SPS Coral Database          ReefKeeping 101

SPS (Small Polyp Stony) corals are the major reef builders in the wild.  They form the prominent reef structures that most people associate with reefs.  SPS coral polyps are relatively small and inconspicuous compared to the coral skeleton, unlike LPS corals whose polyps are the major identifying feature of those corals.  SPS corals grow in many different forms and it is the skeletal growth pattern and shapes of the corallites (skeletal housing for individual polyps) that is primarily used to identify these corals.  Even so, accurate identification of this group of corals is much more difficult than with the other tank inhabitants and many SPS coral ID's are tentative at best.  This group also has very few common names in usage.

The principal family of SPS corals is called Acroporidae.  This family includes the Acropora and Montipora genus which constitute the majority of SPS corals kept in the hobby.

The SPS growth patterns can be categorized into several basic forms.

	Staghorn Upwards branching, usually with large cylindrical branches that branch only infrequently.  Shape resembles the horns of a deer, hence the name.
	Corymbose Forms flattened table type formations with short upwards pointing branches.
	Table / Plate Forms flat plates that may be positioned horizontally in tiers or upwards in a cup like arrangement called a whorl.
	Bushy Forms random looking heavily branched structures.  The branches may interlock together.
	Encrusting The coral encrusts the substrate that it leaves on and does not have a typical growth pattern of its own.
	Digitate Forms short, non-dividing branches like the fingers on a hand.
	Arborescent Forms tree-like branches

As a group, SPS corals are the most difficult to keep in the home reef tank.  Until relatively recently, they were impossible to keep.  Now that their needs for high intensity lighting, vigorous water motion and high demands for calcium, magnesium and strontium are understood better, they are becoming easier to keep.  Still they are the most demanding on the hobbyist and generally are the highest cost to maintain.

Most hobbyists do not start out with SPS corals and this is probably a good thing.  Most hobbyist report difficulty in maintaining SPS corals until the tank has matured for a considerable period of time (6 months to a year), even though all measurable tank parameters are within requirements.  Growth of coralline algae within the tank is a good sign that the tank conditions will support SPS corals.  I have seen recommendations that SPS corals should not be added until the coralline algae spots on the tank walls grow to the size of a dime and that is probably a good rule of thumb to follow.

Guidelines to buying SPS corals:

• Avoid specimens that have obvious areas of tissue recession or die-off.  Although it is tempting to try to save the coral, once SPS corals start into decline it is difficult to reverse the process.  A last ditch effort to save a dieing colony is to fragment it into the remaining small healthy sections and mounting them onto coral rubble using superglue.  More often than not, this plan fails to give the desired results, but is usually worth a try.
• Avoid specimens that are extremely pale or white looking.  This may be a sign of bleaching which may lead to the corals death regardless of the conditions you provide.  Some SPS corals are naturally fairly white so this can be difficult to determine at times.
• Chose propagated frags over large wild colonies when possible.  There are several good reasons for this.  One is that it is more reef friendly since the specimen was not removed from the reef.  Second, it has been acclimated to normal aquarium conditions and is more likely to adapt and grow within your own tank.  Third is that it is cheaper, although you must be patient to allow it time and space to grow.  Lastly, it is very satisfying to grow a complete coral head from a small fragment of coral.

See acclimation procedure for further information on introducing SPS corals to the tank.