Application of ultrasound in determination gestation status in captive female freshwater stingray (potamotrygon sp.)

摘要

Freshwater stingray is one of the popular ornamental fish trade in Thailand. Early pregnancy diagnosis could improve reproductive performance and management in captive breeding. Therefore, the main objective of this study was to apply and develop techniques for determination of gestation status in freshwater stingray by using ultrasonography. The stingrays were placed in a fitted tank with water in ventral recumbency position. The imaging was done in B-mode. The suitable frequency was 6.5 MHz, covered all size of pregnant female stingrays. However, the frequency may be converted to 5 MHz or 8 MHz to identify implanted embryo or trophonemata. The scanning showed 3 stages of gestation; first stage, mid stage and final stage with different characteristic. The present study suggested that this application, a noninvasive technique, can be continuously used for determination the gestation status from 4-12 weeks of gestational age in captive female stingray.