We just got back from the pet store and had an interesting experience watching the fish as we drove home. We purchased 3 blue damselfish. These are the first fish we are adding to our new marine aquarium. On the way home they all started turning dark blue, almost purple. They didn't stay dark, they kept switching back and forth between light and dark. Once we got them into the tank they all changed back to a normal blue color. Has anyone else ever experienced this? Is it common for them to change color? Does anyone know why they did this?
