About Isopora palifera (Lamarck, 1816)
Isopora palifera (Lamarck, 1816) can grow in encrusting, massive forms, as well as produce columnar branches or parallel ridges of blade-like branches. The growth form it develops depends heavily on the amount of water movement at its growth site: it grows as an encrusting coral in strong currents or on the seaward side of a reef, and develops a more branching growth form in calm, still water conditions. Its branches measure 5 to 15 cm (2 to 6 in) in diameter and grow up to 20 cm (8 in) long. Each branch bears several axial corallites, which can reach up to 4 millimetres (0.16 in) in diameter. The radial corallites of this species are cylindrical, large, and grow close together or touching, and project up to 5 millimetres (0.20 in) out from the branches. Each radial corallite has a distinct, large, irregularly shaped opening near its tip. The color of this coral ranges from greenish to creamy or pale brown. This coloration comes from minute symbiotic dinoflagellates called zooxanthellae, which live within the tissues of the coral polyps. These photosynthetic algae produce organic compounds using sunlight, and the coral uses these compounds to meet part of its nutritional requirements. Fluorescent pigment granules are present in the coral's tissues, and these granules occur in higher concentrations in individuals that grow in high-light environments. Isopora palifera closely resembles Isopora cuneata, and the two species often have similar growth forms. However, I. cuneata is mostly found in more eastern parts of the Pacific, grows in shallower water, and has circular outline openings in its conical radial corallites. Isopora palifera occurs in the Indo-Pacific Ocean. Its range extends from South Africa and Madagascar to East Africa, Aldabra and Chagos, India, China, Japan, Indonesia and Australia. It is the most common coral species in the northern part of the Great Barrier Reef. As a reef-building coral, it is found subtidally on reef flats, edges, walls and slopes. The earliest fossil occurrences of Isopora palifera in the fossil record are from Papua New Guinea, dating to the Pliocene.
