DNA Barcoding of the Soft Coral, Clavularia inflata, Shows Two Major Groups across Indonesian Coral Reefs

Abstract

Clavularia inflata was first described from Ternate Island, Indonesia in 1896 and later reported appeared from Japan and Taiwan in 1953.Clavularia (Blainville 1830) soft corals exhibit complex morphological traits that are difficult to differentiate, thus complicating their identification. DNA barcoding has been envisioned and actively pushed as a credible method for assigning unidentified specimens to known species by comparison to a molecular reference data database. DNA barcoding is an important tool to support the management of biological resources, one of which are soft corals. As soft corals are among the species that are difficult to identify morphologically, DNA barcoding data are very valuable for identifying them. Thus, the purpose of this study was to use molecular methods to confirm the identity of 25 colonies taken from 13 Indonesian coral reef sites (Anambas, Natuna, Tanjung Lesung, Kepulauan Seribu, Madura, Kangean, Bontang, Lombok, Manado, Wakatobi, Morotai, Kon, and Maluku Tenggara Barat (MTB)) and putatively identified as C. inflata. All specimens were identified as C. inflata molecularly using the mitochondrial DNA mtMuts gene. The results from this study can enrich the information base for barcoding of soft corals elsewhere because the samples were taken across a range of nearly 4000km throughout Indonesia archipelago. Although a comparison of the nucleotide base chains to Genbank data indicates that the samples belong to a single species, two clades in the phylogenetic tree and data from the Automatic Barcode Gap Discovery (ABGD) indicate that there are two major groups of C. inflata in Indonesia, implying cryptic species.