Picture of SPS Corals, featuring an Antler Coral Acropora microphthalma
Small Polyp Stony (SPS) Corals – Featuring Antler Coral

   The Small Polyp Stony (SPS) corals have small polyps on a calcerous skeleton!

   The SPS corals have much smaller polyps than the LPS corals. LPS polyps are large and soft. SPS corals are usually either branching or plated. For the most part they enjoy bright light and strong currents. They are often fragile and are propagated by breaking off pieces.

   SPS corals used to be considered very challenging. A few discoveries in the last couple decades or so have brought them into the realm of the average aquarist. Nowadays it is not uncommon to see aquariums with various species of acropora, hydnophora, and other species of SPS corals growing and thriving.

   Since SPS corals usually occupy the reef flats in turbulent water, they require high light levels produced by VHO fluorescent or metal halide (see Mini-reef: Lighting) and strong water currents or turbulence. They also require very stable temperatures and excellent water quality (low organic nutrient levels) to thrive. Levels of calcium, strontium, and trace elements must be maintained. Sources vary on whether they need feeding or not. Probably some can be fed but it is not required to do so.

For information about setting up a reef tank see:Reef Tanks – Mini-Reef Aquarium Basics

Family: Acroporidae – Acropora Corals
Click for more info on Antler Coral
Acropora microphthalma
Click for more info on Cluster Coral
Acropora millepora
Click for more info on Finger Staghorn Coral
Acropora humilis
Click for more info on Green Fiji Acropora
Acropora bushyensis
Click for more info on Purple Tipped Acropora
Acropora tenuis
Click for more info on Staghorn Acropora
Acropora formosa
Click for more info on Staghorn Coral
Acropora cervicornis

Family: Acroporidae – Montipora Corals
Click for more info on Cabbage Coral
Montipora foliosa
Click for more info on Idaho Grape Montipora
Montipora undata
Click for more info on Montipora Plate Coral
Montipora capricornis
Click for more info on Plating Montipora Coral
Montipora peltiformis
Click for more info on Velvet Finger Montipora
Montipora digitata
Click for more info on Velvet Stone Coral
Montipora spongodes

Family: Agariciidae
Click for more info on Elephant Skin Coral
Pachyseris rugosa
Click for more info on Leaf Coral
Pavona decussata
Click for more info on Maldive Coral
Pavona maldivensis

Family: Merulinidae
Click for more info on Horn Coral
Hydnophora rigida
Click for more info on Ruffled Coral
Merulina ampliata

Family: Pectiniidae
Click for more info on Chalice Coral
Echinophyllia aspera

Family: Pocilliporidae
Click for more info on Bird's Nest Coral
Seriatopora hystrix
Click for more info on Cauliflower Coral
Pocillopora damicornis
Click for more info on Club Finger Coral
Stylophora pistillata

Family: Poritidae
Click for more info on Boulder Coral
Porites Porites sp.
Click for more info on Jeweled Finger Coral
Porites cylindrica

Family: Siderastreidae
Click for more info on Green Stony Pillar Coral
Psammacora contigua

What Are SPS and LPS Corals

   The coral reef is a beautiful world; comprised of anemones, mushroom corals, corals, crustaceans, and a myriad of other incredible animals. The word coral itself brings to mind the reef building hard corals, or stony corals. Stony corals produce a skeleton of calcium carbonate, which then becomes the foundation and building blocks of the coral reefs.

SPS Coral Picture of a Horn Coral Acropora humilisAcropora humilis Photo courtesy: Keith Berkelhamer

   The Small Polyp Stony (SPS) Corals can have complex elegant shapes, and dazzling colors.

   Convenient terminology in the aquarium industry is used to describe stony corals as either SPS corals (small polyp stony corals) or LPS corals (large polyp stony corals).   What they look like becomes immediately obvious when you compare the size of their polyps. SPS have much smaller polyps than the LPS.

  Though this generally works pretty well for the aquarist in recognizing a particular type of coral, it isn’t an exact description. There are occasional coral species whose polyps don’t fit the norm of their group, being too large or too small. From a scientific perspective, there is little objectivity and no real correlation between polyp size and classification.

Types of Coral

       The following genera are those corals usually referred to as Small Polyp Stony (SPS) Corals:

  • Acropora
  • Agariciid Corals
  • Anacropora
  • Astrocoeniid Corals
  • Disticophora
  • Echinophyllia
  • Heliopora
  • Hydnophora
  • Merulina
  • Montipora
  • Mycedium
  • Oxypora
  • Pachyseris
  • Pavona
  • Pectiniid Corals
  • Pocilloporid Corals
  • Siderastreid Corals
  • Stylophora
  • Pocillopora
  • Porites
  • Psammacora
  • Seriatopora
  • Stylophora

Live Coral Care

   Keeping a bit of coral reef in the home aquarium is an exciting and rewarding adventure. Reef tanks were once considered very difficult to keep. Keeping live coral is still somewhat demanding, but today the knowledge and equipment are readily available to the average hobbyist. Anyone with the desire to learn specific husbandry techniques and the willingness to purchase the proper equipment can keep a gorgeous reef aquarium. Of course the aquarist must invest his or her time in the care of these unique animals as well.

   Beautiful home reefs can be either a simple reef with hardier, less demanding animals, or a more complex reef with higher maintenance specimens. Stony corals are more demanding and take a more dedicated effort. So keeping stony corals is itself a step beyond a simple or beginner reef.

   Having reef-keeping experience is invaluable to successfully keeping hard corals. With some of the less demanding inhabitants you can hone your skills. You will develop an understanding of the unique habitat these animals thrive in.  Some of the best inhabitants for a beginning reef are soft and leather corals, coral anemones, and anemones. Once you’ve gained success in keeping these, you will be ready to keep the more delicate and demanding stony corals.

Corals For Sale

   Experience over the last few decades has strongly indicated that captive bred stony corals are much more adaptable and hardy than wild caught specimens. So it is better to acquire captive bred small polyp stony (SPS) corals or coral frags when possible. You’ll not only get a more durable coral, but there are often many beautiful color morphs available.

Featured Image Credit: John A. Anderson, Shutterstock