1.   Another difference is that the polyps of leather corals have eight tentacles, rather than the six found in hard coral polyps.

2.   The tropic sun is the power behind this feast, fueling both the flotillas of tiny drifting plants and the microscopic algae that dwell inside each coral polyp.

3.   In addition to coral polyps several coralline algae which also produce limestone skeletons are considered important in the building and consolidation of coral reefs.

4.   Increased turbidity reduces the penetration of sunlight, thus inhibiting photosynthesis in primary producers such as the symbiotic algae of coral polyps.

5.   It has been threatened, in the past, by outbreaks of the predatory crown of thorns starfish, which can kill large areas of coral polyps.