Tropical Fish Hobbyist

usually different colors. Oftentimes when found dwelling in live corals, particularly Porites, the worms extend their tubes at about the same rate as the coral colony adds on new skeletal material, so the opening of their tubes end up staying pretty much flush with the surface of the coral colony’s skeleton. Thus, all you’ll usually see of the tube is the spike and operculum right at the surface, with the gills emerging colonies, and not as the worms themselves.

These coral colonies are usually fist-sized heads of Porites that contain several worms that have their tubes inside their skeletons, and nicely enough, the different worms are

Looking just below the gills, you can see this specimen’s operculum.

from the tube’s opening. But in some cases, the entire tube can be seen, just under a thin layer of coral tissue and skeleton.

Also note that these are sometimes called “worm rocks” for some reason, instead of “live stony coral with worms,” which is very misleading for obvious reasons. The coral colony will need very bright lights and everything else that live corals require to survive, meaning that such specimens should only be placed in well-lit reef aquariums if you expect them to live.

Still, there are occasional specimens that really are on rocks/pieces of dead coral. The biggest source for these is no more, however. Many years ago, it was possible to get pieces of live rock collected from Florida waters that were absolutely covered with Christmas tree worms, but the collection of the rock has been stopped—although I’ve seen a few on aquacultured live rock from Florida, and on some hand-picked rock/ dead coral specimens from the Pacific. So there’s a chance that you might be able to come up with some anyway. For what it’s worth, I don’t recall ever seeing any (alive) on pieces of Pacific live rock being sold as bulk rock, which is shipped damp rather than in water.