parameters including TL, SL, W and CF in 18 months beluga sturgeon with sex (P>0.05). Although a small surgical procedure is an invasive procedure, it is the safest method and no casualties have been reported. Fish morphometric parameters including TL, SL, W and CF related to sex determination by both methods using logistic regression test showed no significant relationship with fish sex (P<0.05), then cannot be used as an indicator of sex determination at this age. The aim of this study was to determine the early sex of 21 pieces of 18-month-old farmed fish using ultrasonography as a new method of sex determination and small surgery. For this purpose, a linear array transducer ultrasonography with the frequency of 9-13 MHz was used. The overall accuracy of sex determination using ultrasonography (7 males, 10 females and 4 not correct determined) and small surgery (9 males and 12 females) were 80.95% and 100%, respectively. There was no correlated to morphometric parameters including TL, SL, W and CF in 18 months beluga sturgeon with sex (P>0.05). Although a small surgical procedure is an invasive procedure, it is the safest method and no casualties have been reported. Fish morphometric parameters including TL, SL, W and CF related to sex determination by both methods using logistic regression test showed no significant relationship with fish sex (P<0.05), then cannot be used as an indicator of sex determination at this age. https://japb.guilan.ac.ir/article_3480_e3174b9e4db83ed57b3e2ea9977b4c78.pdf