Dave here. Coral propagation, or fragging as we reef geeks refer to it, is the process of creating new coral colonies from a parent colony. Over the last several years, techniques, products, and general knowledge of the practice rapidly evolved to where it is quite common. As little as five years ago it was something new and exciting, or even scary depending upon your perspective. The thought of cutting pieces off of your prized coral colonies may seem intimidating at first, but it is actually quite safe, and the fragment has an excellent chance of survival if properly handled. Some corals are more easily fragged, and are better suited for the beginner, than others.
These types are what I will focus on for this blog. In general branching stony corals, and Zoo polyps, are among the easiest and most desired corals to frag. If you look around for your local reef or aquarium clubs, many of them will have frag swap meets, so that hobbyists can sell and trade frags with other hobbyists. It is a really great way to promote coral conservation: the more fragged corals you keep, the fewer corals need to be collected from the reefs. Frag swapping is also a great way to share knowledge, and increase survivability of captive corals. Propagated corals are hardier, and often more colorful, than wild corals. They have been raised in artificial conditions, and will usually keep their color. Wild corals can change color dramatically when adjusting to captive conditions.
There are a few basic items that you will need in order to start coral fragging. First, you need a suitable coral (Duh!). You should try to use only healthy coral colonies for fragging, as it will increase the survivability of both the parent and the cutting. While much fragging is done with damaged or dying corals in an attempt to save something, this is a much less successful way to produce coral frags, and should only be done as a last resort for the specimen. Fragging healthy corals will lead to a much better result.
Second, you will need something to mount the coral to, and there are several options here. Live rock rubble makes excellent, natural looking frags, but can be difficult to get in volume, and can be difficult to keep stable while the frag is securing itself. Commercially available Plugs and Disks, while less attractive initially, allow for quick and easy attaching. Using Plugs and Disks will also allow for easy volume production, as they will either fit snugly into egg crate material, or flat surfaces, so that you can grow out many frags, securely, in a small area. While we are on the subject of eggcrate, for those of you unfamiliar with the material, this can be found any home improvement center in the lighting section. Eggcrate can easily be cut and built into shelves and platforms to mount your frags for establishment and growth.
Next, you will need glue for attaching your cuttings to your rubble, plug, or disk. “Super Glue”,or Cyanoacrylate Gel is the glue of choice. This glue is harmless to the coral, dries quickly, and is easy to use. The glue is available in clear and pink colors, as well as different thicknesses for the job at hand. Your other choice is epoxy putty, this works well for some stony corals, and is well suited for use on rubble rock. Epoxy Putty is also available in several colors.
Finally, you will need cutting tools. Several types of cutters, scalpels, and snips are available on the market. Depending upon the type of coral being cut, different tools will work best, so it is best to have an assortment of tools, or even a kit at your disposal. What you may like to use may not be what I like to use, but if it suits your purposes, go for it. In general snips, shears, and cutters should be used on branching stony corals, and scalpels, razors, or chisels work best for Zooanthid polyps and encrusting corals.
You should strongly consider using safety goggles and rubber gloves, as many of the secretions and fluids that are produced when cutting corals can be very irritating, and even dangerous, to your skin and eyes. Protection is very important.
Once you have all the tools you need, the fragging process is easy. For stony coral, it is as simple as cutting the tips off of one or more of the branches of your parent colony and gluing the freshly cut tip to your plug or piece of rubble. Don’t be shy about the amount of glue that you use, you want to make sure that it stays attached so it can grow onto the plug. You can remove the coral from the water to perform this step. The parent colony will heal over and grow a new tip, or tips. The freshly attached frag will, over a period of weeks or months depending on species, grow over the glue and firmly attach to the plug.
Zoo Polyps can be removed from a parent colony by carefully removing them from the rock they are attached to with a scalpel or sharp chisel. Just a few full polyps are all that you need to start a new colony. With each removed polyp, a new frag colony can be started. Attach the cut polyp to a disk or piece of rubble rock, and then the polyp will attach and multiply on its own. Just as with the stony coral frag, the zoo polyp frag will grow over the glue and cover the disk or rock over a period of weeks to months.
This process can be repeated over and over, allowing you to produce many frags over time. Most people will choose to do this with just a few corals, and use these new frags to trade or sell for different species for their displays.
This covers the basic concepts behind coral propagation, for more detailed information on the subject there are a lot of great websites available. One of my favorite references on the subject is Anthony Calfo’s “Book of Coral Propagation”. Anthony has given several demonstrations and seminars on the subject here at TFP, and has a wealth of knowledge on the subject.
Until next blog