Also known as Encrusting Sponge, Marine Sponge.
Found over coral and rocky reefs. Close too they look like mini volcano's! Pale cream or brown.
They feed on plankton.
Length - ?cm
Depth - 0-15m
Widespread Western Atlantic, Caribbean, 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. Ref: https://www.sealifebase.ca/summary/Halisarca-caerulea.html