Dana, 1846Characters: Colonies are massive, columnar, laminar, branching or encrusting and are usually less than one metre across. They are commonly mixtures of these growth-forms. Corallites are separated into groups by ridges. Colour: Usually brown or blue. Similar species: Porites rus, which tends to form branches whereas P. monticulosa tends to be massive or form plates. Habitat: Shallow reef environments. Abundance: Common in the western Indian Ocean.