Niche breadth and divergence in sympatric cryptic coral species ( spp.) across habitats within reefs and among algal symbionts.

While the presence of morphologically cryptic species is increasingly recognized, we still lack a useful understanding of what causes and maintains co-occurring cryptic species and its consequences for the ecology, evolution, and conservation of communities. We sampled 724 corals from five habitat zones (the fringing reef, back reef, and fore reef at 5, 10, and 20 m) at four sites around the island of Moorea, French Polynesia. Using validated genetic markers, we identified six sympatric species of , most of which cannot be reliably identified based on morphology: (42.