The paliform lobes, visible through the tissues, are large and broad in protected environments but much smaller in colonies occupying exposed positions.

[6] In a rather different forms of sexual reproduction, it has been found that on some occasions, the eggs and developing larvae are brooded in the maternal polyps.

In its tissues it contains symbiotic unicellular photosynthetic organisms that provide nutrients and energy for the coral host.

In Thailand in 1995, in a reef flat dominated by C. aspera, there was a mass bleaching event caused by high water temperatures.

They hypothesized that the corals "remembered" a previous bleaching event caused by solar radiation and had built in some defences on the affected side.

This demonstrated that the previously affected areas had developed coping strategies and had a "memory" of at least ten years.