Also known as Brain Coral, Dented Brain, Greater Brain Coral, Sinuous Cup Coral.
Found over upper reef slopes of fringing reefs. Colonies are flat to dome shaped, walls are thick with a fleshy appearance and with a groove along the top.
Colours vary from red, grey, green with valleys and walls of contrasting colours.
They feed on plankton.
Width - 17cm
Depth - 0-40m
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. Ref: https://www.sealifebase.org/summary/Symphyllia-radians.html