Identification:
Colonies exhibit a shrub-like form with morphology that varies complexly depending on the environment: sometimes small, hemispherical with thick branches in areas of strong wave action, and at other times an irregular bush-like form with main axes and slender branches in areas with less wave action or deeper water. This species is distinguished from other species in the genus by the absence of true verrucae (wart-like projections). Main branches either have polyps arranged contiguously (cerioid) or have underdeveloped secondary branches arranged irregularly, which are considered as verrucae. The mouth openings have a diameter of 0.7 – 1.5 mm. Living specimens are usually uniformly pink, purple, red, or yellowish-green; the branch tips are usually lighter in color.
Biology, Ecology:
Belongs to the reef-building coral group, found from the lower intertidal zone to a depth of 30 meters, tolerating both strong wave action and calmer waters. Primarily inhabits clear waters, but sometimes also found in less clear waters.
Distribution:
- Within Vietnam: Found on coral reefs from Quảng Trị (Cồn Cỏ Island) to Bà Rịa – Vũng Tàu (Côn Đảo), the southwestern islands (Thổ Chu, Nam Du, An Thới, Phú Quốc), and the Trường Sa and Hoàng Sa archipelagos.
- Worldwide: Tropical regions of the Indian and Pacific Oceans.
Value:
Used in handicrafts and for decorating ornamental fish tanks.
Status:
This species is currently being exploited unsustainably. It is a sensitive species and is prone to mass mortality when the habitat changes. The distribution area is shrinking rapidly due to coastal environmental pollution, particularly due to turbid water and low salinity.
Assessment:
VU A1c,d B2b+3d.
Conservation Measures:
Listed in the Vietnam Red Book (1992-2000). Prohibited from exploitation for handicrafts; protection of island and upstream forests to prevent terrestrial materials from negatively impacting the coral; prohibition of fishing on coral reefs using poisons and explosives; and prohibition of trawling near coral reef bases.