soft coral

Question
I panic a little when my polyps close and do not seem to reopen for many hours in full light.  I know my cleaner crew is scavenging and cleaning amongst the polyps and this causes them to close.  When should I be concerned regarding the polyps closing?

Answer
Hi Dan. Soft coral polyps will often close up for different reasons. Of course if your cleaner crew are walking over them they will react to this disturbance by closing up. This is completely normal and should not be a cause for concern. They should reopen with in an hour or two when they feel any threat is over. However if they are constantly being tread on by any hermit crabs or shrimps you may want to find new homes for a few of them. Its not so much the walking on them that is bad it is the fact that they are not extended to soak up the light that can cause them harm. If you see the polyps closed up more than they are open this is a bad sign. Some soft coral polyps will also close up when they under go a shedding. This is also a common event and you will see them closed up for a day or two followed by a stringy whitish material coming off of them. This will happen occasionally and is also not a cause for concern. Although if it is happening more than once a month you may have to move them to an area with a better water flow. This shedding behavior is due in part to a detritus build up on the coral polyp itself(although with some soft corals it is a sign of growth). If there is not enough current to blow this build up off of them then they are forced to shed it off in this manner. The problem with this is that if it is happening too often they remain closed up too long and can not utilize enough light for the growth of their zooxanthellate algae in their tissues. Polyps will also close up if your water quality starts to deteriorate and frequent partial water changes and testing should be done to prevent this. I am sure you are aware of that! As long as you are noticing growth and the polyps are fully extended the majority of the time you can stop worrying. Most soft corals are pretty hardy and as long as you are meeting all their requirements for feeding, light and water quality they should be just fine!