Propagation In The Aquarium

Reef aquariums are common in the hobby nowadays. With the increased knowledge of their environmental needs and the ability, with the assistance of technology, to maintain the reefs for long periods, the days of struggling with maintenance should be gone.

Some problems have arisen with the ability to maintain such excellent aquarium conditions and the import of coral rocks and specific live rock. One that springs to mind is aiptasia anemones, the weeds of the aquarium. In addition, with long term success coral growth could cause difficulties.

As corals grow they could possibly cause shadows over other occupants of the reef that also need light, or interfere with each other with ensuing damage. Though many aquarists dislike doing it, corals can quite easily be cut to form new ones, in much the same way that a gardener splits plants to obtain more. This is easier than many realize, though it is understandable that aquarists are nervous when they view the beautiful coral(s) in question. Cutting the corals is generally termed ‘fragging.’

For most aquarists there isn’t a need to have an additional aquarium specifically for growing on cut corals. Some keen aquarists have fairly large shallow aquariums set up complete with lighting etc for just this. The rest of us are able to do it in the display aquarium. The benefit of this is that the corals will continue to exist in the same seawater and under the same lighting, and there aren’t any additional costs involved.

All that is required for soft corals is a pair of sharp scissors and a spare removable rock – a rock that has plenty of holes and crevices that the cutting can be fastened to.

There is a lot of information about ‘fragging’ corals on the internet, so I’ll restrict this to a commonly kept leather coral, the toadstool, properly called Sarcophyton species. They are a good example as the success rates are high – there are plenty of other soft corals that are just as amenable to propagation.

The most straightforward way to double the coral (that is, one becomes two) is to cut the head off. (There are ways of creating multiple corals from one that will not be gone into here.) Sounds drastic! The cutting point should be selected so that at least two thirds of the stalk is left attached to the original point, leaving the rest to attach the remaining stalk with the head. The cut should be completed in one effort (though more shouldn’t destroy the coral) and be clean.

The freed head should be attached to the removable rock by the use of a wooden cocktail stick. This is pushed all the way through the lower stalk, again it sounds a bit drastic. The stick should be pushed home so that it holds tightly in a suitable hole or crevice in the rock. The rock is then carefully placed where it can be temporarily left undisturbed. That’s it! No jiggery-pokery at all.

After two weeks or so, sometimes more quickly, the aquarist will see new polyps starting to form on the stalk from which the head was removed. This will continue until the polyps are as they were when the head was present, and a new head will form over time. It really is Nature’s magic. The coral with the head will, over about the same period of time, put out its polyps once more and attach to the rock. Apart from the shorter stalk, which will grow, there will not be a noticeable difference.

Once the cut stalk is attached to the rock, the rock and coral can be bagged up and given away to an aquarist friend, or taken to the local dealer and exchanged for a credit note or some merchandise. Local dealers are usually willing to do this as it means trade and they are obtaining a saleable coral.

As said, it is not just Sarcophyton sp corals that can be propagated; there are many soft corals that will co-operate.

Hard corals (SPS) can be ‘fragged’ in a similar way. This time however, they are not cut but a branch is snapped off. The mother coral that is to be used must be healthy and vigorous; it is likely it will be as that’s why the aquarist wishes to reduce its size. Though the coral will need to be handled, handling should be as gentle as possible and minimized.

Instead of a pair of scissors the aquarist could use pliers to assist in breaking the branch off, though often the fingers are just as good. Select a good branch and snap it off near the base. Once snapped off, it could be placed in a hole or crevice in a removable rock as was the soft coral. There is a better way though which will allow the rock to be used over and over again. This is to use a short plastic tube cut from a longer length (reef safe plastic). The tube can be purchased with a useful diameter so that the cut coral sits in loosely but is held upright. Put the short length of plastic in a suitable hole or crevice in the rock, and place the coral in the tube. That’s it, job done.

After two weeks plus the coral should adhere by growth to the tube and growth should be evident at the tip. At a time suitable to the aquarist the tube with coral can be removed from the rock. It can then, as before, go to another aquarist or to a local dealer.

So with soft or hard corals, very little effort, plus zero additional expenditure, the aquarist can control any overgrowth of corals and at the same time increase the stock within the hobby. It doesn’t matter that it is only by one or two, the fact is it matters – and it’s easy.

Should there be a desire to read more here’s a link:

1 Comment
  1. Just some of my own additional tips:

    For fragging corals like xenia, leather, colt, kenya tree cut off the frag with a razor blade. Then use a needle and fishing line to tie the frag to a rock or frag plug. Poke the needle through the coral in a couple of places to sew the frag to the rock. In a couple of weeks you can cut the line away, as the coral will have attached to the rock.

    For SPS frags, make a sharp break and immediately dip the coral in an iodine or coral cure solution, I prefer ReVive. Then super glue the coral to the plug using super glue gel.

Comments are closed.