Purple-tipped finger coral, Montipora digitata
(Phylum Cnidaria, Class Anthozoa, Order Scleractinia. See Overview of Cnidarian Diversity)
Montipora digitata exists in several color forms. This so-called purple-tipped variety is mostly greenish brown in color, but the growing branch tips have a pale lavendar-purple color under proper lighting.
This fast-growing small polyped stony coral has densely packed polyps that give the surface of the colony a velvety appearance. The skeleton of this coral is very brittle, and fragments break off readily. As is the case with most small-polyped stony coral species, if fragments land and stay stationary in suitable locations, on a hard substrate with adequate light and water flow, they will grow onto the substrate and firmly attach in a matter of weeks. In faster growing species such as this, subsequent colony development is rapid.