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   The intense green found on the Green Stony Pillar Coral is much sought after, yet this is still an affordable coral!

   The Green Stony Pillar Coral Psammocora contigua typically seen in the aquarium trade is green. It has long been known as the Branched Sandpaper Coral and Pillar Coral. But once it took hold in the aquaculture world, describing it for its gorgeous color has become the norm. The popular common name it is known for is Green Stony Pillar Coral, along with Dark Green Contigua. The beautiful green of this specimen, which is often more of a dark and intense green, can easily become a centerpiece in your tank.

   The P. contigua grows in a combination of forms, including flattened branches, column formations, and irregular nodules. Corallites are very shallow and fine, so the surface of the coral looks very smooth. Like all members of their family, Siderastreidae, when their polyps are retracted the corallites on the surface make a very pretty, randomly place flower or star-like patterning. In the aquarium trade, they are often confused with Porites. They come in pale to dark grayish brown and green.

   The Green Stony Pillar Coral is easy to care for, yet is not as common in the aquarium trade as other small polyp stony (SPS) corals. This coral is very tolerant of aquarium parameters, including salinity variations, and wide varieties of light and water flow. They prefer moderately intense, full spectrum lighting and moderate to strong water flow. Carefully acclimate them to stronger lighting over a few months. P. contigua is relatively peaceful as far as SPS corals are concerned, so they will work out nicely in most tanks.

   Like all SPS corals, the Green Stony Pillar Coral gets much of its nutrition from the zooxanthellae that lives in it tissues. But it will also benefit from small food particles found in Marine Snow, and phytoplankton preparations that are now available. This is a hard coral that may not be susceptible to many diseases, but can still succumb to diseases typical to small polyp stony (SPS) corals. The Psammocora genus have been propagated in captivity, but they do not grow quickly.

Scientific name

   Family: Siderastreidae
   Species: Psammocora contigua

Distribution / Background

   Psammocora Coral Information: The Green Stony Pillar Coral Psammocora contigua was described by Esper in 1797. Some common names they are known for are Dark Green Contigua and Branched Sandpaper Coral, and Pillar Coral. Some general names for the Psammocora genus are Pillar Coral, Cat’s Paw Coral, Encrusting Sandpaper Coral, and Starry Petaloid Coral. It has been propagated in captivity.

   Where Psammocora Corals Are Found: The Psammocora contigua are found in waters from eastern Africa and the Red sea to Samoa, as well as in Australian waters including the Great Barrier Reef, Coral Sea and all of the southern waters except Solitary Islands and Shark Bay.

   Psammocora Coral Habitat: P. contigua is found in a wide range of habitats including reef fronts. They are found at depths ranging from 0 – 131 feet (0 – 40 m). Like other members of the Psammocora genus, they are found in varying reef zones. Though not common in the aquarium trade, these corals are very tolerant of salinity variations, water flow, and light.

Status

   The Psammocora contigua is on the IUCN Red List of Endangered Species as Near Threatened (NT).

Description

   What do Psammocora Corals look like: The P. contigua grows in a combination of forms, including flattened branches, column formations, and irregular nodules. Corallites are very shallow and fine, so the surface of the coral looks very smooth. They come in pale to dark grayish brown and green. In the aquarium trade, they are often confused with Porites. Aquacultured specimens can be obtained in beautiful greens, which are often more of a dark and intense green color.

Difficulty of Care

   Psammocora Coral Care: The Green Stony Pillar Coral P. contigua is easy to care for. They tolerate wide varieties of light and water flow, though favor moderately intense, full spectrum lighting and moderate to strong water flow. Just carefully acclimate them to stronger lighting over a few months.

Foods / Feeding

   Psammocora Coral Feeding: In the wild, Psammocora corals have developed several feeding strategies. Through a symbiotic relationship with a marine algae, known as zooxanthellae, they receive the majority of their nutrients. They also capture planktonic organisms and microscopic food particles from the water column and can absorb dissolved organic matter.

   In captivity, they do best in well-feed reef tanks. Like all SPS corals, it gets much of its nutrition from the zooxanthellae that lives in it tissues. But it will also benefit from small food particles found in Marine Snow, and phytoplankton preparations that are now available.

Aquarium Care

  Pristine tank conditions are typically needed to keep all SPS corals. Keep the nitrate levels low, and maintaining calcium and alkalinity levels. Typically you can do water changes of 20% a month, 10% biweekly or 5% weekly. It has been noted that 5% weekly water changes replenish many of the needed additives. With higher concentrations of coral with calcareous skeletons, there may be a need put in additional additives to maintain proper levels for good growth.

   Suggested levels for Psammocora species are:

  • Calcium:  400 to 450 ppm (closer to 450). If the coral does not have enough calcium, it will not grow.
  • Alkalinity:  3.2 TO 4.5 MEQ/L (8 to 10 dKh – 10 is recommended)
  • Phosphates:  0, zero. Phosphates are the worst of all and all corals hate them.
  • Magnesium:  12000-1350. 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 Green Stony Pillar Coral, along with some fish for organic matter production. A mature tank is recommended.

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

   Like other Psammocora, they tolerate wide varieties of light and water flow, even salinity variations. But they favor moderately intense, full spectrum lighting and moderate to strong water flow. Carefully acclimate them to stronger lighting over a few months. Make sure that no other corals can come in contact with your Psammocora. This Branched Sandpaper Coral is not very aggressive so needs to be positioned at least 6″ away from other corals.

  • Minimum Tank Size / Length: 20 gallons (75 L) or larger
  • Marine Lighting: Moderately intense; also high, but acclimate slowly
  • Temperature: 73° – 81° F (23° – 27° C)
  • Salinity / Specific Gravity: 1.023 – 1.025
  • Water Movement: Moderate to strong
  • Water Region: Middle of the aquarium, though this is dependent on your lighting strength

Compatibility and Social Behaviors

   Psammocora are not aggressive corals, nor do they posses strong defenses. Because of this, they must be placed away from any aggressive or defensive coral. It needs to be kept at least 6″ away from other corals so they cannot reach it with their tentacles. P. contigua may get along with their same species, but distance between them and other species may be wise. The fact that they are not aggressive may be an indication they will tolerate others from their own genus.

Sex – Sexual differences

   No sexual difference in appearance is known.

Breeding and Reproduction

   The small polyp stony (SPS) 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. Psammocora spp. reproduce asexually as well, by popping out new colonies from their surface, which eventually will break off to start new colonies. In the wild small polyp stony (SPS) corals also spread from breakage due to storms and fragmentation.

   When propagating Psammocora corals, using high speed water-cooled saws for the thicker areas is recommended. Then simply cut a branch and glue the frag to a plug or rock. You can use the 2-part epoxy or underwater putties. Gloves are suggested. Give the frag ample water flow. They do not grow quickly. Noteworthy, some propagators suggest a suspension of frags by using string/plastic wire. That way the coral does not touch any surrounding surfaces. This seems to support the notion of the “free living” aspects that some species in this genus seem to enjoy.

Potential Problems

   The Psammocora spp. are hard corals that may not be susceptible to many diseases. But they can still get the same illnesses that any other small polyp stony (SPS) coral can get under poor conditions. In general, if your stony coral has any kind of tissue recession, you can cut off the unhealthy part. Just make sure you cut into some of the healthy part also, to be sure there is no disease encroaching on the healthy tissue. Also, keep out the cyanobacteria and algae with good water movement, and your coral will stay happy.

Availability

   Psammocora Corals for Sale: The Green Stony Pillar Coral or Branched Sandpaper Coral P. contigua is sometimes difficult to find at pet shops and on line. Online they can run about $20.00 to $30.00 USD or more depending on size.

References