Ten Coral

About

Ten Coral (Madracis kirbyi) grows across a wide stretch of the Indo-West Pacific, turning up from shallow water down to around 60 meters in a variety of reef settings. It seems particularly at home in turbid conditions where water clarity is lower than ideal, which hints at a degree of adaptability not all corals share. Colonies take on several different forms, submassive, encrusting, nodular, or columnar with club-shaped tips, so the same species can look quite different depending on where and how it grows. The corallites sit tightly packed together with angular outlines, and what really distinguishes this coral is the consistent presence of ten septa, each fused to a solid conical columella at the center. The surface of the tissue between corallites has a fine, spiny texture. Coloration tends toward mottled browns and reddish-browns across the coenosteum, while the oral discs are green or white. Like many corals, the tentacles come out mainly after dark, so daytime viewers mostly see the skeletal structure rather than any polyp activity. In the aquarium it needs high light and strong flow to do well, putting it in intermediate territory. Not the most demanding SPS coral out there, but not a beginner pick either.