Plate Coral, Heliofungia actiniformis, also known as Long Tentacle Plate Coral, Sunflower Coral, and Disk Coral
Heliofungia actiniformis

The Plate Coral, or Long Tentacle Plate Coral, has the largest polyps of all the corals!

The Plate Coral Heliofungia actiniformis is the only member of its genus. It was formerly considered to be a subspecies of the Fungia genus as their skeletons only differ in detail. This was the case until coral biologists became aware of the differing sizes and shapes of the polyps. The Heliofungia coral has the largest polyps of all the stony corals. Both of these large polyp stony (LPS) corals are found in the same types of habitats though the range of H. actiniformis may be a little more restricted. On the reef these corals generally inhabit shallow areas in calm lagoons on sandy or muddy bottoms.

The Plate Coral is also called the Long Tentacle Plate Coral. It has a round disk shape like the Disk CoralFungia sp., yet it is easily distinguised by its large, long tentacles topped with knobby tips. They are usually brown or olive with white tips, but sometimes are bright green, dark purple, or yellow. Pink tips and solid pink tentacles are also common.

These corals are absolutely beautiful, but with their long flowing tentacles they are often mistaken for anemones. In some instances they have the exact same color and can look like a miniature Magnificent Sea AnemoneHeteractis Magnifica when they are mature. They also have curiously similar characteristics as several Euphyllia species, especially when young and still connected to rock work.

In the wild, H. actiniformis normally sits on soft, flat substrates, but they have also been found on rubble. They have the ability to “unbury” themselves in the substrate and right themselves if they are overturned. They do this by filling their tissue with large amounts of water, thus becoming more buoyant. They can then use the water current as their mode of transportation. In the aquarium them may also move about the substrate and so may need to be “boxed in” with rock formations.

The Long Tentacle Plate Coral is somewhat more delicate than the Fungia genus, and so is somewhat harder to care for. Low to moderate water movement is needed and it requires medium to strong light. This coral sends out sweeper tentacles and so should be given a good 6 inches of clearance all around.

H. actiniformis are readily available, so beginners often pick them up, although they generally should be kept by a bit more experienced reef keeper. Usually these corals do fine for some time but then can suddenly die, often for no apparent reason. Once cause of their demise is aquarists placing them on the rock work. This results in falls and/or causes tissue laceration, infection, and death. Another problem is with not feeding them enough, they must be fed daily to thrive in the aquarium.

Long Tentacle Plate Coral, Heliofungia actiniformis hosting clownfish

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Size matters

Your Long Tentacle Plate Coral should be quite large before attempting to let them host a clownfish. Your clownfish should be a “gentler” species that does not get very large, like a Percula, for example. Reaching 8,” your tank needs open substrate for them to wander around. Other corals, whether they are weak and will be harmed or stronger and will kill, need to be at least 7″ above the substrate so the tentacles cannot reach or be stung. Feeding daily and keeping the substrate free of other corals is best. Provide at least 50 gallons and spaces between rock should be ZERO or 9″ or more.

Scientific name

Family: Fungiidae
Species: Heliofungia actiniformis

Distribution / Background

Heliofungia Coral Information: The Heliofungia genus was described by Wells in 1966. The Plate Coral Heliofungia actiniformis was described by Quoy and Gaimard in 1833. This is the only valid species in the genus. Some common names these corals are know for are Plate Coral, Long Tentacle Plate Coral, Disk Coral, Mushroom Coral, and Sunflower Coral. The Heliofungia coral has been propagated in captivity.

Where Heliofungia Corals Are Found: H. actiniformis are found in the Indian Ocean, from India to the Tropical Western Pacific, then from Australia, on the Great Barrier Reef, south to Admiralty Gulf on the west coast, then north to the Ryukyu Islands.

Heliofungia Coral Habitat: The H. actiniformis are found on soft, flat substrates, but have also been found on rubble. They are typically found in reef lagoons, in shallow waters to depths up to 131 feet (40 m). When they get sediment on them, they have the ability to “unbury” themselves in the substrate. They can also right themselves if they are overturned. This is done by filling their tissue with large amount of water, thus becoming more buoyant, and then using the water current as their mode of transportation.


The H. actiniformis is on the IUCN Red List of Endangered Species listed as Vulnerable (VU).


Picture of a Plate Coral

What do Heliofungia Corals look like: The Plate Coral H. actiniformis is a free-living polyp whose tentacles are so long they hide their skeletal structure. They can be mistaken as an anemone at first glance. Their shape can be oval or round, and with or without an arch in the middle. They can get up to 8″ (20 cm) across, and the mouth can be 1″ (3 cm) wide. Lifespan is unknown.

The Long Tentacle Plate Coral is not quite as colorful as the Fungia genus. They all have striped oral discs or mouths. Their base color can be olive, brown, dark purple, yellow, or green with tentacles that have contrasting tips that are white, pink, yellow, grayish violet, green or white.

Difficulty of Care

Heliofungia Coral Care: The H. actiniformis can be moderate to care for. They need to have proper placement, proper lighting, and regular daily feeding. They are also much more sensitive to other corals stinging them and are more prone to tissue laceration and infection than the similar Fungia genus.

Foods / Feeding

Heliofungia Coral Feeding: The Heliofungia corals, like other large polyp stony (LPS) corals, have developed several feeding strategies. Through a symbiotic relationship with a marine algae, known as zooxanthellae, they receive many of their nutrients. They also capture planktonic organisms, food particles from the water column, and can absorb dissolved organic matter.

In captivity, these corals need to be fed at least daily, in fact they possibly need to eat even more than the Fungia genus. They can be fed shredded meat, including mysis. With larger foods, try to feed the whole organism to the coral. For instance if you are feeding it a silverside, chop it up but feed it all, so your Plate Coral will get the fullest nutritious benefit from the meal.

Aquarium Care

Typical water changes of 20% a month, 10% biweekly, or 5% weekly are needed. It has been noted that 5% weekly water changes replenish many of the needed additives and it is ultimately cheaper than purchasing additives for the water. With higher concentrations of coral with calcareous skeletons though, there may be a need put in additional additives to maintain proper levels for good growth.

The following water supplements are suggested for Heliofungia species:

  • Calcium: 400 to 450 ppm. If a large poly stony (LPS) coral does not have enough calcium, it will not grow. (Seachem makes a calcium additive that states 385 as sufficient)
  • Alkalinity: 3.5 TO 4 MEQ/L (8 to 11 dKh, 10 is recommended)
  • Phosphates: 0, zero. Phosphates are the worst of all and all corals hate them.
  • Magnesium: 1200 – 1350. Magnesium makes calcium available, so if your calcium is low, check your magnesium levels before adding any more calcium.
  • Strontium: 8 – 10

Aquarium Parameters

A well-feed live rock/reef environment is what is needed for your Plate Coral, along with some fish for organic matter production. Have an open area of soft substrate or a rubble bottom for this animal.

Quick Reference Chart
Lighting:Prefers Low Lighting LevelsPrefers Medium Lighting LevelsPrefers High Lighting Levels
Water Flow:Prefers Low Water Flow LevelsPrefers Medium Water Flow LevelsPrefers High Water Flow Levels
Temperament:Peaceful TemperamentSemi-Aggressive TemperamentAggressive Temperament

Provide a low to moderate water movement and medium to strong light. Do not place them on the rock work as this can result in falls and/or cause tissue laceration, infection, and death. This coral can be semi-aggressive. It sends out long sweeper tentacles and so should be given a good 6 inches of clearance all around.

  • Minimum Tank Size / Length:50 gallons (190 L) or larger
  • Marine Lighting: Moderate to high
  • Temperature: 74° – 83° F (23° – 28° C)
  • Salinity / Specific Gravity: 1.023 – 1.026
  • Water Movement: Low to moderate
  • Water Region: Bottom of the aquarium

Compatibility and Social Behaviors

Heliofungia coral is peaceful with all the genus and species within the Faviidae family. However it has tentacles that are very long, so can be semi-aggressive with other corals. It can also move a little bit, so it is a good idea to not have any other corals on the substrate with it except its kin. Sadly the Plate Corals are more often stung by other corals, and they do not usually recover from these stings.

Be aware of the fish kept with these corals as the Plate Coral may be able to eat small and sick fish. Also, Butterfly fish may pick at the tentacles of the Plate Coral, due to the fact that they resemble anemones. Clownfish may at times reside with the Heliofungia, but if these fish are very large they can injure the coral.

In the wild, shrimp from the Periclimenes genus including P. kororensis, P. holthuisi, and P. tenuipes are found within the coral’s polyps. Others found with them are the commensal shrimp Metapontonia fungiacola and Hamopontonia corallicola, as well as a very small white pipefish called Siokunichthys nigrolineatus.

Sex – Sexual differences


Breeding and Reproduction

The large polyp stony (LPS) corals are male and female and can reproduce both sexually and asexually. In the wild they reproduce sexually by releasing eggs and sperm at the same time, resulting in a fertilized egg which then forms into a free-swimming planula larva.Eventually the planula larvae settles onto the substrate, becoming plankters. This then forms a tiny polyp which begins to excrete calcium carbonate and develops into a coral. Planula larvae are extremely vulnerable to predation, and very few survive.

The Heliofungia genus has been known to brood their young instead of open water spawning. This coral will also reproduce asexually by budding on the underside of the skeleton, but not on the top like other Fungid.

In captivity, propagation of H. actiniformis can be done by cutting the disc into multiple pie shaped wedges. Use a dremel saw or other saw that can quickly saw through the bone. Make sure the animal has been well fed and is healthy before attempting this type of fragmentation.

Potential Problems

A strength of the Heliofungia genus is that it is known to be very resistant to bleaching, but it has a couple of weaknesses. It does not usually recover from stings from other corals. Any tissue damage quickly brings on brown jelly infections and eventual death in most cases. A freshwater bath and siphoning off the infected area may help.


Heliofungia Corals for Sale: The Plate Coral H. actiniformis is very easy to find at pet shops and on line. Online they can run about $3o.00 USD or more depending on size and/or color.


 Anemone Coral (Heliofungia actiniformis) (Image Credit: Bernard DUPONT, Wikimedia Commons CC BY-SA 2.0 Generic)