sunfish on the beach
July 26, 2017

Researchers discover first new sunfish species in 130 years

For the first time in more than a century, researchers have discovered a new species of sunfish – a creature that could grow to nearly 10 feet (3 meters) in size and weigh at least two metric tons, and which is described in a recent edition of the Zoological Journal of the Linnean Society.

The previously unknown species has been dubbed the Hoodwinker Sunfish (Mola tecta), and as Mashable explained, it was discovered by Australian Ph. D. student Marianne Nyegaard and her colleagues after a four-year hunt that started with samples of the creature’s skin and DNA.

As Nyegaard explained on the website The Conversation, she analyzed more than 150 samples of sunfish DNA as part of a population study conducted off the coast of Bali in Indonesia as part of her doctoral research. Sequencing the genomes of those samples revealed four distinct species of sunfish – three which were known, and a fourth that had never been identified.

Initially, “we didn’t even know what they looked like. All we had were skin samples containing the mysterious DNA,” she wrote. “The next step was trying to figure out what these fish might look like. Superficially, all sunfish look the same (that is, slightly strange)... So I started looking at pictures of sunfish, especially on social media, searching for something different.”

Finally, in 2014, she received pictures of sunfish spotted in Australia and New Zealand that had a strange structure on its back. Shortly thereafter, four of the creatures wound up becoming trapped on a beach in Christchurch, New Zealand, allowing her to get an up-close at the new species.

What the Hoodwinker Sunfish looks like (and how it got its name)

Unlike its relatives, the Hoodwinker Sunfish does not develop odd bumps on their head, chin and nose as they grow – their body dimensions change little as they grow older, Nyegaard said. Their back fins was also separated into upper and lower portions by a tiny, flexible piece of skin named the “back-fold,” and the creatures grow to sizes between 50 centimeters and 2.5 meters.

The Hoodwinker Sunfish is the first addition to the Mola genus in 130 years, Mashable said, and while its complete range remains unknown, it has been discovered throughout New Zealand (and particularly around the Southern Island), as well as Tasmania, South Australia, both Victoria and New South Wales (Australia), South Africa and southern Chile, the authors noted.

Based on the locations where the new species has been found, the researchers concluded that it appears to prefer swimming in colder waters. Furthermore, as is the case with most other sunfish, the Mola tecta appears to feed during deep dives into the water. Three of the specimens that they discovered had salps (a gelatinous sea creature somewhat similar to a jellyfish) in their digestive tracts, the researchers said.

“The new species managed to evade discovery for nearly three centuries by ‘hiding’ in a messy history of sunfish taxonomy, partially because they are so difficult to preserve and study, even for natural history museums,” Nyegaard, who was a student at the Murdoch University School of Veterinary and Life Sciences, explained in a statement. “That is why we named it Mola tecta (the Hoodwinker Sunfish), derived from the Latin tectus, meaning disguised or hidden.”

Confirming the status of the new species was not easy, she added: “The process we had to go through... included consulting publications from as far back as the 1500s, some of which also included descriptions of mermen and fantastical sea monsters... We retraced the steps of early naturalists and taxonomists to understand how such a large fish could have evaded discovery all this time. Overall we felt science had been repeatedly tricked by this cheeky species, which is why we named it the Hoodwinker.”

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Image credit: Murdoch University