Molecular phylogeny of some coral species from the Persian Gulf.

As evolutionary relationships among some coral species still remain unclear, studies on unstudied area such as the Persian Gulf (PG), as part of the western Indo-Pacific, may reveal a better understanding of phylogenetic positions and relationships of corals. In the present study, the phylogenetic relationships of eight common coral species (Favites pentagona, Platygyra daedalea, Cyphastrea microphthalma, Siderastrea savignyana, Pavona decussata, Pavona cactus, Goniopora columna, and Goniopora djiboutiensis) collected from two Iranian Islands were compared with the congeneric sequences from the Indo-Pacific (IP) using rDNA region. The result shows that some coral species which were hitherto considered as representatives of widespread species from IP are related to distinct lineages. Further, it appears that morphological convergence between the taxa leads to an underestimation of the real coral species diversity in the PG. The current study is the first attempt to investigate the phylogenetic position of coral species from the PG in comparison to their counterparts from the IP. As conservation planning hinges on the identification of species, taxonomic revisions have to be undertaken in order to obtain a more reliable picture of coral species diversity in the PG.

Health status of corals surrounding Kish Island, Persian Gulf.

Corals in the Persian Gulf exist in a harsh environment with extreme temperature and salinity fluctuations. Understanding the health of these hardy corals may prove useful for predicting the survival of other marine organisms facing the impacts of global climate change. In this study, the health state of corals was surveyed along belt transects at 4 sites on the east side of Kish Island, Iran. Corals had a patchy distribution, low colony densities and species diversity, and were dominated by Acropora, Porites, and Dipsastrea. We found chronic sedimentation on corals, a high prevalence of old partial mortality, abundant bioeroders, and overgrowth of corals by sponges and bryozoans. These are all signs indicating suboptimal environmental conditions for coral reefs. Four types of tissue loss lesions consistent with disease were found: Porites multi-focal chronic tissue loss, Porites peeling tissue loss, Porites focal chronic tissue loss, and Dipsastrea focal sub-acute tissue loss. Overall disease prevalence was 3.6% and there were significant differences in prevalence among the 3 most abundant coral genera. Acropora was numerically dominant within transects yet showed no signs of disease, whereas Porites had a 14% disease prevalence, indicating differential susceptibility to disease among genera. Other coral lesions included pigmentation response in Porites associated with algae invasion or boring organisms, sponge overgrowth, and mucus sheathing in Dipsastrea. The Persian Gulf region is understudied, and this represents one of the first quantitative surveys of coral health and disease on these reefs.