The Duncan corals are primarily from waters around Australia, and their dazzling large polyps, moving flawlessly in the water, instantly attract attention. The only challenge that a keeper faces is feeding Duncan because they eat a lot of food.

These are a type of LPS hard stone coral that quickly fills up the space provided they are placed perfectly. 

So, while artificial tanks are simple to set up, there are several critical points to remember in order to keep them safe and growing.

Those who want to have these lively creatures at home aquariums should read the Duncan coral care guide provided here. It includes all the essential information about their behavior, food, tank requirements, etc.

Characteristics Analysis: Duncan Coral

Species Details
Scientific Name Duncanopsammia Axifuga
General Names Whisker Coral, Duncanops Coral, Branched Disc Coral
Family Dendrophylliidae
Origination Australia, Philippines, South China Sea, Western Central Pacific.
Polyp Diameter 2-3 cm
Type Large Polyp Stony (LPS)
Color Light brown, green
Price in Dollars $20

Where do They Originate

The major areas to locate them are the Australian sea beds, which is why they are popular as Australian or Aussie Duncan corals.

These are easily seen with branches over the hard rocks and sands under the water. They mostly propagate 100 ft below sea level in clustered formations around the reef.

There are numerous colonies spread across Australia’s western Pacific region from South China sea to the Philippines.

What Do They Look Like?

The long glowing tentacles in light green, bluish, or brownish color are the first thing noticed on these reef species.

On top of the polyps, the shape is like a circular disk with a slight change in color from light to darkened, possessing striped lines.

They come under the LPS category, and thus possess a hard calcium carbonate skeleton. These corals are usually quite fleshy and have a thin structural profile.

Note: Tentacles surround the polyp mouth of Duncan coral, and often appear as of sea anemones. But its diametric size is not more than an inch and even shorter in length.

How big do They get?

It depends on the local environmental conditions for these corals to grow and increase in vertical length.

The Duncan corals in a home tank may have polyps of 1.5-2 cm. Under favorable conditions, they may grow three times this size, and continue to grow slowly.

The tentacles extend near the mouth of the polyps and may attain a size close to 2-2.5 cm.

What is Their Lifespan?

These are long-lasting species and have the tendency to live a centurion life. On an average, they complete about 50 to 60 years, but this is mostly observed in the deep-sea levels.

But while in an artificial environment, they have a very short life. Depending upon the care given to them as well as protection from infectious diseases, they might survive for close to a decade.

For a longer lifespan, expert advice to keep the Duncan in the low lying region of the tank; usually over a hard rock. This will help them spread over a wide area and form colonies.

How Much Do They Cost?

The Duncan corals are unique as they are the single species found in their genus. But the more intriguing fact is the danger to its existence.

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According to an IUCN report, the Duncan coral is a rare or threatened species.

Considering its vibrant beauty, market demand, and rarity, a single head of this coral is priced a bit high, ranging between $16 – $23.

The beginners show high interest in buying them as they are considered among the most convenient invertebrates to keep in tanks

Detailed Care Guide: Duncan Coral

Quick Lookout
Care Level Simple
Social Acceptance 
Predators No
Temperament Peaceful
Diet Photosynthetic
Propagation  Moderate

What are Their Feeding Habits

The Duncan corals are big-time eaters and attempt everything closer to their mouth. They also get the beneficial nutrients from photosynthetic activities due to zooxanthellae algae that live on their tissues.

Food consumption is done much like a hunter. The surrounding tentacles work to push the potential food particles inside the polyp’s mouth at the central disc.

They usually don’t make a choice in feeding and accept almost anything that is consumable. Some of the most suitable foods for Duncans are listed here.

  • Pellets
  • Phytoplankton and zooplankton
  • Cyclops
  • Daphnia
  • Krill
  • Calanus
  • Copepods
  • Mysis
  • Nauplii larvae
  • Reef roids
  • Brine shrimps
  • Chopped shellfish

Note: Since they cannot catch the food from a long distance. It is advised to feed them close to the mouth, but this should only be done 3-4 times a week.

Behavior and Temperament

The Duncan coral is a peaceful and harmless invertebrate, as it does not possess any dangerous extensions from its tentacles.

Nematocysts attached to it only produce a sticky substance on touching, but it does not sting other organisms.

The tentacles are often seen retreating back in bright light or when they sense danger, but otherwise they remain floating with the current.

It is due to the friendly nature of the Duncans that they attract high sales for reef tanks with other mates.

Note: If ample space is provided with sufficient food, they quickly start growing to form colonies of new extended branches, clustering close to the source.

What Do Duncan Coral Look Like

How do They Reproduce

Duncan coral quickly multiplies once it gets suitable conditions. Reef keepers rarely need to exert any effort to ensure natural propagation.

These creatures reproduce by forming branches from the polyp’s base and mature to become a family or colony of Duncans. This process never stops until the coral gets infected and dies.

Also read here about Algae that can multiply rapidly in a sudden algae bloom.

Mating Behavior

The Duncan coral is either gonochoric or hermaphroditic, which means it reproduces agamously. The gametes are spawned from the polyp’s mouth, and the zygote becomes a planktonic planula larva.

Soon the metamorphosis begins to form shapes like tentacles and pharynx. With the fragging method, it is possible to propagate them separately in another aquarium.

How to Frag Them

In the process, a sharp bone cutter or saw is utilized to cut a branch from the coral. Later, the trimmed branch can grow individually after it settles down well in a tank.

Certain precautions are necessary in the process, such as, maintaining the hygiene levels while cutting the polyp.

The tentacles retract once you start pricking because of their sensitivity, so do not worry about that. Separate the polyp close to the base, and keep it inside the water tank.

You can clean the damage with a medicated solution like iodine in a new tank. Now stick the single polyp on to a rock surface using glue.

Maintain water parameters similar to the parent tank and provide them with food. You may also feed them manually (close to the mouth) 4-5 times a day. It will start showing growth in a few weeks.

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Note: By feeding the best and nutritious items and providing a large space to spread, you may observe 5-6 new polyps sprouting in four weeks time.

Potential Health Problems Faced by Them

Though being easy to care for in water tanks, but there is always vulnerability to infectious health diseases. As an LPS category, they present a hard skin, but the fact is that it is sensitive and reacts quickly.

Some of the popular issues observed by researchers are discussed here.

  • Duncan Coral not opening: This is a common symptom seen in these invertebrates, but most of the time, there isn’t anything serious about it.

The Duncan corals often do not open for long, possibly because it takes time to adjust to the surroundings, or a new branch is about to sprout.

It is also possible that the coral is protecting itself from other tank mates that are intentionally irritating or touching it.

In the initial days after buying the coral, you must keep them in a quarantine dip to let them adapt to the environment.

Tip: You can also attempt to open the coral by offering food particles close to the mouth, but do not overdo this.

  • Bleaching: This situation often appears in bright light, high temperatures, or changes in water conditions. The coral gets stressed and shows a bleaching reaction.
  • Brown jelly: Duncans are easy to care for, but this does not mean they should be neglected altogether. Bad water quality, unnecessary food, or injuries by any means can form a brown jelly-like substance on its surface. It is contagious and spreads everywhere in a short time.

This condition must be treated soon, and for this, the infected branch must be plucked out and treated with iodine solution till it recovers, before placing it back into the tank.

  • Pests and diseases: There are some common problems faced by them, which include diseases caused by pests. It causes color fading, rough appearance, slime coat, or closed polyps. The ill-health might have persisted for a long time, and you can either treat them with an iodine solution or replace them completely.

Tank Arrangements: Duncan Coral

Quick Stats
Capacity 80 Litres
Water Temperature 75 to 82 F
Hardness Range 8 to 14 KH
Water pH Level 8 to 8.4
Gravity or salinity 1.023-1.025
Calcium 400-450 ppm
Magnesium 1250-1350 ppm
Nitrate 5-10 ppm
Phosphate <0.05 ppm
Ammonia 0 ppm
Tank Lighting Low to medium
Tank Type Community tank 
Tank water type Saltwater
Placement Hard rocks or sand preferable near the bottom
Water flow rate Slow to medium current

Optimum Tank Size Requirements

Duncan Coral shows a massive increase in its size, provided it gets enough space and nutrition. With that said, it is customary to arrange enough tank volume for them in which they gets completely immersed.

A typical aquarium with 18-20 gallons of water will create a good space for the Duncans to grow freely. If there are other reefs or the tank is crowded, then you must think about increasing the tank size soon.

Tank Setup

Duncan Coral is a simple, still, yet spreading species. It does not require much apart from a healthy environment. Let’s find out more about setting up the tank for this creature.


This is an essential part of keeping Duncan coral in reef aquariums. They need low to moderate lighting to thrive healthily.

These corals perform the photosynthetic process in light, but it is necessary to arrange controlled brightness in the tank.

LEDs, T5 fluorescent lights are the most suitable for them. It is even seen that they change color in specific light shades.

Substrate and Placement in the Tank

It is always recommended to place them on a hard rocky substrate, allowing them to grow nearest to the bottom or below the middle levels of the tank.

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You must place them where light is sufficiently focused for photosynthetic nutrition. Placing the Duncans vertically or horizontally hardly makes a difference, as they have a tendency to grow either way.

You can also add some amount of sand and other hard substances in the tank, which can help the coral spread over it.


Plants will not affect their growth unless it hampers the light or forms dark shadowson leafy branches. Therefore, you can avoid high-growing or floating plants.

Some plants that grow from the substrate may be suitable for them. A few are listed here.


Duncan coral hardly cares about any decorative items lying next to it. If it is a non-working model, the coral may cover it with branches in a short time. Working models may create irritation for some time.

Tank Equipment

In their natural environment, these corals face a moderate water flow rate and warmth. In such a situation, they show higher growth and form vibrant colors.

  • So, Duncan Coral needs water flow, but if it is higher than normal, their tentacles may get damaged. It is recommended to use wave makers or semi-water pumps to generate wave motion in the tank.
  • Using water filters will help enhance the quality and purity of tank water.
  • Since the suitable water condition is a tropical environment, it is best to use heaters to keep the temperature moderately warm, but under control.

Water Parameters

Any hobbyist or a beginner can plan to have the Duncan coral polyps in the home tanks. But to have them comfortably thrive in the given space, it is vital to maintain suitable water conditions in the tank.

  • Regular water change is the foremost requirement to maintain cleanliness through shuffling. The best option is to replace 20% water on a weekly basis.
  • The most effective water temperature is between 24-28 Degrees Celsius.
  • Water hardness should be between 8-12 KH.
  • The alkalinity level should be around 8-8.4 pH.
  • They need higher calcium due to the hard skeleton structure. Maintain the calcium level between 400-450 ppm.

Best Tank Mates

They look fantastic in fish tanks, and keepers purchase them because they grow fast and mimic a natural environment for marine life.

These are harmless creatures of the water because they do not sting. This feature makes them vulnerable to injuries from other organisms who chance to come closer or attack.

So, it is necessary to have detailed knowledge about what species can let them comfortably thrive in the tank. Here is a list of water inhabitants that are peaceful in nature, and do not intentionally scratch or disturb the Duncan coral.

  • Non-aggressive corals
  • Clownfish
  • Tangs
  • Cardinals
  • Damsel
  • Wrasses 

Frequently Asked Questions

Ques. What creatures should be avoided as their tank mates?

Ans. It is essential to be protective of these corals as they cannot defend themselves from danger. You must avoid inducing creatures with territorial behavior or aggressive nature.

Torch corals or other such types with stinging tendencies must be avoided. Shrimps, crabs, and other invertebrates must also not stay with them to protect them from potential damage and pincer attitude. Gobies and blennies are also not suitable.

Ques. Do clownfish host Duncan coral?

Ans. Clownfish are fond of moving and staying under the tentacle structures of anemones and corals. It helps the fish get protection or a hide out from predators.

In a similar manner, the Duncan corals are non-aggressive and friendly towards fishes once they adapt to their surroundings and stop closing.

The coral as a host provides a dwelling for the clownfish, while the fish offers nutrition to the coral in the form of faeces. It also cleans the unwanted algae from the surface.

Ques. Can Duncans sting other coral species?

Ans. They do possess nematocyst cells on the tentacles, but these cells do not have venomous excretion. Only a sticky jell is poked out when disturbed.

If tentacles from other corals pinch the Duncans, they will not defend or react in aggression. But on the other hand, the other coral, if aggressive in nature, may severely damage Duncan’s polyp or tentacles.

Final Thoughts: Should You Get Them in Home Tank

Duncan coral is more popular among new reef tank owners as it is easy to keep. It also enables us to learn the key factors in caring for these creatures.

They look cute and flamboyant with their changing colors, and they give a nice attractive texture to the aquarium’s appearance, while the tank mates find it a friendly shelter.

They can be a new addition to the tank with other corals, but the owner must arrange a separate and segregated space in the tank for them.

The Duncans grow faster in suitable conditions, but make sure to buy a healthy polyp with no injuries.

Read here –

About the Author

Victoria Lamb

Victoria is a freshwater aquatics specialist, fish keeper, and amphibian enthusiast. She has had more than 6 years of experience caring for aquariums and keeping several fish species, and her home boasts of 3 aquariums and a garden pond. Her goal is to educate fish owners on raising healthy and happy aquatic pets. Career Highlights:…

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