A giant, ‘sunbathing’ fish that washed ashore in Oregon turned out to be an unexpected oddity

The name “mola” comes from Latin and means “milestone,” which refers to the fish’s flat and circular body. The fish are known for floating along the ocean’s surface — what some scientists lightheartedly refer to as “sunbathing.”

But Nyegaard said the activity serves an important purpose: catching jellyfish and other gelatinous creatures for prey.

Sunfish dive deep down into colder water when they hunt. Since their bodies cannot efficiently regulate temperature, they warm themselves using the sun. While the fish lie on the ocean’s surface, birds clean them by eating parasites off their skin. 

Certain features of hoodwinker sunfish distinguish them from ocean sunfish, Nyegaard said. As ocean sunfish grow, their skin wrinkles. Hoodwinker sunfish are always completely smooth. 

Where a normal fish would have a tail, sunfish have a flap. An ocean sunfish’s flap is wavy and has bony formations. The hoodwinker sunfish’s flap is divided into two, and it can move each part independently of the other.

“Why those two species need different backends, we don’t know,” Nyegaard said. Some theories are that they need the two-part flap for steering or agility, she said. 

Nyegaard said sunfish in general are still mysterious to scientists. There are five species in total, including the hoodwinker, but it’s unclear how or if they can co-exist in the same location. 

It’s also unclear if the hoodwinker fish in Australia and New Zealand are linked to the ones in the Pacific Northwest and have somehow migrated across the equator, Nyegaard said.

Since the discovery, people have flocked to Gearhart Beach to visit the lone hoodwinker on the sand. 

“It’s not the first time it’s washed up, but it is the largest one to wash up,” said Tierny Thys, a marine biologist at California Academy of Sciences. 

“Strandings like this remind us how humans inhabit a mere 1% of the available living space on this vast ocean planet,” she said. “It’s both humbling and inspiring to encounter one of these incredible creatures and a powerful reminder we have so much more to learn.”