Pocillopora is one of the most abundant and widely distributed coral genera, with a geographic range spanning the entire tropical Pacific and Indian Oceans as well as the Red Sea and Arabian Gulf. Across this enormous geographic range, Pocillopora is a major reef builder (second in importance and abundance only to Acropora) that can dominate a wide variety of habitats, including marginal environments occupied by only a few other coral genera. Despite the ecological importance of this genus, species boundaries remain poorly understood. Species identification is extremely challenging in many corals, and Pocillopora is often cited as a prime example. Around 40 species in the genus have been named, while approximately 14 are considered valid and one (P. elegans) is currently under consideration for protection under the US Endangered Species Act. However, the evaluation and conservation of coral species remains problematic due to taxonomic uncertainty (Brainard et al., 2011). The genus consists mostly of fast-growing “weedy species” that are highly susceptible to mortality from bleaching and predation, and, due to past patterns of regional extinction, are considered to be highly vulnerable (Van Woesik et al., 2012). P. damicornis is widely used as a model organism for research (a “lab rat”) because it is abundant, fast growing, and some varieties in some geographic regions brood planular (ciliated, free-swimming) larvae (Schmidt-Roach et al., 2012b). Several recent genetic studies have confirmed cryptic lineages (Flot et al., 2010; Pinzón and LaJeunesse, 2010; Souter, 2010; Schmidt-Roach et al., 2012a,b; Marti-Puig et al., in press), and a recent range-wide phylogeographic survey indicated that several genetic groups have highly limited geographic distributions (Pinzón et al., 2013).

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