I love this rock and the crushed shell substrate is beautiful. I have seen lots of snails, a few gorilla crabs, several brittle starfish, baby hermit crabs, one mantis, lancelets, small shrimp, worms of various shapes, barnacles, mollusks, tunicates, feather dusters, sponges, corals, macro algae and more. Here are a few of the photos I have taken thus far.