Reef Aquarium Coral Types

Polyps and Zoanthid Corals

Zoanthids (commonly referred to as button polyps, zoos or zoas) are great for the novice reef aquarium hobbyist. These corals are very hardy and can flourish in a variety of aquarium conditions. Ranging from dull browns to electric blues, zoos make a great aesthetic addition to any aquarium. They have the desirable trait of being able top spread over large areas, covering empty spots in the tank; they have even been known to spread to equipment like power heads, overflows and other unattractive equipment.

Zoos require moderate lighting. In heavily lighted aquariums, they will need to be placed near the bottom half of the aquarium. Also important, zoos require light to moderate flow to capture food and absorb essential elements from the water. These corals use zooxanthellae for photosynthesis but will take solid food if it is present.

Propagation of zoos occurs by budding. New polyps often stay attached to the mother and, thus, form a large colony that covers whatever they are on. Zoos are an invasive species and will grow onto anything that is placed next to them, including aquarium equipment and other corals. Be attentive when placing them as you don’t want them to cover up any specimen corals you want displayed. An easy way to keep zoos from spreading everywhere is to place the colony on your sand bed. It has been observed that placing colonies on the sand bed will keep them on their original rocks as they do not like to move directly onto sand. If you have a large colony that is spreading onto other coral, you can use a razorblade to cut the zoanthids away from the coral in question. You can then use the separated pieces as new frags. You can then trade these frags to a friend or sell them back to the local fish store (LFS).