Obviously the first thing we need to know in order to explain this is how an electric eel doesn't electrocute itself. You haven't researched this at all, have you? So, you tell me what the mechanism is, and I for my part will tell you how it evolved. Deal?
OK, so no-one knows what the mechanism is, but the creationists wants us to explain how it evolved.
What a wonderful creationist argument. "There's this ... thing ... which I can't describe ... and which no-one knows anything about ... how do you explain that?"