Bubble Coral (Plerogyra sinuosa) Propagation Guide

How to propagate Plerogyra sinuosa (bubble coral): deflate the grape-like vesicles, cut the meandering skeleton between heads, and manage its sweeper-tentacle sting.

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.