Nine newborn thorntail rays (Dasyatis thetidis) were found swimming in the Open Ocean Exhibit at uShaka Marine World, after being born on 17 and 28 December 2014.
Photo: uShaka Sea World staffer, Matt Needham with a ray pup prior to release
Story by Ann Kunz
As staff conducted their regular early-morning exhibit inspections, the first batch of ray pups was spotted swimming around near the floor of the exhibit.
The babies, born on 17 December, were left in the exhibit while staff waited for a second pregnant female to give birth. She did so 11 days later, bringing the baby total to nine.
Newborn pups are almost identical miniature replicas of their parents and independent from birth. They are capable of surviving without food for several days before needing to catch prey.
vehicle for release at uShaka beach
Avoiding predation is their primary focus after birth, as they are the favourite food of many ocean predators, particularly sharks. It was decided to release all the baby rays into the ocean, as uShaka Sea World already has a number of juvenile and adult rays in the Open Ocean Exhibit.
uShaka Sea World divers caught and gently lifted the pups from the exhibit using hoop bags, before transferring them to a specially equipped transport tank mounted on a two-ton trailer.
They were first taken to the quarantine facility for weighing, measuring and an overall health check before being taken to the beach in front of uShaka for release.
Interestingly, the same two mothers gave birth to a total of 10 baby rays at the same time last year.
Thorntail rays are one of the largest ray species found along the KwaZulu-Natal coast, living inshore and offshore at depths of up to 400m. On occasion, rays are accidently caught by shore anglers.