Zoanthus Coral Care


Yellow Polyps are are a close relative of Zoanthus and Palythoa from the Genus Parazoanthus. There are several species of Parazoanthus in the wild, but the most commonly seen species in the reef aquarium hobby are the bright yellow Parazoanthus gracilis.

Their color is the standout feature of yellow polyps. Bright yellow coloration is one of the more difficult colors to come across in reef keeping. Much of the time, it is associated with challenging non-photosynthetic corals such as sun corals or non-photosynthetic gorgonians. Occasionally you will find yellow highlights in corals such as Zoanthids or some LPS such as Scolymia, but rarely would one find a predominantly bright yellow variety of any of these.

The only few non-photosynthetic corals that are solid yellow that I can think of are, Yellow Fiji Leather, Yellow Scroll Corals, and Yellow Porites. That's about it.

Anyway, without further ado, let’s jump right into the care tips for yellow polyps.


First off, let’s cover Lighting. Parazoanthus are not necessarily light demanding, but lighting makes a profound difference on both the color development of yellow polyps and their aesthetic presentation in the aquarium.

What do I mean by that? These polyps are photosynthetic and can grow and be healthy in just about any kind of light. What I have noticed though is their color and size changes dramatically depending on the intensity of light.

When provided low light, say 50 PAR and under, the polyps take on a mustard yellow color and the polyp itself grows in size with fuller polyp extension.

Under more intense lighting over 150 PAR, the polyps develop a canary yellow color and shrink down to a quarter of their original size.

Light also plays a big role in our viewing of them in the aquarium. In this day and age, reef hobbyists tend to go much heavier into the actinic range. This should come as no surprise because actinic light shows off the incredible fluorescence of a multitude of corals. Doing that with yellow polyps however will be highly disappointing as they are essentially non-fluorescent and all of their bright yellow color will be lost in favor of a muted grey blue color. To appreciate the full intense yellow coloration of these polyps, you will need to provide daylight coloration between 6,500 and 10,000 Kelvin.

Low Light

Low light translates to about 30-50 PAR

Medium Light

Medium Light is between 50-150 PAR

High Light

High Light is anything over 150 PAR

Lighting is a loaded topic, so for a more in-depth discussion of lighting, please see our Deep Dive article.


As for Flow requirements, these polyps tend to do best in medium to high flow. The increased flow helps prevent detritus from settling around the base of the individual polyps as well as increasing their feeding opportunities.


Speaking of feeding, you really do not need to go out of your way to spot feed this coral because they are some of the most capable corals when it comes to prey capture. Their tentacles are highly effective at grabbing food out of the water column and the very act of feeding your tank will provide plenty of opportunities for yellow polyps to grab what they need. I’ve seen them grab up both dry food as well as frozen food and they can ingest anything up to a mysis shrimp in size.

One downside to the effectiveness and activity of their tentacles is aggression towards neighboring corals. Long story short, yellow polyps are highly effective combatants and will likely win a stinging contest against most other corals. For this reason placement is very important. I recommend keeping them on an island to themselves. They are a relatively fast multiplying polyp and if they share a rock with other corals, there is a risk that they will overtake the others with their growth rate and aggressive nature.


That pretty much does it for this short blog on Parazoanthus. If these seem like a coral you would enjoy having in your tank check out our Parazoanthus page on this website.

Until next time, happy reefing.

Than Thein