Huge Fish Spotted 'Impersonating a Shark' Near California

A large fish has been spotted in the Pacific Ocean off the coast of California that appeared to be "impersonating" a shark.

The ocean sunfish (Mola mola) in question was photographed by the National Oceanic and Atmospheric Administration (NOAA) in the Greater Farallones National Marine Sanctuary. This protected area covers almost 3,300 square miles off the coasts of northern and central California. It is home to a huge variety of marine life, including many threatened or endangered species.

In a photo captured by Sara Heintzelman with the NOAA, the ocean sunfish looks remarkably like a shark.

"Duunnn dun... duunnn dun... wait a second, that's no shark—it's a mola mola! These ocean giants roam the seas in search of their favorite food, jellyfish. This one was spotted impersonating a shark," the NOAA Office of National Marine Sanctuaries wrote in a Facebook post Wednesday.

Mola mola are "unique-looking" fish, Jennifer Stock told Newsweek. She is a spokesperson for the Greater Farallones and Cordell Bank National Marine Sanctuaries.

"They have a truncated tail fin that is somewhat rounded and two elongated fins (dorsal and anal fins). When near the surface, the dorsal fin comes out of the water and can be mistaken for a shark," Stock said.

"With observation, though," she added, "one would see that they are slow and floppy whereas a shark fin is more deliberate. This is a frequent case of mistaken identity from this dorsal fin."

Unlike some animals in nature that employ deliberate mimicry tactics, however, the resemblance in this case in entirely coincidental.

"This photo is a coincidence in looking like a shark from the surface," Stock said. "They eat jellies, so mimicking a shark is not something they do. It only looks like a shark to humans above the water, so no ecological mimicry is going on."

There are six species of sunfish in the family Molidae found around the world. The Mola mola species is the most common one, observed throughout all five West Coast National Marine Sanctuaries.

Mola mola can grow as large as 6 feet from front to back, and their average weight is around 1 metric ton, or roughly 2,200 pounds. The largest ocean sunfish ever recorded weighed in at around 5,000 pounds. In fact, this species is one of the world's heaviest bony fish.

"Sometimes, we see schooling molas when they are smaller and younger, but they tend to be by themselves as adults," Stock said. "They feed on a variety of foods when they are younger, but as they get older, they eat mostly jellies and other types of gelatinous zooplankton—animals that can't swim and are at the mercy of the currents."

Another interesting point about ocean sunfish is that they carry quite a diversity of parasites—more than 40 species have been recorded.

"Various seabirds have been observed picking off parasites off molas when they come to the surface," Stock said. "This is a mutually beneficial relationship—the birds get food, the mola gets cleaned. But sometimes their eyeballs are accidentally picked at, and that is an unfortunate consequence for letting gulls eat your parasites at times!"

Intriguingly, molas have a very thick layer of mucus around their body that protects them from not only bacteria but also UV sunlight when at the surface—almost like a built-in sunscreen.