ABSTRACT
For thousands of years, starting with detailed accounts from ancient Egypt, the African electric catfish (Malapteruridae) has been renowned for its ability to hunt and to defend itself with powerful electric shocks. Surprisingly, the degree to which electric catfish are protected against their own or external electric shocks, how specific any protection would be to the species-specific waveform and whether a discharging catfish has to actively prepare for the onset of its high-voltage discharges has never been analysed. Here, we used digital high-speed video to record catfish during their own discharges or as they were exposed to external discharges, 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.
Footnotes
Competing interests
The authors declare no competing or financial interests.
Author contributions
Conceptualization: G.W., S.S.; Methodology: G.W.; Validation: G.W., S.S.; Formal analysis: G.W., S.S.; Investigation: G.W.; Resources: S.S.; Writing - original draft: G.W., S.S.; Visualization: G.W.
Funding
The project was funded by overheads from the Deutsche Forschungsgemeinschaft (DFG grant Schu1470/8).
Supplementary information
Supplementary information available online at https://jeb.biologists.org/lookup/doi/10.1242/jeb.239855.supplemental
- Received October 23, 2020.
- Accepted December 24, 2020.
- © 2021. Published by The Company of Biologists Ltd
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