We usually think of sharks and rays as egg-layers (you’ve probably seen one of those otherworldly mermaid’s purses), but as beachgoers in Namibia discovered this week, several species give birth to live offspring.
Kolette Grobler, a marine biologist with Namibia’s Ministry of Fisheries and Marine Resources, was on her way to the beach when she received a call from worried animal rescue authorities. Not only had a bluntnose guitarfish* (Acroteriobatus blochii) stranded, but it had also begun to give birth to a brood of small offspring.
“The first call-out occurred midway through my morning kick-start cup of coffee,” she posted on Facebook. “With the interesting topic, ‘Do sandsharks give birth on land or in the water?'”
Contrary to popular belief, the pointy-nosed ocean creatures are not sharks at all, but rather rays. They also don’t spend a lot of time on sandy beaches. The most plausible scenario is that a predator pursued this fish inland.
“Shortly before they found her, the local SPCA [who spotted the ray] reported there was a large seal in the seas nearby,” Grobler added. “By the time I arrived, she had already given birth to roughly five kids, but more were still coming out, each with its yolk sac still attached.” Because of the existence of huge yolk sacs, these infants were delivered early. We would anticipate a fully formed baby ray to emerge with little (or none) of the nutrient-rich yolk remaining since the embryos feed on it.
Despite their ferocious reputations, many elasmobranchs (sharks, skates, and rays) are stress sensitive and have been seen to enter early “labor” after extended conflicts (either on the line or with would-be predators like our lurking seal).
Grobler feared the worst when the puppies began floating upside down and showed no signs of life at first. After repeated attempts by the crew to correct the kids, they began to swim one by one.
“Seven kids were alive and swimming about fairly strongly,” she said, “albeit slightly asymmetrical due to the drag effect of the yolk sac.” “We transported them into deeper, darker water because we were concerned about predators like kelp gulls seeing them from the air.”
Grobler carefully guided the pups toward their mother, who was laying calmly on the seafloor with an eighth youngster on its way out. “We didn’t want to pull it out in case we hurt either the baby or the mother,” she explained. “I examined her spiracles one more time and observed them closing and opening, which told me she was still alive.”
As exciting as this res.cue is, it’s crucial to recognize that these newborns are far from out of dan.ger. Even in a healthy, fully formed brood, only a small percentage of pups will survive to maturity. These infants were estimated to be two to three weeks preterm, which means they were likely matured enough to function on their own – but whether or not they survived remains unknown.
“We don’t know,” Grobler said. “We remained there for a while, watching as a couple of the kids’ pointed ‘noses’ poked out from beneath her flanks. They didn’t try to swim out from under her, as if they knew they’d be secure as long as they kept concealed. We just left them there, praying for the best.”
On that topic, if you find yourself in a similar scenario, your best bet is to notify your local wildlife authority. Even with the greatest intentions, handling stranded marine life can occasionally cause more harm than benefit.
