Distribution of Deep-Water Scleractinian Corals in the Indian Ocean and Its Similarities and Differences with the Distribution in the Pacific Ocean

The aim of this article is to clarify the particular distribution of deep-water Indian Ocean scleractinian corals with respect to the location of the belts of the global oceanic conveyor. This study is based on the author's own and others' publications on the fauna of Indian Ocean corals; it ranks by depth the stations where these organisms have been found. It has been determined that a maximum of finds was obtained at a depth of 1-2 km, with the amount declining sharply at lower depths, and that the amount increases once more at a depth of 4-5 km. However, at lower depths, scleractinian corals are represented by just three species belonging to two genera. An asymmetrical spatial distribution of scleractinian corals at depths greater than 3 km was established, with a far greater number of stations in the western part of the ocean than in the east. This phenomenon is likely linked to the idiosyncracies of the circulation of both contemporary and Neogene water. Comparison of the fauna of Indian Ocean scleractinian corals at depths of 1-2 km with those of the Pacific, which have already been studied, shows that the Pacific features the greatest abundance of species, 109, while that of the Indian Ocean has 18 species.