Colonies of A. agaricites have several different habits of growth, but usually occur in encrusting sheets with irregular projections or are leaf-like or plate-like. New colonies are usually encrusting, but vertical lobes and sheet-like projections begin to develop when the colonies are still quite small. The growth form seems to be partially linked to the movement of water in the vicinity and the depth. Horizontal plates normally have corallites on both sides while vertical forms have corallites on only one side. The corallites are arranged in long meandering rows, but a few are single, with sharp-pointed ridges between them. Each one has up to 36 septa and a central spongy columella. This coral is a brown or purplish-brown colour. A. agaricites is susceptible to bleaching. In 1997, during an El Niño Southern Oscillation year with raised seawater temperatures off the coast of Brazil, this coral was the most affected coral species, with 80% of the individual colonies being bleached. When the water temperature returned to more normal levels, the colonies were slow to recover, but six months later, neither bleached nor dead colonies were found. Learn more about Lettuce Coral