Identification
Morphological Characteristics:
Colonies exhibit a branching form that varies from broadly spreading to tightly clustered. Basal branches are large, with diameters up to 4 cm; main branches are more slender, approximately 1.5 cm in diameter. Colony height is less than 30 cm. Lateral polyps show variations in morphology and size even on the same branch, and are arranged irregularly, sometimes in rows. These polyps are tubular or cone-shaped, with a calyx diameter of approximately 1 mm. Axial polyps protrude up to 3 mm, with a diameter of 2.4 – 3.8 mm, and a top opening diameter of 1.0 – 1.5 mm. Living specimens display diverse colors, including shades of green, brown, yellow, and pale yellow.
Biology and Ecology
This species can inhabit environments with both wave action and calm water, but it is most commonly found in areas with high wave activity, particularly in open ocean environments.
Distribution
Within Vietnam:
Quang Ninh (Ha Long Bay, Co To Archipelago), Hai Phong (Bach Long Vy Island), Quang Ngai (Ly Son Island), Khanh Hoa (Nha Trang Bay, Truong Sa Archipelago), Ninh Thuan (Hon Thu Island), Ba Ria – Vung Tau (Con Dao), Kien Giang (An Thoi).
Worldwide:
Warm waters of the Indian Ocean and Western Pacific (from Madagascar in the west to the Marshall Islands in the east, and from Papua New Guinea in the south to Okinawa Island in the north).
Value
This species plays an important role in reef formation in shallow, open marine environments. It can be used to create handicrafts, decorate aquariums, and produce lime and cement.
Conservation Status
Current Status:
The species is currently being overexploited. It is a sensitive species, susceptible to mass mortality when environmental conditions change. Its distribution area is shrinking due to coastal pollution.
Assessment:
VU A1a,c B2b+3d (Vulnerable).
Conservation Measures
- Prohibit the harvesting of live coral for handicrafts and construction materials.
- Protect island forests and upstream forests.
- Prohibit fishing on reefs using toxins or explosives.
- Prohibit bottom trawling near coral reefs.