The toadstool coral or mushroom leather coral, (Sarcophyton sp), are hardy and very decorative. They can grow to quite a size but this varies and is not usually a problem. These corals are suitable for a new aquarist, and, with some experience under the belt, are easy to propagate by cutting. More advanced aquarists who are ‘into’ soft corals often have a toadstool in their collection.
As the name implies, they look a little like a toadstool, but often have convolutions on the head. The usual open state is that they are expanded and many polyps extend from the upper surface of the head. If there is a clownfish in the aquarium, they will sometimes adopt a toadstool coral as home, nestling in among the polyps, which doesn’t seem to harm or bother the coral.
Sarcophyton sp. close down in the same way as other corals. They deflate and have their polyps withdrawn. Sometimes the polyps are only partially extended, and sometimes diffferent areas are not extended at all, giving a clumpy effect.
The question arose because a toadstool that had been healthy had closed up for a while. The coral had closed down normally, had opened the next day but with less polyps extended, the next with even less, and the next with none. When open it was noticed that the coral had discoloured patches on the surface of the head, and these areas had a waxy appearance. The coral stayed closed for a day or two, then began opening in reverse sequence, more and more polyps extending as time passed. Surface skin was sloughing off in the water current. This skin, not large in area, did not seem to affect any other coral. The discoloured areas disappeared and the polyps became fully extended and all present once again.
The coral was not rotting as the aquarist had feared. It was simply getting rid of surface skin. Presumably this is a possible routine occurrence on this species of coral, perhaps a means of ejecting any unwelcome passengers such as algae, accumulated dirt or even parasites.
A coral that is behaving in a different manner to normal needs observation over time. Some soft corals can stay closed for a week or more, then inflate and be as beautiful as ever.
If the period of closure seems just too long, and rot does seem to be a problem, then the coral can be carefully checked – rotting should be apparent if the area is gently squeezed with the fingers as it will tend to be excessively squashy and may break up (generally touching corals should be minimized, not touching at all in normal circumstances). Rotten parts can be cut away with a sharp pair of scissors or a suitable knife, cutting slightly into the good flesh to ensure all rot is removed. All things being equal the remarkable regenerative power of the coral will come into play.