See the World’s Heaviest Bony Fish, Which Tips the Scales at a Staggering 3 Tons

Talk about an absolute unit. A team of researchers released a study this week on what they’re calling “the heaviest bony fish in the world,” a giant sunfish found dead and floating in the Azores in the Atlantic Ocean in late 2021. 

Bony fish, as the description suggests, have skeletons made of bone, in contrast to ocean dwellers with skeletons mainly made up of cartilage, like sharks. The scale-tipping sunfish (Mola alexandrini) clocked in at 6,050 pounds (2,744 kilograms).

The previous record holder was a sunfish captured in Japan in 1996 that came in at 5,070 pounds (2,300 kilograms). Marine scientist Jose Nuno Gomes-Pereira with ocean conservation and research nonprofit Atlantic Naturalist led the study, which was published in the Journal of Fish Biology. Atlantic Naturalist shared a video of the fishy find on Thursday showing the sunfish being examined and lifted with heavy equipment for weighing.

An investigation of the fish carcass found a large contusion on its head likely caused by a boat, but the scientists weren’t able to determine if the impact happened before or after the sunfish died. While gigantic, sunfish are gentle giants that aren’t dangerous to humans, though they have accidentally become entangled with boats.  Atlantic Naturalist said the giant sunfish’s existence shows the ocean is “still healthy enough to support the world’s largest animals,” but also called out ocean pollution and boat traffic as a concern for the animals. 

Guinness World Records — keeper of all sorts of record-breaking activities, creatures and oddities — still lists the Japanese sunfish from 1996 as the world’s heaviest, but it may have to update its bony-fish entry with this new information.