I have to agree with most of the above, as well...with reference to marine piscine intelligence, especially. My yellow tang has been with me for about five years. Years ago he began cozying up to my extended "turkey-baster" device. As I was blowing detritus off the corals and live rock, he would nuzzle up to the plastic tip. To this day, when I place the device into the tank, he darts over and wants to be scratched! I am not kidding. I can "pet" this fish for up to five minutes at a time. He will push against the device, or you can push him sideways across the tank as well. I don't think I've ever seen a freshwater fish do something like that!