Caulastraea echinulata

Caulastraea echinulata is a colonial stony coral in the family Merulinidae, recognizable by its distinctive trumpet- or torch-like polyps that extend from tubular corallites, often displaying fleshy tentacles tipped in contrasting colors during the day. Like other scleractinians, it builds a calcium carbonate skeleton and hosts symbiotic zooxanthellae, which supply energy through photosynthesis while the coral supplements its diet by capturing zooplankton at night. As a reef-building species, it contributes structural complexity to reef habitats, offering shelter and substrate for other marine organisms.

The species occurs in shallow marine neritic waters across the Indo-Pacific, with recorded populations in Singapore, Malaysia, Indonesia, Vietnam, China, Taiwan, Japan, Australia, Palau, the Solomon Islands, Fiji, New Caledonia, American Samoa, and Mauritius. It typically inhabits reef flats and lagoons at shallow depths.

Its decline stems from a combination of pressures: coastal mining and quarrying degrade reef substrate, while fishing and harvesting activities directly remove colonies, often for the aquarium trade. Recreational activities, sedimentation from agricultural and forestry runoff, and untreated domestic wastewater degrade water quality. Habitat shifting linked to broader environmental change, disease, and competition from invasive or problematic native species add further strain.

Conservation efforts include the species' listing under CITES, which regulates international trade, alongside marine protected areas established across parts of its range that limit extraction and coastal development. Some regional reef monitoring and restoration programs also track coral health in areas where the species occurs.

Population trends are decreasing, and while no precise global population figures are available, the combination of ongoing habitat degradation and continued harvesting pressure suggests the species' conservation trajectory remains unfavorable without stronger enforcement of existing protections.