Regional specific approach is a next step for setting evolutionary‐based conservation priorities in the scleractinian corals

Coral reefs contribute highly to marine biodiversity and provide ecosystem services to millions of people living around the world. The main reef builder is the zooxanthellate scleractinian coral (reef-building coral) with extant 837 species. These corals face extinction risk at present by threats such as bleaching, disease and predation by crown-of-thorns seastar and also due to anthropogenic disturbances. Carpenter et al. (2008) assessed the conservation status of 845 coral species (827 scleractinian and other non-scleractinian corals) using the International Union for Conservation of Nature (IUCN) Red List Criteria, showing 32.8% of coral species listed in elevated risk of extinction. This imminent risk of coral extinction shows a pressing need of conservation action and also setting conservation priorities because of limited resources available for conservation. The evolutionary distinct and globally endangered (EDGE) metric (Isaac et al., 2007), which measures species’ relative contributions to phylogenetic diversity as evolutionary distinctiveness (ED), and global endangerment using the data provided by IUCN Red List Categories, was first applied to 1293 coral species (including 837 reef, 456 nonreef corals) to identify the most endangered lineages (Huang, 2012). This approach generally requires a large set of phylogenetic data on the extant species and is not applicable to poorly studied animals, such as many marine invertebrates. In the current issue of Animal Conservation, Curnick et al. (2015) investigated the effects of increased phylogenetic knowledge on the accuracy of ED scores over time using corals as a case study because the phylogenetic information of corals has been increasing since 2000 (Kerr, 2005), especially in 2008 and later. In particular, they calculated ED scores based on molecular-based phylogenies from 2008 to 2013. Their study demonstrated that ED scores from the most recent and largest phylogenies of corals showed the highest correlation with those from the ‘reference’ tree, based on the full-coverage species level supertree (Huang, 2012; Huang & Roy, 2013). Interestingly, ED scores from coral expert opinion also showed high correlation, when used as a basis for imputing scores for missing species, concluding that ED score imputation would be useful for assessing conservation priorities for other poorly studied animals. Taxonomic revisions of several genera or families in the scleractinian corals have progressed dramatically in recent years, with the molecular phylogenetic data having been used as the basic information. These recent taxonomic revisions sometimes gave us unexpected results. The most surprising one is that Psammocora explanulata and Coscinaraea wellsi in the family Psammocoridae were merged with the genus Cycloseris in the Fungiidae (Benzoni et al., 2012). Also, genera in the former ‘Faviidae’ were totally revised taxonomically (e.g. Budd et al., 2012). Thus, taxonomic status of coral families, genera and species are instable, especially for species that are not analyzed yet molecularly. Therefore, imputing ED scores for missing species in molecular data might have some risks to overestimate the species rank if the taxonomic situation of the target animals is debated or instable such as with corals. The most recent molecular phylogenetic trees of corals used in Curnick et al. (2015) were inferred using an incomplete supermatrix analysis using seven mitochondrial genes, which means that several species have missing data in each marker. At present, we do not have complete gene data set for all zooxanthellate coral species, so this approach is one of the best ways to rank coral species for conservation priorities. Considering the rapid progress of coral taxonomic revisions at present, all missing data for at least one or two markers, such as cytochrome oxidase subunit I, could be obtained within a few years if coral scientists in the world can cooperate together. Then, it will be interesting to recalculate ED and EDGE scores using complete data set of DNA for all species. While worldwide conservation priorities of corals have been estimated well, as a next step, we will need conservation priorities for corals to be locally or regionally specific because more endemic species of corals would be apparent bs_bs_banner