It’s not unusual to see a Thorntail Stingray lying at the bed of the ocean or in this case the Open Ocean Exhibit at uShaka Marine World in Durban, but what is unusual was her growing belly that caught the attention of the South African Association for Marine Biological Research (SAAMBR) veterinarians.
Dr Francois Lampen joined his colleagues Dr Justin Hart and Dr Ryan Daly in the Open Ocean Exhibit armed with an underwater ultrasound machine. It was the first time that they have been able to carry out an ultrasound on any of the fish, sharks and rays whilst they went about their day in their exhibit, oblivious to the fact that a medical examination was taking place, said Dr Lampen.
“We knew that one of the Thorntail Stingrays was pregnant as we could see her bump, but we were unsure exactly how far along she was. As she generally spends a fair amount of time resting on the bottom of the exhibit as rays do, we were confident that we would be able to hover over her long enough to capture video and images of her embryos,” said Dr Lampen.
“Even though we were confident she was pregnant, when we actually saw three healthy embryos wriggling around on the ultrasound monitor, we could hardly contain our excitement.”
The Thorntail Stingray gave birth to six pups in her last litter, added Dr Lampen. He said they anticipate that with refining the technique they will likely see more pups on the ultrasound. The smallest litter size they have had before was four pups, said the aquarium curator, Dr Hart.
“By using this novel method of monitoring the gestation period over multiple pregnancies, we will be able to get a better understanding of their embryonic development. This method is non-invasive and doesn’t require sedation which means we can monitor them on a frequent basis,” said Dr Hart.
“Going forward, we will hopefully be able to use this technique to monitor the organs of other animals in our care without having to either sedate or restrain them in any way.”
SAAMBR said they will give an update on stingray’s pups once they are born.
