Beautiful coloured Starfish | ©Lynne Tuller (Mombasa, Kenya)
This starfish is Pentaceraster mammillatus, a species in the family Oreasteridae (order valvatida), characterized by having interadial spines green with orange tubercles .
Sometimes this sea star is called Common Knobbed Starfish. The specific name mammillatus refers to the rows of nipple-like protuberances that cover the surface of the animal and give it a studded or armored appearance.
The known distribution of this starfish covers the Indian Ocean and the Red Sea. In 2008 was documented its presence in Singapore waters .