Az ultrahangvizsgálat szerepe a szibériai tokhalak ivarmeghatározásában

Abstract

Our aim was to study the ultrasound sex determination and precision of the method in a Siberian sturgeon population. The data collection was carried out at a Hungarian, large fish colony. 30 pieces, 4 years old, 2.0 to 6.3 kg (mean 4.02 kg) body weight of individuals tested. The ultrasound sex determination was performed by two investigators, with different practices. In parallel, the sex of the animals also been determined by trocar which method routinely used to define the specific sex. The effectiveness of the methods was checked post-mortem tissue studies. Processing of the results of the experienced and inexperienced ultrasonic investigators have been compared with the results of trocar method and also compared with each other. Overall, we found that the 30 fish tested with 90% efficiency by the experienced sonographer, and with 80% efficiency by the initial sonographer. The method trocar has given 63% correct diagnosis. Comparing the results of the two ultrasound investigators and the trocar method the following conclusions have been made: the advanced ultrasonographer had statistically greater effectiveness in validly (p = 0.0215) than trocar method. The same comparison in the initial sonographer and trocar was not given significant difference (p = 0.2668). Comparison of two ultrasonic test results was also not a significant difference (p = 0.4531). From the results it is concluded that the ultrasonic pre-qualification was not a decisive difference in effectiveness for the studied sample. The weight of the fish has a greater significance, because only one failed result was given by the ultrasonographic testing of animals among the fish over 4 kg, while the trocar sampling made a mistake in four cases in the same group. The explanation may be that the trocar is a "blind sampling" and may not be able to produce a representative sample in all conditions. In contrast, the ultrasound examination of the gonad can be examined even a long time in multiple planes and this is an opportunity for a more accurate diagnosis, in a non-invasive way. We found that ultrasonography is a highly efficient method in the determination of the sex of Siberian sturgeon. In the case of sexual selection of young fish with small body weight ultrasonography does not make it more efficient, but in 3.5-4 kg body weight clearly increases the efficiency compared to trocar routine.