DNA research has revealed two completely new species of electric eels in the Amazon basin, one of which can provide a record-breaking shock.
The results are tests, the researchers argue, of the incredible diversity in the Amazon rainforest – largely still unknown to science – and illustrate why it is so important to protect a habitat at risk from deforestation, logging and fires.
"Despite the human impact on the Amazon rain forest over the past 50 years, we can still discover giant fish like the two new species of electric eels," said chief researcher C David de Santana, a zoologist working with the National Museum Smithsonian of Natural History.
The research "indicates that a huge amount of species is waiting to be discovered in the Amazon rainforest, many of which can cater for diseases or inspire technological innovations," he said.
The electric eel, which is a species of fish rather than an eel, inspired the design of the first electric battery.
For centuries, it was believed that there was only one species in the entire region known as the Great Amazon, which included parts of countries including Brazil, Surinam and Guyana.
But in a project to better understand electric eels and map wildlife in remote parts of South America, de Santana and his team decided to test this theory.
At first glance, they found little visible difference between creatures gathered from different parts of the Amazon basin, suggesting that the fish were actually part of a single species.
But further analysis, including the DNA of 107 collected samples, reversed centuries of hypothesis and revealed three species: the previously known Electric electro-hole, with I turn over is Electrophorus varii.
And their research also found another surprising result: E. voltai it is capable of delivering a shock of 860 volts – much more than the 650 volts previously recorded by electric eels – "making it the most powerful bioelectricity generator known".
The results, published Tuesday in the journal Nature Communications, theorize that the three species evolved from a shared ancestor millions of years ago.
The researchers found that each of the three species had a clearly defined habitat, with E. electricus live in the region of the Guiana shield, E. voltai in the Brazilian shield, a plateau further south, e E. varii to live in the waters of the Amazon basin of the slow-flowing plains.
And they suggest that the particularly strong electric shock that E. voltai can produce could be an adaptation to life in highland waters, where the conductivity is reduced.
Electric eels use their shock tactics for a variety of reasons, including hunting prey, self-defense and navigation. They generate electricity from three specialized electrical organs that can emit charges of different intensities for different purposes.
But the discovery of new species raises the possibility that different types of eels may have developed different ways of generating electricity, perhaps more suited to their different environments.
"The physiology of the electric eel inspired the design of Volta's first electric battery, provided a basis … for the treatment of neurodegenerative diseases and recently promoted the advancement of hydrogel batteries. they could be used to feed medical implants, "said de Santana.