Molecular assessment of Pocillopora verrucosa (Scleractinia; Pocilloporidae) distribution along a depth gradient in Ludao, Taiwan

It can be challenging to identify scleractinian corals from the genus Lamarck 1816 in the field because of their large range of inter- and intra-specific morphological variation that co-occur with changes in the physical environment. This task is made more arduous in the context of a depth gradient, where light and water current could greatly affect the morphology of the corallum. (Ellis & Solander 1786) in Taiwan was previously reported exclusively from shallow waters (40 m in depth) questions this bathymetric distribution. We used the mitochondrial open reading frame and the histone 3 molecular markers to investigate the vertical and horizontal spatial distribution of around Ludao (Green Island), Taiwan. We genotyped 101 -like colonies collected from four depth zones, ranging from 7 to 45 m, at three sites around the island. Of the 101 colonies sampled, 85 were genotyped as , 15 as and one specimen as an undescribed species. was found at all depths, while and the undescribed specimen were limited to 15 m depth. has a large bathymetric distribution around Ludao and could benefit from the refuge that the mesophotic zone offers. This study illustrates the difficulty of identifying corals in the field and emphasizes the relevance of molecular taxonomy as an important and complementary tool to traditional taxonomy for clarifying vertical and horizontal species distribution. Our results also illustrate the need in conservation biology to target species genetic diversity rather than just species diversity.