Growth Rate of Zooanthid Polyps

In my years of observation of Zooanthid Polyps I have seen some grow at tremendous rates while others were lucky to add on a few button polyps per year. Seemingly with the same size stock and oral disc you would assume they could have come from relatively the same conditions and should respond in near the same manner. With Zooanthid to me this could not be further from the truth. Many of the color morphs looked identical but grew at totally different paces in the same conditions.

“ Perun's pink candies” featured in Sprung's Invert Guide
This Zooanthid color morph perhaps brought me the most attention when it had appeared in Julian Sprung's Invertebrates Guide. Julian had photographed the specimen in a visit to see my grow systems in April of last year. This specimen it is by far the most aggressive and rapid growing I have worked with to date. I have witnessed the colony quickly surround a Blue Acropora Abrolhensis and slowly killed off the tissue and begin encrusting on its base. The second most aggressive Zooanthid I keep are called “Actinic Yellow”. You can see in the photo they are growing right along side a piece of Heliopora. If you are familiar with this coral, it’s a quick growing mass that can cover most everything in the aquarium. The button polyps however, kept the colony of Heliopora’s growth in check along the side where the two meet. When the mouths would closed at various times you could actually see a series of half circles in the Heliopora that almost appear to be worn down from the Zooanthid polyps.

Zooanthid growth rates, information and guide