If the marine environment is of high quality then the occupants should do well. This includes the growth of corals which of course is good. However, this in itself can demand attention from the aquarist.
Some soft branching corals can show very significant growth.This could interfere with seawater flow and light availability – other corals could suffer because of it. A large branch over a smallish coral, throwing it into shade, could mean problems for that coral if the aquarist let things be.
So what can be done? It’s a little worrying when the question of cutting a coral arises and the thought ‘What if?’ comes to mind. The fact is that provided the environment is good corals repond well to trimming. The trimming shouldn’t be too severe of course and thought needs to be given to where and how. The where is easy, it’s the offending branch. The how is also easy, just some care is required.
All that is required in the way of equipment is a pair of quite long and definitely sharp scissors and a bowl to put the cut off coral in. A sharp knife of good length could also be used but scissors tend to permit more accuracy generally.
It’s not time for cutting just yet. First, the cut point should be made where the coral will not be left looking out of balance, that is, it should still look normal when the branch is removed. Usually the cut is made near to the main stem and a very small distance away from it.
Once the cut point has been decided and before the coral shrinks because of interference from the aquarist, the size of the cut off branch should be noted. Is there anywhere in the aquarium that it could be relocated? If there is then it can be securely placed between rocks. If not, then the plastic bowl will hold the piece until it can be transported to the dealers (speak to them first) or passed on to another aquarist. Before being transported in a plastic bag the cut off coral can be placed in seawater in the bowl and the bowl floated in the aquarium to maintain temperature.
The time has come for the cut to be made. Before approaching the coral the aquarist should note the angle the scissors will need to be at. Hands into the aquarium and with the scissors placed as required a single cut right across the base of the the branch should be made – do not open and shut the scissors as would be done when cutting a length of cloth, what is needed is a straight neat cut without any hacking. The branch should come away completely. Sometimes the branch is still fixed to the stem by a shred of coral – cut this also in one movement. The cut branch should never be pulled off by shearing any attachment by force.
The coral will of course react, quite understandably really! It will shrink and go into ‘sulk’ mode. It could also eject some milky substance into the seawater, this is a result of deflation and usually not a concern. The coral will remain closed up for a day or so but will inflate again. The coral should be watched for any sign of rot around the cutting site, this is unlikely if the job has been neatly done. If any rot does occur then it should be removed with about 1/4″ of the cut into healthy coral. For cuts of this type a very sharp knife is generally best.
The photo at the head of this text shows a coral two days after being trimmed. In the photo below the branch on the left of the coral is re-growth from a similar trimming operation which occurred about five months earlier.
Generally speaking corals have a high capacity to re-grow. The re-growth is likely to be different from the original, and where one branch has been removed for example two could re-grow, each of a smaller diameter or just one again. Corals can be trimmed time and again and provided the trimming is not too severe there will usually not be a problem.
Trimming corals has the advantage that additional corals are being produced for use by the aquarist, other aquarists or for the dealer. This is good for the hobby and the reefs. An aquarist who designs a reef carefully could fully populate it over time by using additional corals, although this is not so good an option from the point of view of captive reef variety.
Maintaining an established reef is simple overall – provide a high quality environment, properly populate and take necessary actions following observation, such as the one described here.