When videographer Miguel Perreira shared footage with us of a mammoth Mola mola he'd spotted off Portugal's coast, we didn't think anything could top it. We were wrong. An even wider sunfish has been making appearances near the Maltese island of Gozo.

This stunning video was captured by diver Erik van der Goot back in 2014, the last time the fish was seen. "It was a once-in-a-lifetime experience," he recalls. "The video is a bit shaky as I am trying to outswim the Mola Mola to get it from all sides. The video was shot at a depth of around 15 metres, not more. We rolled off the inflatable, dropped down and there it was."

Some have taken to social media to question the authenticity of the video, but van der Goot explains that the edit features footage from several different dives, with the first clip being a continuous shot. 

"My buddy on that dive, Erik Vestrum, can be seen with a camera, taking pictures. He also took a ten-second video, which I spliced in at around three minutes," he explains. "There is a clear change in sound. The diver in that shot is me swimming next to (and videoing) the Mola."

It's tough to gauge the creature's size without knowing exactly how far away it was from the divers, but van der Goot's height does give us a clue: he's 1.94 metres (6.3ft) tall (minus the fins)! 

Ocean sunfish can reach 4.2 metres fin to fin, and while the behemoth may not be taller than the Portugal specimen, it's possible this bulbous mola is the heaviest one ever recorded.

Scientists suspect size helps these animals thermoregulate in the deep sea. Molas have been clocked at depths of 2,600 feet in search of siphonophores and other prey, and their bulk means they lose heat slowly, and can stay down for longer intervals. When they return to the surface, sunbathing like this helps them warm up.

2.7 mm larval Mola mola. Image: G. David Johnson, Australian Museum/Wikimedia Commons

You might also be surprised to learn that these ocean giants start life small – very small. The fish emerge from their eggs at just one to two millimetres long, and look almost nothing like the adults during early development. Covered in spines, they more closely resemble their cousins, the puffer and boxfishes.

As the sunfish grow, those spines disappear and the clavus (that bulky rear rudder) forms from the caudal (tail) fin rays. And speaking of eggs, we do mean a lot of eggs: this mola likely had 300 million siblings when it first swam into the big blue!


Top header image: blueSkySunHigh/Flickr