Ultrasound evidence of fetal resorption in the yellow stingray, Urobatis jamaicensis (Urotrygonidae)
Ultrasound technology was used to document fetal resorption in three pregnant yellow stingrays, Urobatis jamaicensis (Cuvier, 1817), at the John G. Shedd Aquarium, Chicago, IL, USA. Copulation for the three focal females in this study occurred from 30 April 2010 through 16 May 2010. Ultrasounds were performed monthly until females were confirmed pregnant and during the last three months of gestation. Mothers were confirmed pregnant on both their second and four-month ultrasounds. On their five-month ultrasounds there was evidence of fetal tissues within their uteri but respiratory rates were not detected. Six-month ultrasounds confirmed the complete absence of fetal tissues in the uterine horns of all three previously pregnant females. To our knowledge this is the first documented case of fetal resorption in U. jamaicensis.