Euphyllia cristata (Joker)

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

Euphyllia cristata, commonly known as the Joker Coral or Hammer Coral (sometimes referred to as Torch Coral due to its resemblance to similar species), is a stunning species of LPS (Large Polyp Stony) coral native to the Indo-Pacific region, including areas such as the Philippines, Indonesia, and the Great Barrier Reef. This coral species is admired for its unique, colorful polyps and elegant, branching structure that can form a dense, coral colony over time. The most striking feature of the Joker variant is its vibrantly colored tips, which can range from bright greens, pinks, and yellows, contrasting against its typically green or purple base. This gives the coral a vibrant and almost "comic-like" appearance, with vivid contrasting hues that give it the "Joker" name. The polyps themselves can be long and sweeping, giving the coral a flowing and dynamic look within a reef aquarium.

Placement in the Tank

Euphyllia cristata (Joker) thrives under moderate to high lighting conditions. A light intensity of 150-250 PAR is ideal for this species, allowing its vibrant colors to fully develop. While it is adaptable to lower light conditions, too little light can result in reduced coloration and poor polyp extension. It is recommended to place the Joker Coral in the middle or upper regions of the reef tank where it can receive adequate lighting, but be mindful of not exposing it to direct, intense lighting for extended periods, which can stress the coral.

In terms of water flow, the Joker Coral prefers moderate to gentle water movement. A gentle, undulating current is ideal to allow its long polyps to sway gracefully without damaging the tissue. Strong currents can cause the polyps to retract or cause physical damage over time. Similarly, low flow can limit the coral’s ability to capture food effectively.

Water Parameters

To ensure the Joker Coral thrives, maintaining optimal water conditions is essential. The recommended water parameters are as follows:

• Temperature: 24°C to 28°C (75°F to 82°F), with 26°C (79°F) being ideal for maintaining a stable environment.
• Salinity: 1.023–1.025 specific gravity (SG), with 1.024 being optimal. Consistency in salinity is important for the overall well-being of the coral.
• pH: 8.0 to 8.4, with 8.2 being the optimal pH. Maintaining stable pH levels prevents stress and enhances the coral’s ability to absorb nutrients.
• Alkalinity (dKH): 8-12 dKH, with 9-10 dKH being ideal for robust skeletal formation.
• Calcium: 400-450 ppm, which supports healthy skeletal growth.
• Magnesium: 1250-1350 ppm, necessary for stabilizing calcium and alkalinity levels in the water.
• Nitrate: Less than 5 ppm to avoid nutrient imbalances and algae growth that could harm the coral.
• Phosphate: Below 0.03 ppm, as elevated phosphate levels can inhibit the coral’s ability to thrive and lead to algae competition.

Feeding

Euphyllia cristata (Joker) is a photosynthetic coral, utilizing zooxanthellae algae to produce the majority of its nutritional requirements. However, it is also an effective filter feeder and will benefit from supplemental feeding in the aquarium.

The coral will capture small planktonic food, such as mysis shrimp, brine shrimp, zooplankton, and phytoplankton. It is best to feed the Joker Coral 1-2 times a week, either through targeted feeding with a turkey baster or by adding liquid coral foods designed for LPS corals. Be sure to avoid overfeeding, as excess nutrients can lead to water quality issues and excessive algae growth.

Maintenance and Care

To ensure the long-term health and growth of Euphyllia cristata (Joker), regular maintenance is necessary:

• Water Changes: Perform 10-15% weekly water changes to maintain water quality and remove toxins. Regular water changes help replenish essential minerals that corals need to thrive.
• Water Parameter Monitoring: Regularly check the parameters such as pH, calcium, nitrate, phosphate, and alkalinity to ensure they remain within the recommended ranges.
• Space for Growth: Over time, Euphyllia cristata will grow and may need adequate space to avoid crowding other corals. As it forms large branches, it’s important to space it apart from aggressive corals like SPS and other LPS species with long-reaching tentacles.
• Pest Control: Check for Aiptasia, flatworms, nudibranchs, or other pests that may damage the coral. Prompt action is necessary to remove pests from the tank and ensure the coral’s health.

Compatibility

Euphyllia cristata (Joker) is a peaceful coral, making it suitable for tanks with other non-aggressive corals. It can be housed with other LPS species, such as Favia, Blastomussa, or Acanthastrea, and soft corals like Zoanthids and Mushrooms. However, Euphyllia cristata can be territorial and should be placed away from aggressive species that might sting or damage it. SPS corals or other long-tentacled LPS, such as Torch Coral or Bubble Coral, may be incompatible if placed too close due to their long sweeping tentacles.

Conclusion

Euphyllia cristata (Joker) is an excellent addition to any reef tank, thanks to its vibrant, colorful polyps and graceful, flowing appearance. It is a moderate care LPS coral, making it suitable for intermediate to advanced hobbyists. With the proper lighting, water flow, and feeding regimen, the Joker Coral can thrive and grow into a stunning centerpiece for your reef tank. Its bold coloration and dynamic tentacle movement will add a captivating visual element to your aquarium, creating a lively and attractive environment. With proper care and space, Euphyllia cristata (Joker) will bring both beauty and movement to your coral collection for years to come.