Keeping a marine aquarium is popular and understandably so, be it fish only or reef. The reef type is the more natural as it has a mix of corals and fish forming a mini reef. Keeping a mini coral reef is not that difficult nowadays (always subject to what life forms are kept) as the equipment available is much more advanced than, say, 20 years ago. What corals to consider is a major question, and one that could be introduced to a correctly aged and mature aquarium is the sun coral, properly called Tubastrea aurea. In the wild it could grow to around 20 ins (circa 50cm).
The natural colour of the sun coral is a vivid orange to yellow. It lives on Indo-Pacific reefs and is a very common species there. In the wild the coral lives at the mouth of small caves or in a crevice. This means there is one big advantage with this coral and that is that it does not rely on symbiotic algae. Nevertheless the aquarist needs to pay proper attention to the lighting system as no doubt there are other corals in the aquarium that do have symbiotic algae.
The sun coral feeds by trapping food particles with its tentacles, these tentacles are around each head. Think of a vase of round flowers with very short stalks, the coral is a little like that. With high quality seawater, proper placing and a reasonable but not over strong seawater flow the coral should be happy. Properly fed and placed the coral is likely to reach a size of around 4 ins (circa 10cm).
Introducing the sun coral to a mature aquarium is simple. The spot it is to be placed in has already been selected of course, an area lower down with reasonable seawater flow. The coral should not be removed from the bag, but let the bag hang in the aquarium seawater. Remove a small spoonful of seawater from the bag and discard, replacing with a spoonful of aquarium seawater. Repeat this slowly until the whole bag has been refilled with aquarium seawater, the number of spoonfuls can be reasonably guessed. On completion, the coral can be placed in the aquarium again ensuring there isn’t any exposure to the air.
It is likely the newly introduced sun coral will remain closed for a week or more. If it appears to be closed for an excessive amount of time (disregarding any impatience of the aquarist!) feed the fish with some de-frozen food, brine shrimp or the like. This could tempt the coral to open. Another way is to squeeze a shrimp in the seawater.
The coral could well feed when the fish are fed as above, though not every time. However, if not, then it can and should be fed using a ‘small-grip’ pair of tweezers. Consider each ‘flowerhead’ as an individual and place a small piece of food, such as a bit of shrimp, in each flowerhead. Fairly large bits of food can be used. Feeding the coral is essential and should be done each day or every other day, this presumably is because of the lack of symbiotic algae. A well fed coral could well produce new heads, which appear at the base of the existing ones.
The sun coral is something a little different for the captive reef. As said there aren’t any symbiotic algae and therefore it can live in an area of no use to other corals. The coral is not fully an ‘easy option’ as it needs feeding attention regularly. The colour is lovely and once settled it will add colour and a difference to a lesser used area of the aquarium.