Tubastrea faulkneri and T. coccinea are easily recognized by their orange cups. The dendroid colonies are very lightweight and are ahermatypic, meaning they do not contribute significantly to reef structure. Tubular and very apparent corallites rise off a generally ball-like main skeletal body, and are covered with a skin-like orange coenosteum. Septa are prominent and obvious, especially in fully contracted specimens. The polyps are large and extend mostly at night. These corals have thick and sharply tapered tentacles, with the nematocyst buds and batteries visible as opaque spots on the translucent yellow to orange tentacles. A prominent central mouth is apparent, and completes an overall polyp one that truly typifies the "textbook" polyp formation. Source: http://www.reefs.org/library/aquarium_ne...
Open reef, under overhangs, or in areas of high nutrients (zooplankton).
Not sure if this is T. coccinea or T. faulkneri . Appreciate help on ID. Spotted on a night dive at a depth of about 6 m.