Fish, Tanks and Ponds

Fish, Tanks and Ponds
A comprehensive guide to fish

Fragging Zoanthids


Button polyps (Zoanthus) are one of the hardiest coral that I have come across. They can tolerate fluctuations in water chemistry better then any other type of coral and are great for people just starting a reef tank. They multiply rapidly and quickly spread from rock to rock. The easiest way to get button frags is to place a rock beside the main colony and they will spread onto the new rock. Once enough buttons are on the new rock it is easy to cut the two rocks apart and you are done. But what if your colony is starting to move on to a rock you don't want it on or you want to split a colony you already have into a whole bunch of smaller colonies to sell later on? Here I have done just that. I have taken some of the buttons that are spreading around the tank and created three new colonies.

Fragging Station

Equipment Required:
Rubber Gloves
Rock rubble
Crazy glue (Super Glue UK)
1 Razor blade or very sharp scissors
paper towels
A container of clean saltwater to put the cutting in
A container of clean saltwater to hold the main colony

Base Rocks
Colony to be fragged

Here is the colony that I will be making the first cutting from. Some of the buttons are getting ready to grow onto a rock that I don't want them on, so I'm going to remove that part of the colony and glue it to a new rock.

drying base rock

Dry off the surface of the rock that you wish to place the new colony on in preparation for the glue. The glue will be added just after the colony has been cut away from the mother colony.

Inspecting colony

As you can see the buttons are already starting to grow onto another rock. When I try to lift the main colony up, there is a small piece of fleshy material connecting the colony together.

Cutting Colony

I cut the colony apart at the thinnest possible area attempting to do as little harm to the colony as possible. The small part of the colony that is left, is then peeled away from the rock to be prepared to be placed on the new rock.

Putting glue on base rock

Now that the fragged colony has been cut away from the rock, I add some glue to the rock it's going to be placed on.

Drying bottom of new colony for glue to set

Then I dry off the bottom of the colony so that it can sit in the glue and get the best hold possible.

New colony being placed on base rock

After the bottom of the colony is dried off, I position on the new rock it will call home. I let the glue set for about 20 seconds before putting it back in the water and rinse off any slime that comes from the colony. Here I'm using the knife to gently hold the colony on the rock while the glue sets. I didn't want to use my fingers for fear of squishing a polyp. I didn't use enough pressure to actually cut the colony but if it had then it would still be ok as long as both segments were glued down.

New colony just placed in tank

The colony was then placed back in the main tank where there is good lighting and good water flow.

New colony after 1 hour

This is the colony approximately one hour after the new colony was returned to the display tank. It's already beginning to open up, showing that they feel comfortable in the new location. I will continue to keep an eye on the colony to make sure it opens all the way.

New colony after 5 hours

This is the colony 5 hours after it's was put back into the tank. Most of the buttons in the colony have opened up. If the remaining buttons don't open up within 24 hours, I'll consider having to remove them so they don't rot and infect the healthy polyps within the colony.

new colony after 1.5 months

This is the same colony one and a half months after being fragged. They are well established and spreading across the rock. The rock has also matured and you see some different types of coralline algae's growing on it as well.

A note of caution:

Zoanthus contain a powerful neurotoxin that can be fatal if ingested. Make sure that you wear gloves when handling them and dispose of the gloves immediately after use. Keep your work area clean, and disinfect everything that is used afterwards. It's better to be safe than sorry.