Not just a big fish, but probably the biggest bony fish ever

It was easy for scientists to have doubts when they were told that the carcass of a giant fish was found floating off the coast of Faial Island in the Portuguese Azores archipelago in the mid-Atlantic in December 2021. People tend to exaggerate when it comes to the size of the fish after all. However, their doubts faded the moment they set their eyes on the fish. It was the largest bony fish they had ever seen. In fact, it was probably the biggest thing anyone had ever seen.

Weighing in at over 6,000 pounds, the massive southern sunfish, roughly the same weight as a Chevrolet Suburban, is over 10 feet in length. Scientists say the fish, a type of mola, was the heaviest bony fish ever recorded.

More than 90 percent of fish have skeletons and thus fall into the bony fish category. This distinguishes them from sharks, rays, and some fish that have cartilaginous skeletons. Although no bony fish comes close to the size of a whale shark, the largest cartilaginous fish, the size of the Azores sunfish is impressive.

“It’s very rare to find a big fish these days due to overfishing and habitat degradation,” said Corey Evans, a fish ecologist at Rice University who was not involved in the discovery of the SUV-sized sunfish.

The last bony fish recorded anywhere close to this size was a female of the same species caught in Japan in 1996 that weighed about 5,070 pounds and had a diameter of approximately 8.9 feet.

Jose Nuno Gomez Pereira, marine biologist with the Atlantic Naturalist and co-author of study It was published earlier this month in the Journal of Fish Biology that it documented the sample. “These species can reach this size. We were finally able to weigh and measure one. There are more of these monsters out there.”

Regardless of their size, moolas are known for their clumsy swimming style. Unlike most fish, molars use their dorsal and anal fins to propel their massive, massive bodies through the water, which they do slowly and randomly. Open ocean fish are often seen perched on their sides, which scientists believe heat up or make it easier for seabirds to prepare a meal of parasites on their skin.

After local fishermen and barges found a southern sunfish floating near the Azores, a group of scientists from the nonprofit Atlantic Natural Research Organization and local marine wildlife authorities dragged its body into the port of Horta and lifted it to land using a forklift.

Dr. Gomez Pereira and his colleagues spent several hours measuring the fish’s length, weight and stomach contents. The skin of the mola, about eight inches thick, made the dissection particularly difficult. Since the fish were too large for any local museum to preserve, they were buried on the slope of a nearby hill.

Scientists have not been able to determine the exact age of the fish, but Dr. Gomez Pereira believes the creature was at least two decades old. It is estimated that this is close to their maximum lifespan, but no one really knows how long these animals can live.

Perhaps the life of this particular fish was cut short. While examining the fish, Dr. Gomez Pereira noticed a large bruise on the side of the animal’s head. This could be a sign that the boat hit the fish. Scientists believe boaters in the Azores need to slow down and be more aware of their impact on ocean wildlife.

At the same time, Dr. Gomez Pereira hopes that the discovery of this fish will show people that the ocean is still healthy enough to support the largest animals on the planet, as well as inspire them to do more to protect it. “It is a warning to us regarding the need for further conservation measures,” he said.