A newly discovered species of pacu, a piranha-like fish, has been found in the Amazon River, camouflaged among similar species for nearly 200 years. Researchers named it after Sauron from “The Lord of the Rings” due to a distinctive stripe on its side resembling the “Eye of Sauron.”
The new species, Myloplus sauron, was identified while scientists were studying the nearly identical species M. schomburgkii, first discovered in 1841. Genetic analysis revealed that M. schomburgkii was actually three distinct species: M. schomburgkii, M. sauron, and M. aylans. Subtle differences between the species include variations in vertebrae count, dorsal fin rays, and the shape of female anal fins.
Despite its ominous name, M. sauron is not as frightening as it sounds. Pacus, closely related to piranhas, are often mistaken for their more infamous cousins. However, most pacus, including M. sauron, have human-like teeth adapted for a primarily plant-based diet. Even carnivorous piranhas are not as aggressive as popular culture suggests.
The study, published on June 10 in the journal Neotropical Ichthyology, also hints at a potential fourth species in the Tapajós River, identified by large black spots instead of stripes. The genetic differences here were minor, so these fish are currently considered a sub-population of M. schomburgkii.
The name M. sauron was inspired by the dark band on the fish’s side, reminiscent of the “Eye of Sauron.” “Its pattern looks a lot like the Eye of Sauron, especially with the orange patches on its body,” noted study co-author Rupert Collins from the Natural History Museum in London.
This discovery adds to the understanding of pacu diversity and highlights the complexities of species identification in the Amazon’s rich ecosystem.
