The Blue Coral Heliopora coerulea is actually a soft coral, rather than a stony coral. But it is quite a unique soft coral with a very interesting history. It is the only remaining species of its family, Helioporidae. At one time its family was a dominant coral in the world’s oceans. Its demise and the extinction of all its relatives came not from global warming, but from massive cooling of the seas during the last ice age. Today this coral only survives in a narrow band of tropical waters along the equator.
Another unique aspect of the Blue Coral is that it is one of only two types of familiar Octocorals that calcify an external skeleton. The other is the Organ Pipe Coral Tubipora musica. These two are also the only Octocorals with colorful skeletons, blue and red respectively.
Heliopora colonies can be arborescent, plate-like, or form columns. Its skeleton, which is made of aragonite, is covered in a tan to brown or greenish-gray colored tissue. It has small feathery polyps all over that can be grayish white to olive green. Its interior becomes blue due the coral’s ability to extract iron from surrounding water into a blue salt that is deposited onto the skeleton.
H. coerulea is often overlooked in nature, because its beautiful skeleton is usually hidden unless a portion is broken off. In the water it looks very much like the fire corals, hard corals in the Millepora genus such as the Fire Coral Millepora alcicornis. Thus its common names include not only Blue Coral, Blue Ridge Coral, and Blue Lettuce Coral, but also Blue Fire Coral.
The Blue Coral is easy to care for, making it a good beginner’s coral. It likes a strong current, but can do fine with a moderate water flow that is turbulent but not one directional. One directional water flow is not suggested as it will stress the coral and harm the polyps. It also likes strong lighting and will thrive under metal halides, It can grow under moderate lighting as well, but will need to have its diet supplemented with fine particulate foods. Tall tanks are great for these corals due to their upward growth.
To learn more about some of the most fascinating soft corals see:
What Are Octocorals?
This video shows the various ways a Blue Coral can appear. Their polyps come out at feeding time and their “blue” coloring is actually inside the coral with more of a tannish skin. When they shed, they pull in their polyps and they slough off a layer of slime, similar to Toadstool Leather Corals. They like strong turbulent flow (not linear which can damage the polyps) and strong lighting. Moderate lighting can work, however they will have to be fed to make up for the lack of light. This beginner coral is a little odd ball that will be a joy to own!
Scientific name
Order: Helioporacea – Blue Coral
Family: Helioporidae
Species: Heliopora coerulea
Distribution / Background
Soft Coral Information: The Blue Coral Heliopora coerulea was described by Pallas in 1766. It is the only known living species in its family, Helioporidae, and the only species in its genus. These corals, although in the soft coral category, contribute to reef building.
The absolute beauty of the coral’s blue skeleton has made it popular with curio collectors. Similar to the Pipe Organ Coral, this coral is gathered for its blue aragonite base by collectors and those who make and sell jewelry. Some common names these corals are know for are Blue Coral, Blue Ridge Coral, Ridge Coral, Blue Lettuce Coral, Lettuce Coral, and Blue Fire Coral. H. coerulea has been propagated in captivity.
Where Heliopora Corals Are Found: The Heliopora genus are found around Australia; the north and central great barrier reef, the Coral Sea to the east, and south to North West Cape on the west coast.
Heliopora Coral Habitat: The Heliopora genus are found on northern tropical reef flats and upper reef slopes, where they tend to be the dominant coral. The depths they inhabit can be from 0 – 30 feet, (0 – 9 m) where the water has good movement and plenty of light.
Status
The Blue Coral Heliopora coerulea is on the IUCN Red List for Endangered Species as Vulnerable (VU).
Description
What do Heliopora Corals look like: The name origin of the Blue Coral Heliopora coerulea comes from the color of the animal’s aragonite skeleton. Its interior becomes blue due the coral’s ability to extract iron from surrounding water into a blue salt that is deposited onto the skeleton. Heliopora colonies grow in arborescent, plate-like or column formation. They have compacted circular tubes within the base which hold the retractable polyps.
A healthy coral is covered in a tan to brown or greenish-gray colored tissue with small feathery polyps all over that can be grayish white to olive green. They have the ability, like some leather corals to shed a layer of skin to keep algae and bacteria build up away. As the coral grows, the new growth is a lighter color than the rest of the tissue. These corals can grow to over 6 feet (2 m) tall.
Blue Ridge Coral Photo Courtesy John RiceDifficulty of Care
Soft Coral Care: The Blue Coral H. coerulea is easy to care for, making it a good beginner’s coral. It likes a strong current, but can do fine with a moderate water flow that is turbulent but not one directional. One directional water flow is not suggested as it will stress the coral and harm the polyps.
It likes strong lighting and will thrive under metal halides, It can also grow under moderate lighting, but will need to have its diet supplemented with fine particulate foods. Tall tanks are great for these corals due to their upward growth.
Foods / Feeding
Soft Coral Feeding: In the wild, Heliopora corals have developed several feeding strategies. They can capture planktonic organisms and microscopic food particles from the water column, absorb dissolved organic matter, and have a symbiotic relationship with a marine algae known as zooxanthellae, where they also receive some of their nutrients.
In captivity, the Blue Coral will generally use bright light and zooxanthellae as their main food source, although Marine Snow, Artemia nauplii, rotifers and other fine particulate foods can be supplemented.
Aquarium Care
Stable tank conditions are needed to keep the Heliopora genus. Doing water changes of 20% a month or 10% biweekly is needed, although it is suggested that doing 5% water changes once a week will replenish many of the needed additives. Calcium and other trace elements can be added to maintain proper levels for good growth. Iron supplementing would also be a good idea for this coral.
Suggested levels for Heliopora species are:
- Calcium: 400 – 450 ppm
- Alkalinity: 3.2 – 4.8 MEQ/L (8 to 11 dKh – 10 is recommended)
- Phosphates: 0, zero.
- Magnesium: 1200 – 1350 ppm. (Magnesium makes calcium available, so if your calcium is low, check your magnesium levels before adding any more calcium.)
- Strontium: 8 – 10
Aquarium Parameters
| Quick Reference Chart | |||
|---|---|---|---|
| Lighting: |  |  |  |
| Water Flow: |  |  |  |
| Temperament: |  |  |  |
An established live rock/reef environment is what is needed for your Blue Coral, along with some fish for organic matter production. Tall tanks are great for these corals due to their upward growth.
Provide proper lighting and water movement. They like strong lighting and can do well under Metal Halides but can also grow under moderate lighting. They also like a strong current, but can do fine with a moderate water flown that is turbulent but not one directional. One directional water flow is not suggested as it will stress the coral and harm the polyps. This is a peaceful species and can be kept with other species that are also peaceful.
- Minimum Tank Size / Length:50 gallon (190 L) or larger
- Marine Lighting: Moderate to high
- Temperature: 76° – 84° F (25° – 29° C)
- Salinity / Specific Gravity: 1.023 – 1.025
- Water Movement: Moderate and turbid, one directional flow should be avoided
- Water Region: Bottom of the aquarium
Compatibility and Social Behaviors
The Blue Coral is peaceful and is usually fine within proximity to other corals that are peaceful. H. coerulea have very small feathery tentacles, and do not form sweeper tentacles at night. Generally it is the “victim” of other corals due to its passive nature. Any corals that emit strong toxins will kill your Blue Fire Coral.
Sex – Sexual differences
No sexual difference in appearance is known.
Breeding and Reproduction
The Heliopora genus will continue to grow at the tips forming new growth, indicated by a lighter color than the rest of the tissue. The best way to frag this coral is to break it away, and either rubber band, cement or epoxy the piece to a plug or rock.
Potential Problems
The Heliopora genus is a very hardy coral and has few problems as long as its needs are provided for.
Availability
Soft Corals for Sale: The Blue Coral H. coerulea is easy to find at pet shops and on line. Online they can run about $50.00 USD or more, depending on size and/or color.
References
- Animal-World References: Marine and Reef
- Eric Borneman, Aquarium Corals : Selection, Husbandry, and Natural History , TFH Publications, 2001
- Anthony Calfo, Book of Coral Propagation, Volume 1 Edition 2: Reef Gardening for Aquarists, Reading Trees; 2nd edition, 2007
- Harry Erhardt and Horst Moosleitner, Marine Atlas Volume 2, Invertebrates (Baensch Marine Atlas), Mergus Verlag GmbH, Revised edition, 2005
- J.E.N. Veron, Corals of Australia and the Indo-Pacific , University of Hawaii Press; 2 Rev Ed edition, 1993
- Bob Goemans, Blue Coral, Animal Library, Saltwatercorner.com
Featured Image Credit: Heliopora coerulea Maldives by Frédéric Ducarme, Wikimedia Commons CC SA 4.0 International
