Goniastrea

Goniastrea is a genus of brain coral that grows in massive domes or cushions. In species such as Goniastrea retiformis the corallites are four- to six-sided and densely packed with shared walls; in species such as G. pectinata short, meandering valleys form. Its natural color is usually cream or light brown, and green and pink forms are also seen in the trade. Some species are hardy enough to be dominant on reef flats in places exposed at low tide. In stores it is often confused with Favites or Favia. Its trade is subject to CITES Appendix II; choose a maricultured colony or an aquacultured frag.

• Light: Moderate, about 100–250 PAR.
• Flow: Moderate and variable; detritus should not collect between the corallites.
• Placement: The middle zone of the rockwork.
• Water parameters: Salinity 1.024–1.026, KH 7–10 dKH, calcium 400–450 mg/L, magnesium 1250–1350 mg/L; nitrate 2–10 mg/L, phosphate 0.03–0.1 mg/L.

It is photosynthetic. Feeding fine-grained coral food or chopped mysis once a week to the short tentacles that open at night supports growth.

It extends tentacles at night and can digest a coral it touches with its mesenterial filaments; leave at least 10 cm between it and its neighbors. Keep it away from aggressive species such as Euphyllia and Galaxea. Dwarf angelfish and butterflyfish may pick at the tissue.