Description

Also known as Bladder Coral, Branching Bubble Coral, Bubble Coral, Bubblegum Coral, Cateye Bubble Coral, Grape Coral, Large Polyp Stony Coral, Octo-bubble Coral, Pearl Bubble Coral, Pearl Coral, Round Bubble Coral, Rounded Bubblegum Coral.

Found in colonies, over deep walls and under overhangs, in murky waters, of protected coral and rocky reefs. The bubble tentacles are extended during the day, and hidden slightly by the longer tentacles when feeding during the night.
They feed nocturnally on zooplankton.
Length - 10cm
Depth - 0-40m
Widespread Indo-Pacific

Stony corals have hard stony skeletons, their polyps have six tentacles or are made up of multiples of six. These are usually nocturnal, however if the sky's are overcast, then many will feed during the day.
Generally the more robust corals life on exposed areas, while the smaller corals live in sheltered lagoons or deeper waters.
Stony corals are reef building corals and embedded in their flesh are thousands of minute single-celled marine plants called zooxanthellae which accounts for their colour.
These corals support a huge diversity of life, their main predator being the crown-of-thorns sea star. (edit) Ref: https://en.wikipedia.org/wiki/Plerogyra_sinuosa