Biodiversity and biogeography of marine, reef-forming red algal order Corallinales from western Pacific Ocean – BIOCARRA

Specimens are collected by SCUBA or reef walking at low tide in various areas including Taiwan, New Caledonia, Papua New Guinea, French Polynesia in the Pacific Ocean and Maldives, Iles Eparses and La Réunion in the Indian Ocean. The specimens are sorted out in the lab, manually labeled, fresh fragments are taken for storage in silicate gel and formalin solution in sea water for DNA and histological analysis, respectively. Then, specimens are dried for reference collections and are housed in the partner’s laboratories. Molecular analyses are done using different markers for four genes; the histological studies are conducted under microscope on thin sections obtained from decalcified tissue. The species are delineated based on genetic results and morphology/histology work. The phylogenetic analysis is done considering all the new sequences and additional sequences coming from GenBank and unpublished data from the partners.

Almost 500 different specimens have been collected in the Coral Triangle from Taiwan to New Caledonia including Papua New Guinea but also from South Pacific and Indian Ocean. These collections are housed in the partner’s institutes. Nowadays, around 1,000 sequences have been generated using various markers from four genes (nuclear:SSU and LSU; mitochondrial:cox1; plastidial: psbA). Phylogenetic analyses based on all the available sequences have shown several lineages on which histological effort will be focused. The taxonomical studies are partially done on the genus Mastophora and the Mesophyllum/Phymatolithon complex from the western Pacific and almost finished on Mesophyllum from Taiwan. Studies of Hydrolithon/Porolithon, Neogoniolithon and Lithophilloids are ongoing. The combined approaches have already shown numerous new taxa, some of them already described and publishable.

The perspectives at the mid-term period are to continuing the prospection in New Caledonia and Indonesia to enlarge the basic knowledge of this group, which appears to be richer than expected using molecular tools in particular. Two campaigns are already scheduled in New Caledonia for sampling in the Chesterfield reefs located off the grand Terre at mid-distance to Australia, and in the Ile des Pins in the south. Applications for sampling permits in Indonesia are in progress. Molecular and histological analyses will be carried out along with phylogenetic studies on the available material. Biogeographic analyses will be started when all the taxonomical work is achieved.

Results are currently analyzed and the first publications will be submitted by the end of 2015.

The coral reefs are important ecosystems consisting of the richest biodiversity in all the oceans around the world, and provide abundant biological resources for food and recreation of the human kinds. Currently, in tropical areas, coral reefs are suffering from worldwide depletion due to unsustainable fisheries, coastline development, and also impact of global warming. It has been pointed out by many recent coral reef researches that the current status of critical functional groups needs to be reassessed urgently. In particular, little information about biodiversity of the reef-forming crustose coralline algae is known. Therefore, we propose to investigate the species diversity and distribution of the reef-forming, crustose coralline algae occurring in the western Pacific Ocean by a combination of DNA sequencing analyses and comparative morphological observations with an emphasis on the cystocarp development in their sexual life history within a 3-year period. We will investigate the well-developed coral reefs of the coasts of Taiwan, New Caledonia and Indonesia.In this study, four main areas will be investigated: (i)Species diversity survey: The systematics of the coralline algae is in a continuous state of flux and phylogenetic relationships among taxa are for the most part unresolved thus the goal is to investigate offshore and nearshore assemblages of the coralline algae and include both in-depth resolution of modern baseline measures of biodiversity and establishment of molecular protocols to measure the biodiversity of reef-forming coralline algae. Representative species of the major families and tribes are present in Taiwan, New Caledonia and Indonesia (Bali) and these three sites will be compared. (ii) To infer the phylogenetic relationships of the reef-forming coralline communities in the western Pacific Ocean: the coralline community of Taiwan, New Caledonia and Indonesia shares many common species and genera according to current knowledge. A joint assessment of phylogenetic relationships among the reef-forming coralline species of both sites will help us to understand the evolutionary histories and mechanism of speciation of different coralline lineages. (iii)To assess the biogeographic patterns of the reef-forming coralline algae in the western Pacific Ocean in order to understand their evolutionary histories. (iv)To provide baseline information on the key component of reef-forming coralline algae in coral reefs, and share our findings to the region as a way to strengthen and highlight the value and importance of the marine cooperative research.