When I was in Puerto Rico on a consult for Bill Addison of C-Quest, he took me diving on the South side of the island, and we had to walk about 300 yards thru knee deep water ALL of which was 100% covered with Zoanthids. I was told they continued like that for many miles in both directions. My point is, that where they occur, the quantity can be beyond belief. I've collected up and down the Keys, and never worked any shallow, hard bottom areas that didn't have a few or a lot of Zoas and/or Palys. I guess a better question would be, are there any hard bottom, tropical shallows (to 25 or 30') that don't have them? Just my 2 cents, Dick