Scientists Discover Sauron Fish, a New Species Resembling Piranha

Updated July 02, 2024 Dan Science

Sauron Fish

A new species of fish similar to a piranha has been discovered in the Amazon River. This fish had been quietly 'disguising' itself as another almost identical species for nearly 200 years.

Discovery of the Sauron Fish

The newly discovered fish was named after the dark lord Sauron from the fantasy tale 'The Lord of the Rings' by J.R.R. Tolkien. This species, scientifically named Myloplus sauron, is a close relative of piranhas often misunderstood as freshwater fish.

Scientists found M. sauron while studying a closely related species, M. schomburgkii, initially discovered in the Amazon in 1841 but largely overlooked by researchers since then.

Genetic Analysis and Differentiation

In a new study published on June 10 in the Neotropical Ichthyology journal, genetic analysis of the M. schomburgkii population revealed that it actually consists of three different species: M. schomburgkii, M. sauron, and M. aylans.

Upon careful observation, researchers noted subtle physiological differences among the three species, including the number of vertebrae and dorsal fins, as well as the shape of the anal fin in females.

Naming and Resemblance

M. sauron, described alongside M. aylans in the new study, was named based on the black line on its side. This line, also present in M. schomburgkii and M. aylans, bears a striking resemblance to the 'Eye of Sauron,' the giant flaming eye controlled by the titular villain in The Lord of the Rings.

Misconceptions about Piranhas and Pacus

Pacus and piranhas, both belonging to the family Serrasalmidae, are often believed to be aggressive blood-thirsty predators. However, most species in both groups are omnivorous and prefer a vegetarian diet.

Contrary to popular belief, even the strictly carnivorous piranhas are not as aggressive as commonly portrayed. This misconception was partly fueled by President Theodore Roosevelt, who wrote in 1913 that piranhas were the fiercest fish in the world after witnessing a demonstration of them tearing apart other fish within minutes during his trip to Brazil.


While the similarities among the three pacu species listed in the new study are evident, researchers are uncertain about their exact relatedness. There is a possibility that they all descended from a common ancestor or evolved convergently to appear similar for survival advantages.

As a result, there is a chance that M. sauron and M. aylans could be reclassified into different genera if they are found to be more closely related to other species.

In conclusion, the discovery of the Sauron Fish sheds light on the intricate biodiversity of the Amazon River and challenges misconceptions about piranhas and pacus.

Published: July 01, 2024

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