Identification Characteristics:
Colony branching, with dense, relatively straight branches typically 2 cm in diameter. Branching is irregular. Lateral polyps vary from tubular to immersed forms, with circular or oval mouths, of similar or varying sizes, interspersed. They can protrude up to 5 mm, but are small, with pore diameters of 0.6 – 1.2 mm. Axial polyps have a diameter of 3 mm, with an aperture of 0.6 – 1.2 mm. Living specimens are pale yellow, brown, or green, with white or blue branch tips.
Biology and Ecology:
Belongs to the reef-building coral group, concentrated in shallow coastal waters, in both sheltered and exposed areas.
Distribution:
In Vietnam: Quang Ninh (Ha Long, Co To), Hai Phong (Cat Ba, Bach Long Vy), central provinces from Quang Tri (Con Co) to Ba Ria – Vung Tau (Con Dao), the islands of the Southwest and the Truong Sa archipelago.
Worldwide: Tropical Indo-Pacific region (from the Red Sea, Madagascar to French Polynesia, and from Papua New Guinea to Okinawa and Amami, Japan).
Value:
Plays an important role in reef formation in shallow reef areas. Can be used for handicrafts, aquarium decoration, and building materials.
Status:
Currently overexploited. This is a sensitive species, prone to mass mortality with changes in its environment. Its distribution area is gradually shrinking due to coastal environmental pollution, particularly due to turbidity and low salinity.
Assessment:
VU A1a,c B2b+3d (Vulnerable).
Conservation Measures:
Prohibit the exploitation of live coral for handicrafts and building materials. Protect island forests and headwater forests. Prohibit fishing on reefs using toxins or explosives, and prohibit bottom trawling near coral reefs.