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Please note:This article and pictures were taken from my website and was written by Stephanie Abbott, if you wish to use this article please message me for prior permission.

Scientific Name
Zoanthus sp.
Common Name
Where does it come from?
Various Places

***WARNING***: Zoanthids and related corals, excrete a powerful toxin known as "palytoxin". Palytoxin is one of the most toxic substances known. In order to protect yourself, gloves should always be worn when handling these corals and hands washed afterwards. Avoid handling if possible, if you have any cuts on your hands or arms. Special precautions should be taken when fragging (read below for more info).

This is very serious, as palytoxin is more than capable of killing a person if no treatment is received. Symptoms of poisoning include: a metallic taste in the mouth, nausea, rapid breathing,breathing difficulty, chest pains, muscle spasms & convulsions. It has a very rapid progression, and symptoms can start within minutes to hours of the palytoxin entering your body. Hospital treatment is urgent and doctors/nurses should be directly told about the possibility of the toxin.

Coming in every color and combination imaginable, zoanthids (with given nicknames "zoas" or "zoos") are a very common but beautiful animal. These corals are very easy to take care of, making them an ideal choice for beginning reefers. With affectionate names for certain color combinations like, "Purple People Eaters" and "Radioactive Dragon Eyes", who wouldn't love these corals?


Zoas grow in a mat-like pattern, with individual polyps growing on top and generally connected together by the mat. Each individual polyp has namely three different parts to it. The middle of the polyp is a circular mouth, and encircling that is the oral disk. The tentacles surrounding the disk are generally referred to as the skirt. Each separate section of the polyp may have completely different coloring. Deepwater zoas are generally known for having some of the most explosive colors.

Behavior: Zoas are considered fairly peaceful corals, and can generally be placed very closely next to other corals without any problems. That being said, they DO have the potential to sting and be stung, so some room should be given. Because of their fast growth, they can also very easily start to grow over other corals, causing the corals underneath to die. Placing different kinds of zoas next to each other in order to get them to grow together, is perfectly acceptable and they will not harm one another.

Lighting & Feeding: Not very picky, they can tolerate a wide range of lighting conditions, placing them in the low lighting (what does this mean?) category. Although survivable, very low lighting will greatly decrease growth and may fade colors slightly. Colors may also begin to bleach if too high of lighting is used. In the case of metal halides, zoas should be placed very low in the rockwork to maintain strong color. These corals are mainly photosynthetic and do not require supplemental feeding, however, it will increase growth. Recommended foods include: phytoplanktons, small zooplanktons (such as rotifers or brine shrimp), Oyster Feast, small pellets etc. In order to feed, simply target feed polyps with chosen food and either spray or drop food over the polyps. In response to feeding, individual polyps should close over the food in order to digest it.

Flow & Placement: Low to moderate, gentle & indirect flow is best suitable for zoas. It should be just enough so you can see the polyps slightly moving. Supplements: Being soft corals, zoas do not require special supplements. Regular water changes to the system should be adequate.

Growth: Individual zoa polyps generally all grow from a mat attached to the rock, which connects all of the polyps together. New polyps will "sprout" up from this mat, staring small, and eventually growing to the size of the rest of the polyps.

Fragging: Zoas getting out of control? Fragging is very simple. As stated above, ALWAYS WEAR GLOVES AND EYE PROTECTION when fragging zoas. When cutting, the polyps tend to squirt a liquid and you don't want that in your eye! Groups of polyps can be fragged by cutting the section of the base they are on and peeling it away from the rock, or individual polyps can be fragged in a similar way. All cutting should be done in swift, clean cuts (suggested equipment includes a sharp raiser, such as an x-acto knife). Those polyps can then be superglued or epoxyed onto a new rock. Appropriate amounts of iodine may be added to help the coral to heal. ***WASH ALL EQUIPMENT AND HANDS VERY WELL WHEN FINISHED***

Common Ailments: There are several pests which specifically target zoas. ***WARNING: NEVER remove zoa pest with bare hands... Since they eat zoas, they also have the potential to poison you with palytoxins***

Sundial snails

Symptoms - Zoa polyps disappearing and remaining polyps staying closed
Remedy - Examine rocks closely for the snails. Many times they will be "resting" during the daytime at the base of the rock or conversely, at night they will be roaming around eating all your lovely polyps. Physical removal is best. Continue to check afterwards to ensure no cute little babies have hatched.

Zoanthid Eating Nudibranches

Symptoms - Zoa polyps disappearing and remaining polyps staying
Remedy - These are tiny and very difficult to spot. The best way to remove is by using a coral dip. The dip will not affect eggs, and so repeated dipping will likely be necessary as the eggs begin to hatch. The eggs will generally be laid within the polyps, and appear as small, white spheres.

Zoa Spiders

Symptoms - Zoa polyps disappearing and remaining polyps staying closed
Remedy - Difficult to spot. Coral should be dipped to remove and may need to be done multiple times.

Zoa Pox

Symptoms - Closed Polyps covering in small white bumps
Remedy - Unfortunately, there is no absolute remedy for pox. Possible treatments include: Using a coral dip, dipping freshwater and dipping in Lugol's iodine.


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