Identification
Colony morphology is intermediate between a branching, clustered form and a corymbose form (caespito-corymbosa). The main branches are thick, reaching up to 25 cm, and bear numerous short side branches, often of equal length. Lateral polyps are tubular, with a circular, slightly flared mouth. Axial polyps have a diameter of 2-3 mm with a pore diameter of 0.8-1.4 mm. Living specimens are typically brown, purple, yellow-brown, or pale green.
Biology and Ecology
This species belongs to the reef-building corals and is distributed in shallow coastal waters, both in sheltered and exposed areas.
Distribution
- Vietnam: Widely distributed on coral reefs from the Gulf of Tonkin to the Gulf of Thailand, and in the Spratly and Paracel Islands.
- Global: Found in warm waters of the Indian Ocean and the Western Pacific (from the Maldives in the West to the Marshall Islands in the East and from southern Papua New Guinea and the Great Barrier Reef in the South to Okinawa and Amami in the North).
Value
Plays an important role in reef formation in shallow reef zones. It can be used to create handicrafts, decorate aquariums, and produce lime and cement.
Conservation Status
The species is currently overexploited. It is a sensitive species, prone to mass mortality when the environment changes. Its distribution area is shrinking due to coastal environmental pollution, particularly from turbid water and low salinity.
IUCN Red List Category: VU A1a,c B2b+3d.
Conservation Measures
Listed in the Vietnam Red Book (1992, 2000). Prohibiting the exploitation of live coral for handicrafts and construction materials, protecting forests on islands and upstream forests, prohibiting fishing on reefs with toxins and explosives, and prohibiting bottom trawling near coral reefs.