The corals of the genus Physogyra all display their tissue
in the form of bubbles. In fact, the most common names for these corals
are 'Grape Corals' and 'Pearl Corals' (Physogyra
Lichtensteini), although these species are often confused with members
of the Plerogyra genus which includes the
true 'Bubble Coral' (Plerogyra
Sinuosa).