ORA Micronesian Bubble Coral

Quick facts

Handling caution: Sharp skeletal septa can lacerate skin; sweeper tentacles can cause mild skin irritation

Identity

Also known as

Bubble coral; Pearl coral; Grape coral

Synonyms

Physogyra sp.

Environment

Saltwater

Native to

Indo-Pacific, Indonesia, Micronesia

Habitat

Reef slopes and lagoons with moderate light and gentle current, typically on sheltered substrate

Sourcing

Both

Conservation

Not Evaluated

Care

Care level

Easy

Coral type

LPS

Temperament

Aggressive

Growth form

Solitary

Adult size

2 – 8 in (5.1 – 20 cm)

Spread

10 in (25 cm)

Growth rate

Moderate

Placement

Low, Middle

Water

Temperature

76 – 80 °F (24 – 27 °C)

pH

8.1 – 8.4

dKH

8 – 12 dKH

Salinity

1.025 – 1.026 SG

PAR

75 – 150 PAR

Flow

Low

Light

Medium

Reef care

Nutrient preference

Medium

Alk/Ca uptake

Medium

Target feeding

Beneficial

Give it room

6 in (15 cm)

Colors

Green, Cream, Brown, Blue

Feeding & breeding

Diet

Photosynthetic

Foods

Frozen, Zooplankton, Coral food

Propagation

Fragging

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Care guide

Overview

Light green to beige bubbles swell over a ridged skeleton by day, deflating at night to reveal sweeper tentacles. This maricultured Micronesian strain suits reef tanks with gentle indirect flow and moderate light, placed low on stable rock with generous clearance from neighboring corals.

Care

Bubble coral is among the more forgiving LPS choices for someone moving beyond softies into stony corals. It tolerates a wide range of lighting but does best under low to medium PAR with gentle, indirect flow, since direct current will deflate the vesicles and stress the tissue. Give it a stable spot on the substrate or lower rockwork where it won't tumble, as its irregular skeleton makes secure mounting tricky.

Placement & acclimation

Acclimate to lighting gradually since PAR tolerance is broad but sudden changes can bleach or stress the tissue. Because the skeleton is heavy, irregular, and top-heavy when the bubbles inflate, glue alone often fails to secure it; use reef epoxy and mount as level as possible to avoid uneven physical stress on the polyp.

Feeding

Most nutrition comes from zooxanthellae, but occasional feeding of finely chopped meaty foods or small zooplankton improves growth and coloration. Target feed after the bubbles have retracted at night when the sweeper tentacles and mouths are more accessible, or feed just as the polyps begin to deflate at dusk. Avoid overfeeding directly onto the vesicles, since excess food can encourage tissue irritation.

Neighbors

Long sweeper tentacles emerge at night and can extend several inches beyond the inflated bubbles, stinging any coral within reach. Leave at least 5 to 6 inches of clearance on all sides, especially from other LPS and soft corals that lack strong chemical defenses. During the day the bubbles look harmless, which leads many keepers to underestimate how far the nighttime sweepers can travel.

Fragging

Fragging requires cutting through the skeleton to separate polyp-bearing sections, which is considered an expert-level task due to the risk of tissue damage and infection. Fragged pieces need time to heal and reattach tissue before handling or moving again.

Pests & problems

Rough handling during collection, shipping, or placement can tear the delicate tissue on the sharp septa, opening the door to bacterial or protozoan infection and brown jelly disease. Sustained direct flow that keeps the bubbles from inflating properly is a common but often misdiagnosed cause of decline, frequently mistaken for a water chemistry issue. Inspect new specimens closely for tissue damage before introducing them to the display.

Sources

1. MIMF Bubble Coral | Plerogyra sp. | ORA | Oceans, Reefs & Aquariums
2. ORA Micronesian Bubble Coral - Bulk Reef Supply
3. Bubble Coral Care - A Complete Guide - AquariumStoreDepot
4. Keeping the Bubble Coral | Coral Care | AlgaeBarn

Varieties in the catalog

ORA Pearl Bubble Coral