DANA POINT Tom Southern, an avid waterman, couldn’t believe it when he saw five devil rays gliding at the surface of a glassy sea two miles out of the harbor.
“They were just swimming around in circles feeding at the surface,” said Southern, a boat captain for Capt. Dave’s Dolphin and whale Watch Safari. “I’ve been out in the water all my life and I’ve seen bat rays, cow-nosed rays and spotted eagle rays but I’ve never seen these. They’re much bigger.”
Spinetail Mobula also known as Devil rays
What they look like: Large ray with a whip-like tail with a sting at the tip.
Mouth: Teeth in both jaws.
Upperside of body: Dark blue or black with slits and a white area behind eyes.
Underside: White with two fins.
Size: Can have width of up to 10 feet.
Diet: Plankton, krill and small fish
Habitat: Warm waters in the Pacific and Atlantic oceans.
Classified: Near threatened because of low reproduction and fishing.
What they are: They are a close relative of all sharks and rays. The fact that they are fish means they don’t breathe air, but instead they use their gills to respire underwater. Mantas must keep moving in order to keep water flowing over their gills, which means they can never stop to sleep or rest on the seabed.
Source: Manta Trust
Josh Stewart from Scripps Ocean Institute, an expert on the sea creatures, said the sighting of devil rays near Dana Point is rare. He is the associate director of the Manta Trust, a group focused on studying and protecting manta and mobula rays – often called devil rays.
There are nine species of mobulas, two species of mantas. All vary in maximum size, ranging from 1 meter in disc width (wingspan) for the smallest mobula rays, to over 7 meters in disc width for the largest oceanic manta rays.
“Devil rays generally live in tropical and subtropical waters, so seeing them in the cold waters of the California current is indeed rare,” he said
Some are sometimes found caught in gill nets. They are also commercially fished in some countries and are often targeted for their gill rakers, which are used in a pseudo-remedy in Traditional Chinese Medicine, Stewart said. These are dried and shipped to China, where demand is driving targeted fisheries for mantas and mobulas around the world. Due to extremely low population growth rates, any targeted fishing pressure has dramatic effects on populations.
The rays are also cousins to sharks. They are both elasmobranchs—cartilaginous fishes. Mobulas and manta rays are related to sharks in this way but have dramatically different feeding mechanisms. All mobulids are filter feeders, feeding on small zooplankton and occasionally small fishes, which they essentially strain out of the water.
Research shows that mantas probably live to at least 50 and possibly up to 100 years. Still scientists say they need at least another 20 years of data to know for sure. Ping-Pong, a Maldivian reef manta, was first photographed by divers in 1989 when she was already fully grown and sexually mature. Ping-Pong is still seen now at the same site almost every year. It’s thought that mantas are 15-20 years old when they reach sexual maturity, which would make Ping-Pong at least 40 years old.
In California, Stewart said, it would be unlikely to spot them surfing or on a SUP, but you are very likely to see the California bat ray, which is a distant cousin to the mobulids but much more closely related than sharks.
Devil rays are not dangerous to humans, but they have spines or barbs on their tails for defense against predators, Stewart said. They do not swim at the bottom of the sea, but more often near the surface where zooplankton is plentiful
“They’re extremely hard to find and study, which means we know very little about them,” he added. “I’d say this general lack of information on a marine megafauna is very unusual and makes them somewhat mysterious.”
Southern said he followed the rays for about 15 minutes. They didn’t like swimming beneath the boat or in front of it but just kept fluttering along the surface at the boat’s side. Passengers on board were amazed to see creatures known to be so rare.
“They were mysterious visitors that even researchers don’t know much about,” Southern said.