In case you have some free time on your hands and don’t mind playing with electricity, here’s Cameron Duke in NewScientist (20 March 2021, paywall) on the mystery of electric catfish:
By Stan Shebs, CC BY-SA 3.0, Link
The electric catfish can emit up to 300 volts to stun its unsuspecting prey. However, the fish isn’t just immune to its own jolts – it seems to be unable to be shocked at all.
Georg Welzel and Stefan Schuster at University of Bayreuth in Germany explored the degree to which electric catfish (Malapterurus beniensis) are insulated from electric shocks, both their own and those from outside sources.
In one test, in which a goldfish and one of the two electric catfish used in these trials shared a tank, Welzel and Schuster coaxed the catfish into discharging its electricity by gently brushing its tail. In another, they used a commercial electrofishing device to give the entire tank a jolt. In both trials, the goldfish spasmed and contorted its body briefly before recovering, but the catfish was unaffected.
“It was absolutely amazing to see how unexpressed and relaxed electric catfish swam through their tank when being confronted with electric shocks that usually narcotise other fish,” says Welzel.
And as it’s thought that the fish hunts by sensing the electric field of prey, it’s not as if he’s super-calloused or something.
