HI, just thought I would show you a picture of our new Sea Pen. It has been moving around the tank for the last 4 days and has eventually found a spot it likes (i hope ). Opens and closes to the extreme, so tiny you hardly see it and then when open fully (more so under dim lights) it is really wide and tall. It buries its pink foot into the sand and opens itself to catch passing food., when its resting it buries itself completely under the sand bed, where you can hardly see where he is. Not much info out there on them, except they are quite difficult to care for so crossing fingers and going to put a lot of extra time into feeding and looking after. If anyone know about these little things any info would be much appreciated.