A new species of piranha-like fish has been discovered in the Amazon after secretly disguising itself as another, almost identical species for almost 200 years. Scientists have named the newly discovered fish after the dark lord Sauron from JRR Tolkien’s fantasy epic ‘The Lord of the Rings’.
However, the fish is not nearly as scary as its sinister name implies.
The newly identified species, Myloplus sauron, is a pacu – a close relative of piranhas that are often confused with the iconic freshwater fish. Researchers discovered M. Sauron as they studied the nearly identical species M. schomburgkiiwhich was first discovered in the Amazon in 1841, but has since been largely ignored by scientists.
In a new study, published June 10 in the journal Neotropical ichthyologyscientists conducted a genetic analysis of the M. schomburgkii population, which showed that it actually consisted of three different species: M. schomburgkii, M. Sauron And M. Aylans. After closely examining the fish, the researchers also noticed almost imperceptible physiological differences between the three species, including the number of vertebrae and dorsal fin rays, and the shape of the anal fins in females.
M. Sauronwhich was described below M.aylans in the new study is named after a black band on its side. This line, which is also present on M. schomburgkii And M. Aylansbears a striking resemblance to the ‘Eye of Sauron’ – a giant fiery eye controlled by the titular villain.
“The pattern looks a lot like the Eye of Sauron, especially with the orange spots on its body,” study co-author Rupert Collinssaid the senior curator of fish at the Natural History Museum in London in a rack. “As soon as one of my colleagues came up with the name for this fish, we knew it was perfect for it.”
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Pacus and piranhas, both of which belong to the Serrasalmidae family, are often considered aggressive, bloodthirsty predators. But a majority of both groups are actually omnivores and prefer a primarily plant-based diet. Most pacus are e.g. have flattened, human-like teeth which help them break down plant material instead of tearing through the flesh.
Even the purely carnivorous species of piranhas are not as aggressive as most people think – a misconception fueled in part by President Theodore Roosevelt, who wrote in 1913 that piranhas were the “most ferocious fish in the world” after seeing a demonstration of the fish tearing the flesh from a cow in minutes during a trip to Brazil. What Roosevelt actually saw, however, was a group of piranhas that had been deliberately rounded up and starved to drive them into a feeding frenzy.
Despite the similarities between the three pacu species mentioned in the new study, researchers aren’t sure how closely related the three fish are. It is possible that they all descended from one recent ancestor. But it’s also possible that they are distantly related and all evolved to look the same because this gave them the best chance of survival in their environment – a phenomenon known as convergent evolution.
“There wasn’t enough evidence to suggest whether these three species all descended from one common ancestor, or whether they evolved convergently,” Collins said.
As a result, it is possible that M. Sauron And M. Aylans could be moved to different genera if they are later found to be more closely related to other species, researchers wrote.
Researchers also identified a potential fourth pacu species in the Tapajós River – a tributary that flows along the Amazon – that had large black spots instead of stripes on the side. However, the genetic differences between these fish and M. schomburgkii were “borderline,” Collins said. Therefore, they are currently labeled as a subpopulation of M. schomburgkii.