Bubble Coral care guide
Bubble Coral (Plerogyra sinuosa) — reef coral, 24-26 °C, PAR 50-125, salinity 1.024-1.026.
Compiled by Aquairi from published sources · Published · Updated
Overview
The Bubble Coral (Plerogyra sinuosa) is an LPS in the family Euphylliidae. During the day inflated grape-like vesicles cover the skeleton; at night the vesicles deflate and long sweeper tentacles extend to feed and to defend the colony.
Taxonomy
- Family: Euphylliidae
- Genus: Plerogyra
- Scientific name: Plerogyra sinuosa
- Common synonyms: Pearl Coral, Grape Bubble
Habitat
Widespread across the tropical Indo-Pacific. Wild colonies occur on protected reef slopes and shaded ledges at moderate depth, where light is filtered and water movement is gentle.
Tank requirements
- Temperature: 24-26 °C (75-79 °F)
- Salinity (SG): 1.024-1.026
- pH: 8.1-8.4
- Alkalinity (dKH): 8-11
- Calcium: 400-450 ppm
- Magnesium: 1280-1350 ppm
- Phosphate (max): 0.03 ppm
- Nitrate (max): 5 ppm
Placement and lighting
- Lighting (PAR): 50-125 PAR
- Flow: low
- Recommended tank age: 3 months
- Growth rate: 0.1-0.3 cm/mo
Mount on rockwork in the lower to middle aquarium with low flow and moderate light. Strong flow prevents bubble inflation; sharp objects can puncture the vesicles, so place on smooth substrate.
Feeding
Photosynthetic with strong response to spot-feeding after lights-out, when the sweeper tentacles extend. Feed mysis, brine shrimp or reef-roids one to two times per week.
Compatibility
Aggressive — sweeper tentacles can damage neighbouring corals at night. Allow a generous buffer around the colony. Reef-safe with shrimp and fish.
Care notes
Avoid handling the vesicles, which puncture easily. Keep alkalinity stable; sudden swings cause vesicle deflation that may persist for days.
Bubble Coral (Plerogyra sinuosa) Propagation Guide
Overview
Plerogyra sinuosa, the bubble coral, is a large-polyp stony coral in the family Plerogyridae. Its skeleton forms an inverted cone with thick corallites that grow outward like a maze in meandering ridges. In life the polyps display smooth, grape-like vesicles up to about 2.5 cm across that enlarge during the day to gather light and retract at night to expose the polyps and tentacles.
Reproductive Mode
In aquaria the bubble coral is propagated asexually by cutting the skeleton between heads. The coral also has an unusual natural budding method in which spines on the costae of young colonies elongate and develop into new polyps, a process uncommon among corals. For hobby purposes, dividing the meandering skeleton between separate heads is the practical route.
Fragging / Asexual Propagation
- Let the vesicles deflate, working at a time when the bubbles are retracted so the soft tissue is pulled in.
- Identify the meandering ridges of skeleton between separate heads or valleys.
- Cut carefully through the bare skeleton between heads with a band saw, not through the inflated bubble tissue.
- Keep the coral submerged and handle gently, as the bubble tissue tears easily.
- Mount each piece in low flow and moderate light and allow the tissue to heal over the cut edge.
Cutting only the skeleton between heads, with the bubbles deflated, limits damage to the delicate vesicle tissue.
Conditions for Propagation
Bubble corals inhabit shallow Indo-Pacific reefs and do best under moderate lighting and low flow, which lets the vesicles inflate without being battered. Stable temperature around 24-26 degrees Celsius, pH 8.1-8.4, and consistent alkalinity, calcium, and magnesium support healing of the cut frags.
Common Challenges
Bubble corals send out long sweeper tentacles, especially at night, that can sting neighboring corals, so frags need open space. The bubble tissue is also delicate and inflates with water, so rough handling or cutting through inflated vesicles can rupture them and invite infection.