Propagating Nepthea sp. and Lobophytum crassum

My friend, Brian, at Greene Mariculture offered a lime green Nepthea for auction at a local club meeting a couple of years ago. At the time he hadn't sold any fragments because it was a slow growing coral. Having slow growing corals in nano tanks is not a bad thing, so I bought the fragment at the auction. Although I may have paid more than I wanted to, it was for the good of the club.

The horizontal trunk was vertical until it reached the water’s surface. With nowhere to go it leaned over and spread horizontally, with shoots coming off the top of the main trunk. It's time to rein in the growth, fragment a small piece for my tank and find a home for the mother colony.

Corals of the order Alcyonacea, such as Sinularia, Sarcophyton, Lobophytum and Nepthea genera, are generally lumped under the common name "leather corals." These are some of the easiest corals to propagate, even for beginners who have never taken a tool to their prized corals. Unlike Xenia and mushroom corals that shrink and collapse when fragmented, leather corals retain their shape and rigidity even after being cut for propagation.

The first step is to remove a piece from the original colony. Here, I'm using a surgical grade stainless steel scissors and just cutting a branch off the mother colony. It's been mentioned that using a scissors can damage corals by crushing tissue as its being severed. For the small piece I'm removing, damage from the scissors is minimal; but if I needed to remove the mother colony at its base, a fresh razor blade would be my tool of choice.

I prefer to use live rock rubble to mount fragments; they look much more natural than manufactured plugs in a display tank. In this case the rubble has a natural indentation so when the coral is attached with a rubber band, there's very little pressure on the coral’s tissue.

As shown in the two photos above, it's not unusual for both corals to close up after being fragmented. Make sure they have good water flow and excellent water parameters, and they'll return to normal shortly.

Other methods can be used to attach leather corals once they're fragmented, and this isn't meant to be the definitive technique. It is, however, meant to make the process so easy that you have no excuse not to fragment your corals and trade with other hobbyists. Not only is this a cost effective way to increase your personal stock of corals, but it also helps reduce the hobby's dependence on wild-collected corals.

Now that you've successfully taken a small fragment off a large coral, it may be time to propagate a coral that's outgrown the space allotted to it. This cabbage leather has pretty much overgrown its environment, and it's time to cut it back (two photos below).

I'm fortunate because my coral grew on the substrate so I have no live rock to deal with (photo right). If your coral is attached to live rock, then you have two choices: 1) break up the rock (see this article for details) or, 2) slice it off the rock as shown in propagating the Nepthea above. In any case, you'll be slicing the live tissue with a sharp blade. I'm using a blade for a utility knife in these pictures. A single-edged razor blade or surgical scalpel will achieve the same result (photos below). Or, in difficult situations, a scissors may come in handy. I tend to use rubber bands to secure my fragments. It may be an overly simplistic method, but it's easy and cheap, and it works with most corals.

Realize that most corals have defense mechanisms that can include toxic or odiferous chemicals. Be sure to clean up thoroughly after fragging to prevent potential health problems. With even the best ventilation, the odors can be offensive, so be prepared to deal with that result.

Happy fragging, and be careful out there!

If you have any questions about this article, please visit my author forum on Reef Central.