Galaxea fascicularis reaches 5 m colony diameter. Hard coral in dome or plate shape with tightly packed tubular corallites (like stars forming galaxy). Polyps with characteristic long white, green or pink translucent tentacles, visible day and night (except under stress). Known for exceptional aggressiveness: long stinging filament tentacles (acontia nematocysts) attacking neighboring corals to conquer space. Lives from 2 to 20 m on Indo-Pacific reefs. Listed NT. Detailed polyp photo subject.
