Stylophora are popular small polyp stony (SPS) corals in the reef aquarium hobby. Their relative hardiness makes them a good starting point for aquarists interested in SPS corals. Commonly known as “Cat’s Paw Coral,” their nickname comes from their distinct branching shape. Stylophora species are naturally found across the Indo-Pacific region and the Red Sea.
Appearance and Common Varieties
Stylophora corals form branching colonies with thick, finger-like branches and blunt, rounded ends. When their polyps are fully extended, the coral takes on a fuzzy appearance. This morphology helps differentiate Stylophora from similar corals like Seriatopora (Bird’s Nest), which have sharper, more pointed branches. They exhibit a wide spectrum of colors, including pink, purple, green, orange, magenta, and brown. The “Milka” Stylophora is a well-known purple variant. Other sought-after color morphs include classic pinks and vibrant electric greens, contributing diverse aesthetics to a reef tank.
Essential Care Parameters
Lighting
Stylophora corals thrive under moderate to high-intensity lighting. A PAR (Photosynthetically Active Radiation) level of 200-350 is recommended for optimal growth and color retention, though some aquarists aim for 300-400 PAR. These corals host photosynthetic algae called zooxanthellae within their tissues, which provide a significant portion of their nutritional needs through light.
Water Flow
Consistent and strong, yet indirect, water movement is beneficial for Stylophora. Proper flow helps prevent detritus from settling on the coral tissue, which can lead to tissue recession. It also ensures that the polyps receive adequate nutrients and remain clean. While Stylophora tolerates moderate flow, a robust and alternating pattern can promote better overall health and growth.
Water Chemistry
Stable water chemistry is important for the health of Stylophora and other stony corals. Calcium levels should be 420-440 ppm, alkalinity 8-9.5 dKH, and magnesium 1260-1350 ppm. Temperature should consistently remain between 75-80°F (23-28°C), and salinity should be kept at a specific gravity of 1.024-1.026, with 1.025 being a commonly targeted value. Nitrates should be maintained below 10 ppm and phosphates below 0.10 ppm. Although Stylophora are primarily photosynthetic, they benefit from occasional target feeding with plankton-like foods (e.g., rotifers, cyclops, or oyster eggs) to enhance growth and coloration.
Tank Placement and Growth Habits
Considering their light and flow requirements, Stylophora are best positioned in the mid-to-upper sections of a reef aquarium. Placing them on exposed rockwork ensures they receive ample, yet diffused, water movement. Stylophora are relatively fast-growing SPS corals. A small frag can develop into a substantial colony under stable and favorable conditions. Growth may initially be slow, but it can accelerate significantly once the coral becomes established in its environment.
These corals are peaceful and do not possess long, aggressive sweeper tentacles, making them suitable for mixed reef aquariums. However, provide some clearance from neighboring corals, as their short sweeper tentacles can extend approximately 1 inch (2.5 cm).
Addressing Common Problems
A common issue for Stylophora is “browning out,” which indicates insufficient light. If the coral’s vibrant coloration diminishes and it appears dull brown, a gradual increase in light intensity can restore its original hues. Conversely, “bleaching,” where the coral turns white, signals significant stress, often due to excessive light, elevated temperatures, or declining water quality. Addressing these environmental stressors, such as reducing light or stabilizing temperature, is important for recovery.
Stylophora can also experience tissue loss conditions like Slow Tissue Necrosis (STN) or Rapid Tissue Necrosis (RTN), where tissue recedes from the skeleton, sometimes from the base. These issues are linked to unstable water parameters, particularly fluctuations in alkalinity, or inadequate light reaching the coral’s base. Consistent monitoring of calcium, alkalinity, and magnesium is important to prevent such problems. Withdrawn polyps and pale appearance may indicate low potassium levels. Routine coral dips for new additions are a useful preventative measure against common coral pests.