Appearance
M. dichotoma is a colonial hermatypic coral with a calcareous endoskeleton. They form colonies up to 60 cm wide, but clumps of colonies may be several meters across. They initially build as encrusting coral, adhering themselves to hard substrate. The encrusting formations further develop into other growth forms, such as lace-like, leaf-like blades, and box-work. What growth form an individual develops into is highly dependent on the depth and location of growth as well as on the turbidity of the water in a given location. More fragile structures, such as lace-like, succeed better in deeper, less turbulent waters, whereas box-work forms are able to better succeed in harsher environments. As in other hermatypic corals, part of the metabolism of fire corals relies on zooxanthellae. Symbiotic zooxanthellae give M.

