Duncanopsammia axifuga

• Indo-Pacific
• Moderate Care Level
• For Intermediate to Advanced Hobbyists
• Moderate to Low Placement in Reef Tank

Duncanopsammia axifuga, commonly known as the Duncan Coral or Duncanopsammia, is a species of LPS (Large Polyp Stony) coral native to the Indo-Pacific region, found in countries like the Philippines, Indonesia, and Australia. It is renowned for its large, fleshy polyps that form a branching structure, often extending several inches from the central base. The polyps are typically bright green, yellow, or brown with contrasting bright tips (often yellow or orange). In high light conditions, these tips can appear even more vibrant, enhancing the coral's striking appearance. The species is slow-growing, and it tends to form a bushy, encrusting colony over time. The coral’s long, waving polyps give it a soft, lush look that contrasts beautifully against other types of corals in a reef tank.

Placement in the Tank

Duncanopsammia axifuga prefers to be placed in moderate to low light zones of the reef tank, ideally in the middle or lower regions, where it can receive indirect light or filtered light through the water column. This coral is light-sensitive, and while it can tolerate lower light conditions, too much light can result in bleaching or tissue retraction. The optimal light intensity for Duncanopsammia axifuga is between 100-200 PAR. When placed in intense lighting, it may retract its polyps and lose its vibrant colors, so gradual acclimatization to stronger light sources is key.

In terms of water flow, Duncanopsammia axifuga does well in gentle to moderate water movement. While it requires flow to help with feeding and waste removal, excessive water current can cause the polyps to retract or even result in damage to the tissue. A gentle, undulating current is ideal for the coral, as it allows its polyps to fully extend and catch small food particles. High turbulence can be detrimental, leading to polyp retraction and weakened growth.

Water Parameters

Maintaining stable and optimal water conditions is critical for the long-term health of Duncanopsammia axifuga. The recommended water parameters for this coral species are as follows:

• Temperature: 24°C to 28°C (75°F to 82°F). 26°C (79°F) is optimal. Temperature fluctuations should be minimized, as this coral is sensitive to temperature stress.
• Salinity: 1.023–1.025 specific gravity (SG), with 1.024 being ideal. Stable salinity is vital, as this coral can become stressed by large swings in salinity.
• pH: 8.0 to 8.4, with 8.2 being the ideal pH for the growth and health of Duncanopsammia axifuga. Consistent pH levels are important to prevent fluctuations that may affect the coral's ability to absorb calcium.
• Alkalinity (dKH): 8-12 dKH, with 9-10 dKH being ideal for skeletal growth. Maintaining proper alkalinity is crucial to avoid swings in pH and calcium levels.
• Calcium: 400-450 ppm. Maintaining an appropriate calcium level supports the development of the coral's calcium carbonate skeleton.
• Magnesium: 1250-1350 ppm. Magnesium helps stabilize calcium and alkalinity levels in the tank.
• Nitrate: Below 5 ppm. Elevated nitrate levels can encourage algae growth and reduce the health of Duncanopsammia axifuga.
• Phosphate: Below 0.03 ppm. High phosphate levels can lead to poor coral growth and nutrient imbalances, making it essential to keep phosphate low to prevent competition from algae.

Feeding

While Duncanopsammia axifuga is photosynthetic, relying on the symbiotic algae zooxanthellae for most of its energy, it can benefit from supplemental feeding. This species is an efficient filter feeder, capable of capturing a wide range of particulate food that enters the water column. It will take advantage of small planktonic organisms such as mysis shrimp, brine shrimp, zooplankton, and phytoplankton. You can also feed it liquid coral foods designed to feed LPS corals.

Feeding should be done 2-3 times a week, depending on the tank's overall food availability. Duncanopsammia axifuga benefits from target feeding as it allows for more direct nourishment to its polyps. However, it's essential not to overfeed, as excess nutrients can degrade water quality and encourage undesirable algae growth.

Maintenance and Care

Proper maintenance is crucial to ensuring Duncanopsammia axifuga thrives in a reef tank. Key care factors include:

• Water Changes: Regular weekly water changes of 10-15% are important for maintaining water quality, replenishing essential elements, and removing any toxins that may build up.
• Monitoring Water Parameters: Constantly check parameters such as pH, calcium, alkalinity, nitrate, and phosphate to ensure they stay within the recommended ranges. Small fluctuations can stress Duncanopsammia axifuga and lead to reduced polyp extension or coral tissue loss.
• Space for Growth: Although slow-growing, Duncanopsammia axifuga can eventually spread across larger areas of rock. It is important to place the coral in an area with adequate space so it doesn’t come into contact with aggressive corals or crowd other species. The coral will benefit from a little room to expand as its branching structure develops.
• Pest Control: Like many LPS corals, Duncanopsammia axifuga can be susceptible to pests such as Aiptasia, flatworms, and nudibranchs. These pests can cause tissue damage and hinder the coral’s health. Regular inspection of the coral for pests is important, and quick action should be taken if pests are identified.

Compatibility

Duncanopsammia axifuga is generally considered peaceful and will coexist well with other non-aggressive corals, especially those that do not compete for light or space. It can be placed alongside other LPS or soft corals with similar water flow and light requirements. However, it can be territorial and will need sufficient space from aggressive corals, such as SPS species or large LPS with sweeping tentacles (e.g., Favia or Echinophyllia), as they may sting or overgrow the Duncanopsammia.

Conclusion

Duncanopsammia axifuga is a beautiful, slow-growing LPS coral that provides a soft, bushy look to the reef tank, making it an excellent choice for intermediate to advanced hobbyists. Its large polyps and vibrant colors create an appealing contrast against other corals, and with proper care, it will thrive in a well-maintained reef aquarium. By maintaining stable water conditions, adequate lighting, moderate flow, and occasional feeding, Duncanopsammia axifuga will continue to grow and thrive, adding both visual appeal and interest to the tank.