A Smooth back river stingray (Potamotrygon orbignyi) pup was born on January 16, 2010.
Stingrays reproduce by aplacental viviparity which means that the eggs hatch and the babies develop inside the female’s body but there is no placenta to nourish the pups. Embryos initially feed on yolk, then receive additional nourishment by absorbing “uterine milk” from their mother. The young are born as miniature adults, free-swimming and ready to feed on their own.
The main consideration in caring for the newborn pup will be making sure it gets enough to eat. Newborn pups are not strong swimmers and may not be able to compete for food with all of the adult rays. Pancake has been doing wonderfully, though, and has already had his first couple of meals of tubifex and bloodworms.