A new species of enormous ocean sunfish was discovered after an intensive search, making it the first species of this type of fish to be identified in 130 years.
Despite being the largest bony fish in the world and weighing more than two tons, sunfish are quite elusive, which made the four-year search difficult.
A team of researchers led by Marianne Nyegaard, a PhD student at Murdoch University in Australia, analyzed more than 150 sunfish DNA samples and recognized four distinct species—but only three of the species had been previously identified. (Read about a new species of a transparent frog discovered in Costa Rica.)
This discovery led Nyegaard to believe that there was an additional sunfish species that hadn’t been documented, but she had no idea what it might look like or where it might be hiding.
The research team decided to call the species the hoodwinker sunfish, or Mola tecta, which comes from the Latin word tectus, meaning hidden.It wasn’t until a year after this breakthrough that Nyegaard was able to see a hoodwinker sunfish up close. In 2014, she got a tip from a New Zealand fishery that four sunfish had washed up on a beach in Christchurch, and she flew down to see the evidence for herself.
Researchers from universities all around the world then collected and analyzed specimens from the fish to prove it was indeed part of this new species, and they looked at how it was different from the other three species of sunfish.
The hoodwinker sunfish has a slimmer and sleeker adult body shape and doesn’t develop lumps, bumps, or a snout, like other sunfish, according to the team’s paper published in the Zoological Journal of the Linnean Society.
Since the discovery, Nyegaard and her team have located the hoodwinker sunfish in New Zealand, off Tasmania, south Australia, South Africa, and southern Chile, suggesting the species range might be in colder parts of the Southern Hemisphere, Nyegaard wrote in an article for The Conversation.
The sunfish’s colossal shape allows it to maintain body temperature when it dives deep into the ocean to feed. The size also helps make it buoyant, so it can quickly return to the surface of the ocean to warm up. (Read about a car-sized stingray that could be the world’s largest freshwater fish.)