https://jeb.biologists.org/content/earl ... 5.abstract
Abstract
For thousands of years, starting with detailed accounts in the ancient Egypt, the African electric catfish (Malapteruridae) is renowned for its ability to hunt and to defend itself with powerful electric shocks. Surprisingly, it has never been analysed to what degree electric catfish are protected against their own or external electric shocks, how specific any protection would be to the species-specific waveform and whether it requires a discharging catfish to actively prepare for the onset of its high-voltage discharges. Here we used digital high-speed video to record catfish during their own discharges or as they were exposed to external discharges, always employing goldfish to carefully calibrate the efficiency of all discharges. Electric catfish show a remarkable degree of protection against high voltages: Both self-produced and external electric shocks that heavily affected control goldfish failed to evoke involuntary muscle contraction or to affect sensorimotor processing. Even a commercial electrofishing device, set to efficiently immobilise and narcotise fish, failed to have any effect on the electric catfish. Our findings rule out several protective mechanisms and demonstrate a highly efficient and versatile shielding whose nature is presently unclear.