Eating an ocean sunfish (Mola mola) is not easy. The creatures can reach an impressive 5,000 pounds and their thick skin is as tough as rubber. That means biting most parts of a mola’s body is a bit like biting through a car tyre. But sea lions in California are getting crafty for a taste. (Someone should probably call Jay.)
Image: Ralph Pace/used with permission

This incredible series was shot by renowned photographer Ralph Pace, who witnessed the rare predation off the coast of San Diego. The team had been out on the water searching for sharks to photograph when a flock of frenzied seabirds alerted them to the drama unfolding just below the surface.

"We saw the sea lion thrashing around and as we got closer we saw the fins," he says. "As we slipped into the water, we were sure to stay back and observe from a distance, but as we watched this epic event unfold, the sea lion became more and more comfortable with us and seemed to actually bring the mola closer."

While it's not unheard of for large predators like sharks and orcas to munch the occasional sunfish, sea lions rarely attempt the feat – and certainly not with a specimen of this size. "It's quite uncommon," says Pace. "The sea lions typically rip the fins off molas, but don’t consume them. This one fought, killed and ate the innards for over an hour."  

Molas are slow, deliberate swimmers, but that's no reason to get too close. Not only is this considered wildlife harassment, but the scale-less fish are known to host over 40 different parasites. In fact, some of their parasites even have parasites of their own. 

The sea lion's success here definitely hinged on bite placement. A mola's protective skin and bony underparts are thinnest just below the mouth. By entering the body cavity at that spot, the hungry pinniped was able to burrow straight through. It's possible that the catch came down to luck, but interestingly, nearly all cases of sea lion-eats-sunfish play out this way:

By the time Pace and his team left the scene, the sea lion was chest-deep in the dead fish, pulling out what remained of its guts and stomach (yes, we know, nature is beautiful).

"I have been asked several times now how I could watch or photograph this event," he adds. "And while I do love molas, the event would have taken place whether I had been there or not. My job is simply to document what goes on in the ocean." 

Whether or not recent El Niño weather patters have something to do with the strange sighting is yet unknown. As local squid and sardine populations (the staples of California sea lion diets) continue to move offshore, sea lions may be forced to turn to difficult prey like sunfish for supplemental nutrients.

It's also possible that the sunfish themselves are being affected. Despite their appearance, these animals are extremely athletic and have been known to dive as deep as 2,600 ft (792m) to feed on siphonophores and jellyfish. They return to the surface each day to warm themselves, which allows them to stay at depth for greater intervals. Scientists suspect that shifts in ocean temperatures will effect sunfish behaviour and choice of habitat, but just how remains to be seen. 

Image: Ralph Pace
Image: Ralph Pace
Image: Ralph Pace

Despite its already impressive size in these photographs, this sunfish was certainly still growing. The behemoths can reach 14 feet (4.2 metres) fin to fin – just look at this specimen, last seen cruising off the coast of Portugal:

For more incredible photos of marine life, follow Pace on Instagram.
Top header image: Ralph Pace