The “Fragging” Phenomenon


The tank at Penn State designed by Sanjay Joshi. This tank is filled with colonies that grew from fragments that Sanjay collected.

For anyone that has been in the reef keeping hobby for any length of time, the new found interest in coral cuttings, is rather amazing. The propagation of corals, especially stony corals, has been going on for at least the past fifteen years. However, the discussion, sale, trading and passion for coral fragments or “frags” is a rather recent phenomenon. Many of us that were involved in keeping these corals in the early 1990’s learned that it was possible to produce new stony coral colonies merely by breaking off a branch from a mother colony and attaching it to a substrate where it would encrust and eventually form a new colony. Much of this early experience was garnered as a result of the many problems that were initially encountered in trying to successfully keep stony corals, which at that time were much more difficult to keep than soft corals. As a result of these difficulties, colonies deteriorated or started dying after being kept in captivity for a period of time. When this was happening, especially with problems such as rapid tissue necrosis (RTN) or slow tissue necrosis (STN), some of the colonies appeared healthy while other portions were clearly in distress. To try and preserve the colony, the healthy portion of the colony or branches from this section of the colony were taken from the colony and placed on a piece of clean live rock or some other desirable substrate in the hope that they would attach. In these early days the outcome was pretty much hit or miss, as fragmenting sick colonies is by its very nature not a good place to start. Fortunately with experience and through the sharing of information proper fragmenting of corals is now relatively easy and in most cases successful.


Top view of that tank.

As the level of success has increased so too has the demand for fragments from rare, well-colored or unique corals. This demand for rare or brilliantly colored stony corals is at least partially due to the level of success in the hobby increasing dramatically in the last few years. Whereas ten years ago 90-95% of the hobby was focused solely on keeping saltwater fish exclusively, the evolution in the hobby that has taken place now shows that over 50% of marine hobbyists now keep some form of reef tank. In addition, while most reef hobbyists ten years ago kept mostly soft corals such as Sarcophytons, Xenia, and Sinularia, and a few stony corals such as Euphyllia and Plerogyra, today almost as many reef  keepers maintain stony coral tanks housing corals such as Acropora, Montipora and Pocillopora, to name just a few of the genera kept. The other reasons for this increased demand for fragments from propagated corals are a better understanding of the need to preserve the reefs as well as the fact that rare or beautifully colored corals are relatively rare on the reef. This last factor I observed first hand on a dive trip to Fiji, where the number of brown corals to colored corals was approximately 100:1 on the reef. By trading or purchasing propagated fragments, hobbyists now understand that not only are they putting less pressure on the reef, but they are also getting corals that have been shown to do well in captivity and keep the beautiful coloration that is so desirable.


There are also several other reasons for the increase in coral fragmenting. First it allows one to trade for other rare corals that otherwise one would not be likely to obtain. Second cultured coral fragments usually come from corals that have shown to do well in captivity. Third, cultured fragments usually have a lower likelihood of introducing diseases or pests than do wild colonies. And fourth even when fragments need to be purchased they are usually significantly less expensive than wild colonies.


This colony of emerald Stylophora was grown from a frag of less than 1″ from Leng Sy

One interesting result of this is that several dozen websites have popped up in the last couple of years specializing in either the trading or sale of coral fragments, with few to no wild colonies being available. As demand for some of these fragments far exceeds the availability the prices have increased as well. As a result, the price that some of these fragments are bringing in is quite amazing with some small ½”-3/4″ frags sometimes being sold for several hundred dollars apiece depending on their coloration and presumed rarity. Many of these entrepreneurs have a keen grasp of marketing techniques and have learned that giving a coral a catchy name or including the source of its origin can dramatically increase not only its cache, but also its price. Corals such as the Leng Sy cap (a purple rimmed green Montipora capricornis), Tyree purple Monster (a deep purple Acropora valida with a unique growth form) and the palettablue acro (a deep blue Acropora tenuis/pulchra) to name just three started this trend. Interestingly none of these individuals named the said type of coral after themselves.

The history behind the palettablue acropora is an example of how this phenomenon began. In the early1990’s, when keeping stony corals such as Acroporas was still relatively rare I was fortunate to be able to bring in several boxes of stony corals from Jakarta from time to time. For the most part, all of these corals were brown or beige, and if we were lucky some of them would have colored tips. When these corals came in, which was infrequent, I shared them among my friends and all of us more or less shared in the booty. As I said above, most of the corals we got were brown or beige with colored tips, so those went first. This coral when it came in was so dark brown that no one wanted it. Since I did not hold out much hope for this coral coloring up, and since we really did not understand the factors that would enhance a coral coloring up I kept this coral, which was more like a 4″ brown stick, and placed it at the bottom of my tank behind another coral, where I proceeded to forget about it. Nine months or so later, when I happened to move the coral in front of it, I was startled to find the most brilliantly colored blue coral I had ever seen. At that time, there were virtually no blue or other brightly colored corals coming in, so this one was indeed quite rare. As luck would have I was going to speak in Boise, Idaho for Sally Jo and Leroy Headlee at GARF and I promised to bring them out some coral fragments to trade. I had traded with them in the past, and the one thing I knew was that if I gave them a fragment they would not lose it, as they kept virtually everything they ever got alive. So as part of the package of fragments that I brought was a 1″ piece of this blue Acropora. We did not know the genus, as the colony was still so small that it was still relatively difficult to get a positive ID. Over the next year of so they grew out the fragment and started to sell of fragments of their own. Once people started seeing this blue Acropora word of mouth spread and people started asking for the blue Acropora. Since Leroy had no way of differentiating this from some of the other blue Acroporas he had at that time, he started calling it the palettablue acro, to separate it from the others he had. So this is how the name for this Acropora was established. The same thing has happened with dozens of corals since then and now that the demand for certain corals is increasing this practice. The intent of this practice now though is to raise the price for these interestingly named corals. Some of these new names include Alien eye Chalices, Superman Montipora, or Incredible Hulk Acropora. What is interesting about this practice is that many of these corals that demand a high price due to their unique or vivid coloration look very different when kept under different conditions and unless they are kept under optimum conditions they are just as likely to be brown as they are to have the vivid green cast of the hulk. The result of this may be that in the future, some corals may acquire different names depending upon who is keeping it and under what conditions.



Tools of the trade.

Proper Fragmenting Techniques

As mentioned above, in the past when corals were fragmented, successful outcomes were often more a function of luck than of skill. Now after many years of fragmenting corals, and knowing that fragmenting healthy colonies is far safer and more likely to be successful than fragmenting sick colonies, the success rate is much greater. In addition the techniques and necessary equipment have been standardized to be relatively simple and straight-forward. However, there is still some difference of opinion into the nuances of properly fragmenting corals for optimum health and growth of both the mother colony and the fragment. The first thing that is necessary is to have the proper tools. For stony corals the equipment is relatively easy to get and most hobbyists already have most of it. For cutting the corals, a sharp pair of wire cutters and needle nose pliers, are the best tools. The wire cutters are good for cutting thinly branched corals like most Montiporas, Acroporas, Seriatoporas and Stylophoras and any of the thin plating corals like Echinophyllias and Oxyporas. The pliers are useful for fragmenting thick bulky corals like Pocilloporas, Acroporas humilus, etc. In addition to these tools, several pairs of tweezers are useful including a pair that is very long. Long tweezers are useful in that invariably a fragment will fall in between the rocks where it will be difficult to retrieve without tearing down a lot of live rock so having a pair of these will come in handy. Several adhesives that can be used in saltwater are also imperative to have on hand. The best of these are gel type superglues and waterproof epoxy. In addition to the adhesives, a substrate of some type such as pieces of clean live rock, plastic florists’ plugs or cured homemade cement plugs will be useful to attach the fragments to. Lastly brushes with which to keep the substrate clean and free of algae around the fragment are essential for the growth of the fragment. Hard toothbrushes as well as brushes for detailing a car are very good for this purpose.


Frags being acclimated in mesh basket.


The desired mother colony for fragmenting should be selected that is healthy and growing. Many of us learned to fragment corals when colonies were dying and fragging them was the only means for keeping even a small portion of them alive. However as we have gained experience we have learned that taking fragments from healthy colonies produces fragments that have a much higher likelihood of succeeding. Once the colony has been selected, the branch on the colony should be chosen for removal. Usually this branch will be on the lower portion of the back or side. These branches are chosen as their removal will not detract from the beauty of the colony. The branch selected should be snapped off as cleanly as possible with the wire cutters or the needle-nose pliers. The goal is to snap it off in one quick motion rather than to cut or smash the tissue on either the fragment or the mother colony. When this is done properly and cleanly there is little likelihood of infection to the mother colony or the fragment. In some of the colonies that I have fragmented I have seen some of the mother colonies grow faster after being fragmented than I had observed when I had left them alone. The fragments themselves should be as large as possible at least 1″ in size. The larger the coral fragment, the greater the likelihood that it will do well over time. I have purchased and traded fragments that came to me at less than ½” in size. These fragments have traditionally done much worse than the fragments I received that were 1″ in size or larger. These smaller fragments are harder to work with, fall and get lost easier, are more sensitive to changes in water quality and take much longer to grow to a reasonable size than do larger fragments. That is why when trading or purchasing fragments you should know in advance the size of the fragments you are getting so as not to be disappointed. However, for rarer corals where demand far exceeds supply the only opportunity to obtain these corals my be a willingness to accept a smaller fragment.

Regardless of the size of the fragment obtained the handling of them should be the same. First it has been my experience that newly obtained un-mounted fragments should be given a couple of days to recuperate after shipping before being mounted in a new tank. To allow these corals to recuperate I place all new fragments in a perforated box that allows for strong flow to move across them. These boxes are easily obtained at pond supply stores. In addition to good flow the corals are exposed to moderate light. The corals are never placed under strong intense light after their arrival is this is likely to lead to their bleaching out. The box holding them is placed off to the side away from intense light and egg crate is placed over the box to further shield the fragments.

After two or three days and after they are observed extending their polyps the corals are mounted. Initially most hobbyists mount fragments so that the cut portion of the fragment is attached to the substrate and the branch tip is face up as this looks like how the mother colony is growing. Unfortunately this is not the optimum way for getting a fragment to grow. After observing the growth of several fragments that I had inadvertently knocked off while working in the tank it was apparent that when a fragment falls in the wild it does not fall broken end down, but rather the entire branch falls flat against the substrate. As a result of this observation I conducted an experiment where I mounted three fragments from the same mother colony differently. One was mounted in the traditional manner, one was mounted lying on its side as I had observed to occur naturally, and one was mounted with the growth tip down, as the growth tip is where the most rapid growth is occurring in the colony. After one month and two months the differences in growth was significantly different. The colony that had been mounted in the traditional way had encrusted around its base as was normally the case. However the fragment mounted on its side encrusted along the entire fragment, producing a much larger area from which to grow. The fragment ant mounted growth tip down had encrusted very little. As a result of this experiment, I now mount all fragments so that most of the fragment is touching the substrate with only the portion of the fragment that was broken off not touching the substrate. This is done to allow the cut portion to heal away from the substrate where bacteria are more likely to be present and where this cut tissue is a more likely point of entry for bacteria and other pathogens.

The best means for mounting a fragment is to attach it to its desired location either with any of the gel-type superglues on the market or with some of the waterproof epoxies. Regardless of which media is chosen the key thing to keep in mind is to use an adequate amount of the adhesive. The fragment can be mounted either to a location in the tank, in which case the desired location should be considered permanent, or on to a small piece or live or similar substrate. This latter method should be chosen if the eventual permanent location has not been decided on or if it is easier to keep track of the fragment by having it on a small piece of substrate.


A section of the author’s tank where frags are allowed to grow together.

To attach the fragment it should be removed from the water, and the portion of the fragment to which the adhesive will be attached should be gently blotted dry with a terrycloth or similar towel. Drying the fragment is crucial as none of the adhesives adhere very well to wet surfaces. If superglue is being used, an adequate amount should be applied to the fragment, the amount should be enough that some of the glue should extend beyond the sides of the fragment. The fragment with the bead of glue should be held out of the water for an additional 30 seconds to allow for an air bead to form on the surface of the glue. This air bead will allow the glue to be moved underwater without dispersing. The fragment can then be moved underwater to its desired location and gently mounted into place. The fragment should be held in place for an additional 60 seconds. This will give the glue time to adhere and the coral should then hold into place. During this process the water motion within the tank may be shut off and remain off for 5-10 minutes. This will prevent the newly attached fragment from being moved immediately after it has been attached. After this time, everything can be run normally. This same procedure should also be followed when epoxy is used. One other thing that should be noted during this mounting process is that while mounting the fragment the polyps and tissue should be touched as little as possible and extreme care should be taken not to smash any of the polyps on the fragment. Smashed polyps are much more likely to become a source of infection than are intact polyps. If the fragment is mounted on a small piece of moveable substrate then it should be mounted in a similar fashion and the substrate and fragment can be allowed to “cure” for 30 minutes or more in a bucket or other receptacle outside of the tank. This outside curing increases the likelihood that the fragment will be attached firmly before being placed in the tank. Once this is done the piece of substrate can then be placed on mounted into the desired location within the tank. If the initial location proves undesirable it can readily be moved to another location. Signs of an undesirable location would be limited or no polyp extension within 24-48 hours, tissue sloughing, bleaching or limited or no encrusting by the fragment onto the substrate after a month in the same location. Lastly it should be noted that even the best adhesive will not keep a  coral fragment mounted forever. The goal of the adhesive is to keep the fragment in place until it lays down enough tissue to keep it in place. Under good conditions an adequate amount of tissue should be laid down within 30-45 days. IF after this time period the fragment is still become dislodged, then the conditions within the tank should be checked to make sure adequate calcium, buffer and magnesium are present to allow the fragments to grow.


A blue Acropora millepora showing with the white areas showing where fragments have been taken.

Frag tanks

The fragmenting of corals has become so widespread that many hobbyists now have a separate tank to house and grow coral fragments. This type of tank allows the luxury of being able to grow out even the smallest fragments without having to worry about them disappearing by falling into the live rock or having a predator wipe out a small fragment with one bite because the fragments are out in the open and hence more conspicuous and not overwhelmed by full-grown colonies. A special frag tank allows for even the smallest fragments to be nurtured and cared for more easily due to their being able to be seen and noticed. This is important as the single biggest reason for a fragment to fail to reach an adequate size is it falling off of the mounting and being lost. For this reason, most frag tanks should be bare-bottomed as it allows for fallen fragments to be more easily seen. It is also easier to catalog and keep track of the fragments in these tanks if digital pictures are taken whenever new fragments are added or removed. By taking pictures and comparing the picture with what is present it is easy to determine if something has happened to a fragment. A by-product of taking pictures on a regular basis is that it also allows for growth of the fragments to be more readily assessed. In this regard it can be determined if the growth of the corals is constant and if it is not to start looking at wheat factors have retarded growth or accelerated it. It also allows for the growth rates of different corals to be compared. This is important if one is looking to “farm” corals for sale in that it is usually desirable to try and farm faster growing species over slower one.



Two blue coral fragments two months after being mounted on their sides.

A fragment tank does not need to be anything special, nor even particularly large. It can be a tank that is separate from the main display tank that runs on its own, or usually it is simply a small secondary tank that is attached to the main tank. In fact many hobbyists are now using their sumps or parts of their sumps as frag tanks. By having the frag tank attached to main tank it allows the coral fragments to be in the same water conditions that the show colonies are. As a result their water has optimal nutrients as well as the proper temperature, calcium and alkalinity. The only two factors that usually need to be added to maximize the growth of the fragments are lighting and water movement. Both of these are rather easy tomaximize with small powerheads and small lighting fixtures. Using small units to supply these needs is possible owing to the small size of the tank housing the fragments. As mentioned above, some hobbyists are now using their sumps to grow out coral fragments. Some have even taken this one step further and have set up larger and larger sumps attached to their main display tank in order to grow out large numbers of coral fragments. These additional sumps need not be anything special all they really need to do is be able to hold water. Large plastic troughs or plastic basins are perfect for this job and are easily drilled, which also allows for their plumbing to be rather simple as well. These additional sumps actually help the overall health of the display tank in that they can dramatically increase the overall volume of the tank while only minimally increasing the biological load.


Close up of same two fragments.


Frag swaps

An interesting result of having so many hobbyists fragmenting their corals and always wanting to add more and different species to the collections is the advent of the frag swap. Just as collectors of rare items have done for a long time, hobbyists have found that getting together with others that share their passion, some would say obsession, allows them to readily and sometimes inexpensively add to their collections via a frag swap. Usually these swaps are advertised by a local club or via the internet and hobbyists from all over the neighboring geography come and bring along fragments of corals from their tanks. These swaps have become so popular that some of them have induced hundreds of hobbyists to attend.


Same two frags 4 months later.

Initially these swaps were somewhat random unorganized events where most hobbyists brought frags from corals that were overgrowing their tanks while only a few hobbyists brought a couple of rare choice fragments. As a result, the hobbyist with eh choice fragments was overwhelmed while the common stuff often went unclaimed, which frustrated the individuals that had brought them. Fortunately as the swaps have evolved, the organizing to set them up has improved as well. Due to internet and club forums and bulletin boards hobbyists attending swaps can now post what they plan on bringing and ascertain the level of interest before they bring it and thus bring more or less of the frags they have according to the level of interest. Some hobbyists now go so far as to set up specific trades before they go with other hobbyists to make things go more smoothly. In the best conceived of these swaps hierarchies are set up that allow individuals with the most desirable frags to get first choice of the other most desirable frags. This new twist increases the likelihood of rarer and better frags being present and this increases the attendance even further. Since many of these hobbyists are far enough away from each other that they are unlikely to see each others colonies or frags, many hobbyists now go so far as to post digital pictures of their corals and fragments to give hobbyists attending the swap an even better idea of what may be available. The more information that can be provided before a swap the more likely it is to be successful.

If a new hobbyist wishes to attend one of these all they need to do is go on the many reef based message boards or contact their local aquarium club or society and see if any swaps are occurring locally. Even if one does not have anything to trade, many of these swaps allow for fragments to be sold, usually at very reasonable prices. The swaps provide many benefits to the hobby. They allow for rare and even common corals to be disseminated to more and more hobbyists without the need for corals to be removed from the reef. Just as importantly, many of the hobbyists attending these meets readily provide useful information about what they are doing in a non-threatening fun forum where they are less likely to be flamed or criticized for expressing their opinion. As a result the success of these frag swaps is further increasing the overall success within the hobby in general. Lastly they also provide another fun aspect to the hobby by allowing like-minded individuals to get together.


As the hobby continues to expand it is becoming more andmore likely that eventually restrictions will be placed on the harvesting of corals from the reef. Fortunately the increased success in keeping of all corals over the past decade is allowing more and more propagating of these corals to take place away from the sea. As a result, even if the harvesting of corals from the sea were to take place it is highly unlikely that this would dramatically diminish the availability of beautiful corals over time. In fact, it might even increase the level of success as only those corals that had shown to be tolerant of captive conditions would be available. Just as “Stuber’s acropora” has been propagated and is now in literally hundreds of tanks they same may become true for many of the corals we are now propagating within or own tanks now.

  Advanced Aquarist, Advanced Aquarist

 Mike Paletta

  (3 articles)

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