GYMNOTUS ELECTRICUS.
Date 1796.
Source http://www.flickr.com/photos/biodivlibrary/7064486431
Author Marcus Elieser Bloch
Full title Ichthyologie; ou, Histoire naturelle des poissons : En six parties avec 216 planches dessinées et enluminées d'après nature / par Marc Éliéser Bloch.
Source: https://commons.wikimedia.org/wiki/File:Ichthyologie;_ou,_Histoire_naturelle_des_poissons_(Plate_156)_(7064486431).jpg

The electric eel (Electrophorus electricus) is an electric fish, and the only species in its genus. Despite the name, it is not an eel, but rather a knifefish. Electric eels inhabit fresh waters of the Amazon and Orinoco River basins in South America, in floodplains, swamps, creeks, small rivers, and coastal plains. They often live on muddy bottoms in calm or stagnant waters.