I have never heard of lime juice cooking the fish. So its real important that it is done overnight, right? Where does this method originate from? Does this make the fish tender or tough? Lately I have been on the Ceviche kick. Also I use capers on my own made up recipe with shrimp. As I have been searching the recipes for different ingredients, yours is the first to see that capers may be used.

Actually yes lime does cook the fish, so you can see it yourself. Put lime on a piece of red meat preferaby flap meat, and leave it a couple hours in the fridge before cooking. Watch the color of the meat change.