North Carolinians who were cheering on swimmers during the final stretch of an open-water race off the coast of Wrightsville Beach over the weekend were shocked when a large dorsal fin sliced through the surface of the water, leading many to believe the creature was a shark.
“Shark! Shark!” people can be heard yelling in the background of Kristen Jeno’s now viral video of the event, which took place during the three-and-a-half mile "Swim The Loop" race on Saturday.
“Oh my god, he’s huge!” Jeno says as the massive creature gets closer to the dock — its dorsal fin swaying back and forth as its body moves through the water.
The creature wasn’t a shark at all. Rather, it was an ocean sunfish, also known as a mola mola, The News & Observer reported.
“It was massive. I’ve never seen something quite that size,” Jeno said, according to the publication, adding everyone who spotted the fish is now “fairly certain it was a sunfish.”
Mola mola — the double "mola" comes from the fish’s scientific name, Cool Green Science reported — are “frequently seen basking in the sun near the surface and are often mistaken for sharks when their huge dorsal fins emerge above the water,” according to National Geographic.
These lengthy fish can weigh up to 5,000 pounds, making them the heaviest of all the bony fish, National Geographic reported. (A bony fish is one with a skeleton made of bone and teeth that are “fixed into the upper jaw,” according to the Marine Education Society of Australasia.)
The creatures aren't graceful swimmers; they’re often seen “waggling their large dorsal and anal fins to move and steering with their clavus,” according to National Geographic. The clavus is a “lumpy pseudo-tail” on the fish’s rear-end, Cool Green Nature reported.
Before it was determined the creature was likely a sunfish, Jeno said swimmers had to wait roughly five minutes before they could “brave the sprint across once the coast was ‘clear.'" But there was really no need to worry: Mola mola are not a danger to humans, as these fish feed primarily on jellyfish, small fish and zooplankton, according to National Geographic.
Kristen Jeno was not immediately available for comment when contacted by Fox News on Thursday.