Record-breaking bony fish weighing 3 tons found

(CNN) — A giant sunfish believed to be the world’s heaviest bony fish has been discovered in the Azores archipelago, Portugal, weighing a whopping 2,744 kilograms (3 tons).

Researchers said the animal was found dead, floating near Faial Island in the central North Atlantic in December.

Although found last year, details of the discovery have only recently been published in the Journal of Fish Biology.

Studied by researchers from the Atlantic Naturalist Association and the Azores University for biometrical and morphological data, both in Portugal, the fish was pulled to shore where the animal was weighed, measured and tissue sampled for DNA testing.

There are around 29,000 species of bony fish, which have a skeletal bone structure, making them the majority of the world’s fish species.

The carcass is more than 400 kilograms (882 pounds) heavier than the previous world record holder for heaviest bony fish — a 2,300-kilogram (5,070-pound) female giant sunfish caught off Kamogawa in Japan in 1996.

The sunfish was weighed with a crane scale dynamometer — a device designed to weigh loads typically hoisted by a crane — after being raised above ground using a forklift truck.

The animal was 3.25 meters (10.67 feet) long and had a height of 3.59 meters (11.78 feet). Measured around its center (mid-body), it had a maximum width of 86 centimeters (2.82 feet), researchers said. The sex has not been determined.

José Nuno Gomes-Pereira, lead author of the paper and postdoctoral researcher from the Atlantic Naturalist Association, told CNN Tuesday that it was saddening “to see the animal in this situation as it must have been a king of open ocean.”

The “tremendously big” sunfish has been buried in the Natural Park of Faial Island, he added.

Gomes-Pereira said that the finding was a “sign that the oceans are still healthy enough to sustain the heaviest species existing, but a warning for more conservation in terms of pollution and boat traffic near oceanic islands.”

Giant sunfish (Mola alexandrini) were first recognized as their own species in 2018 and are known to weigh twice as much as the second heaviest fish species, the ocean sunfish (Mola mola), according to a news release from the Atlantic Naturalist Association last Thursday.

Gomes-Pereira said the dead sunfish had a “contusion” — a bruise — on its front, which may have caused the animal’s death. However, it is unknown if the impact was pre- or post-mortem. The wound was embedded with a red paint normally used to coat the keels of boats, the journal article added.

With little data available on large specimens such as the sunfish, the researchers believe further study is required to understand their physiology and marine ecosystems in general.

The world’s heaviest fish species is the whale shark (Rhincodon typus), according to Guinness World Records, with the heaviest found in Pakistan in 1949, weighing 21.5 metric tons.