Acan Echinata

Acanthastrea echinata is the most commonly seen Acanthastrea species on tropical reefs. The colony spreads over rock or forms a dome; the round corallites are covered by fleshy tissue that forms thick, concentric rings. In the wild most colonies are brown, gray or green, but brightly colored selected forms are also found in the trade. Unlike the Acan lord, it is still in the genus Acanthastrea. Its trade is subject to CITES Appendix II; choose an aquacultured frag.

• Light: Low to moderate, about 50–150 PAR.
• Flow: Low to moderate and indirect.
• Placement: The lower zone of the rockwork; on a horizontal surface it grows in a spreading form.
• 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, but makes good use of food with the feeding tentacles that open at night. Feeding mysis or fine-grained LPS food once or twice a week fills out the tissue.

It does not put out long "sweeper" tentacles, but it can digest a coral it touches with its mesenterial filaments; leave 5–10 cm between it and its neighbors. Do not place it within reach of aggressive LPS. Dwarf angelfish and hermit crabs may pick at the fleshy tissue. Cutting is done between the corallite walls with a diamond-blade saw.