Does anyone know where I can buy small battery operated fish?

I am having a wedding in June and I plan on having fish in my centerpieces. I do not want real fish for multiple reasons so I wanted to put battery operated fish in the bowls. Does anyone know where I can purchase them? I know that they make the large ones for pools but I am looking at having one in a 21" cylinder vase. There is a lot of room for the fish to swim around in. Thanks in advance.