Acropora gemmifera

Acropora gemmifera is a coral species with a broad distribution, including areas such as the Gulf of Aden, the Red Sea, and the central Indo-Pacific. It is also present in the southwest and northern Indian Ocean, southeastern Asia, Australia, and reaches as far as northwestern Hawaiʻi. This coral is typically found on upper reef flats and slopes that are exposed to the elements, usually at depths between 1 and 15 meters, though it can be found as deep as 50 meters. The coral forms colonies with thick, tapering branches. Each branch ends with a single axial corallite, and the radial corallites are neatly arranged in rows. The colors of Acropora gemmifera can vary, including hues of blue, brown, cream, or purple, with the tips of the branches often being white or blue. The corallites are generally dark grey with white edges, and some specimens in the Indian Ocean are noted to have yellowish axial corallites. In terms of reproduction, Acropora gemmifera is hermaphroditic. It releases mature gametes into its coelenteron, which are then spawned through the mouth. The resulting zygote develops into a planktonic planula larva, which eventually undergoes metamorphosis before settling on a substrate. The species is currently listed as Endangered on the IUCN Red List, facing threats from global coral reef decline, rising sea temperatures, and other environmental pressures.