Hmmm...
Sharks find prey by, among other things, detecting the electric signals from muscle motion or cuts in the fish' skin.
(The hammerhead is so sensitive it can detect the heartbeat of a fish that has buried itself under sand. That's what that "hammer" modification of its head is about: A platform for electrical sensors.) Other fish use a similar system - either alone, or (like the electric catfish) with modified muscles that produce strong electrical pulses which let the sensors detect discontinuities in the water's conductivity caused by the presence of the prey (in addition to being a weapon). I wonder if an electrical signal down the string could fool electric-sensing fish into striking?
Also: Pulses of electricity in the water make fish twitch their main swimming muscles - concave toward the (+) electrode. Put a powerful enough pulsed source in the water and this makes them swim toward the electrode by pure reflex - until they get close enough that the current density stuns them and they float to the surface. (Turn off the current and after a bit and the fish recovers and swims away.) Electric eels seem to use this effect to force fish to swim toward their heads. Probably not useful, though: Takes too much power, is illegal in most jurisdictions, and would knock the fish out rather than getting it to strike.
