Electric eels

Electric eels are famous, and rightly so. They have a storied history as perhaps the first model species in science, having been used to explore the link between biology and electricity since the 1700s. In 1775, John Walsh obtained the all-important 'spark' from an electric eel, suggesting man-made electricity and animal electricity are equivalent. In the year 1800 Alessandro Volta invented the first battery based on the anatomy of the eel's biological batteries (electrocytes). In the same year Alexander von Humbolt purportedly observed the extraordinary spectacle of South American fishermen herding horses into a pool containing electric eels. His description of the ensuing battle was published in 1807, catapulting electric eels (and Humbolt) to world fame. Later, in 1838, Michael Faraday - the father of modern electrostatics - published an extensive investigation of electric eel discharges, sealing the case for biologically generated electricity and kicking off modern studies of physiology. These and other studies presaged Krogh's principle in biology - that there is an animal of choice best suited for a particular biological problem - long before August Krogh was born.