A southern sunfish (Mola Alexandrini) discovered dead off the coast of Faial Island in the Azores has broken the world record for the heaviest bony fish, though boneless fish weigh more.
|The world's largest sunfish AtlanticNaturalist.org|
The world's heaviest bony fish, a dead southern sunfish (Mola alexandrini) discovered near the Azores in the Atlantic, weighed in at 2744 kilograms.
While there are heavier fish without bones, such as the cartilage-filled whale shark (Rhincodon typus), which can weigh more than 20 tonnes, the previous record holder for the world's heaviest bony fish was also a southern sunfish, which weighed 2300 kilograms and was 272-centimetres long and was discovered in Kamogawa, Japan, in 1996.
José Nuno Gomes-Pereira of the Atlantic Naturalist Association in Portugal and his colleagues discovered a large, dead sunfish floating off the coast of Faial Island in December 2021. Gomes-Pereira and his team were able to drag the carcass to shore in order to weigh, measure, and collect DNA from the fish.
They weighed it with a crane at 2744 kilograms, more than 400 kilograms heavier than the previous heaviest, and 325 cm in length.
While they don't know what killed the fish, they discovered a large semi-cylindrical depression near its head marked with red paint, similar to what's seen on a boat's keel. However, it is unclear whether this mark occurred before or after the fish died.
Journal reference: Journal of Fish Biology, DOI: 10.1111/jfb.15244