Seriatopora hystrix - Thin birdsnest coral
Based on this link for ID, but as most of my coral pics, always tentative sp
''Seriatopora hystrix'' is a species of colonial stony coral in the family Pocilloporidae. It forms a bushy clump and is commonly known as thin birdsnest coral. It grows in shallow water on fore-reef slopes or in sheltered lagoons, the type locality being the Red Sea. It is native to East Africa, the Red Sea and the western Indo-Pacific region. It is a common species and the International Union for Conservation of Nature has assessed its conservation status as being of "least concern".