Unexpected species diversity in electric eels with a description of the strongest living bioelectricity generator

Abstract

Is there only one electric eel species? For two and a half centuries since its description by Linnaeus, Electrophorus electricus has captivated humankind by its capacity to generate strong electric discharges. Despite the importance of Electrophorus in multiple fields of science, the possibility of additional species-level diversity in the genus, which could also reveal a hidden variety of substances and bioelectrogenic functions, has hitherto not been explored. Here, based on overwhelming patterns of genetic, morphological, and ecological data, we reject the hypothesis of a single species broadly distributed throughout Greater Amazonia. Our analyses readily identify three major lineages that diverged during the Miocene and Pliocene—two of which warrant recognition as new species. For one of the new species, we recorded a discharge of 860 V, well above 650 V previously cited for Electrophorus, making it the strongest living bioelectricity generator.

An inventory of Ichthyofauna of the Pindaré River drainage, Mearim River basin, Northeastern Brazil

“…lyra), which makes taxonomic studies difficult. It is important to emphasize that in the last two decades several new species occurring in the Mearim River basin have been described, what reinforces this possibility that these taxa could be still undescribed species (e.g., Ferraris & Vari 1999, Triques 1999, Lucena 2003, 2007, Piorski et al 2008, Bragança & Costa 2011, Ottoni 2011Guimarães et al 2018, Leão et al 2019, Santana et al 2019. From the 98 native species herein recorded, 32 of them were not possible to be accurately identified at the species level.…”

A new and improved electric fish finder with resources for printed circuit board fabrication

“…Electric eels generate higher voltage EODs in the form of relatively weak electrolocation pulses generated from the Sach's organ and posterior one-third of the Hunter's organ (ca. 10V) and very strong predatory/defensive EODs (to 860V) generated from the main organ and anterior two-thirds of the Hunter's organ (Crampton, 2019;de Santana et al, 2019). In streams of ca.…”

Diet composition of the electric eel Electrophorus voltai (Pisces: Gymnotidae) in the Brazilian Amazon region

“…Electrophorus Gill, 1864, is a genus of electric eels of the Gymnotidae family that can generate high electrical discharges ‐ (De Santana et al ., 2019). The species Electrophorus voltai inhabits the Amazon region and remains little known.…”

“…The dietary habit of some species of electric eels has been characterised as piscivorous (Bullock et al, 1979;Mago-Leccia, 1994;Mendes-Junior et al, 2016;Sa-Oliveira et al, 2014;Soares et al, 1986;Stoddard, 1999;Westby, 1988), carnivorous (Crampton & Ribeiro, 2013;Ellis, 1913;Giora et al, 2014;Goulding et al, 1988;Mérona & Rankin-de-Mérona, 2004;Oliveira et al, 2019;Planquette et al, 1996;Saul, 1975;Sterba, 1959;Stoddard et al, 2019) or omnivorous (Goulding, 1980;Nakashima, 1941). Nonetheless, no studies regarding the diet composition of E. voltai exist De Santana et al, 2019. This electric eel has the strongest generation of electrical current at 860 V (De Santana et al, 2019). E. voltai is found in the Amazon River system in Brazil and rivers within the Guyana shield (Froese and Pauly, 2019).…”

“…Callichthyidae catfish are notorious for their antipredation adaptation of having dermal plates and spines on their fins, which limits their predators to a few large piscivorous fish (Mol, 1996). The electric eel Electrophorus varii De Santana et al, 2019 is also piscivorous and consumes other Callichthyidae species, but preys on a greater variety of fish groups than E. voltai. The results from the present study contribute to the knowledge of the biology of the legendary electric eels of the Amazon region.…”