Is it possible for an organism to evolve a capacitor if the conditions were right (carnivore that stuns fish, living in complete darkness, etc.)? What kind of challenges would there be to evolve something like this? What fluid would it most likely be present in? I was looking at Wikipedia's page on electric eels and was just wondering about this. I'm learning about electrical fields and voltages in my college classes right now.
A capacitor is, in its bare components, a dielectric separating two opposite charges.
An electric eel creates its discharge by separating ions via an energy pump and opening the channel on demand.
Therefore, in a way, living organisms have already evolved a capacitor. It doesn't come with the package we see in printed boards, it has no color coding, but it does its job.