Pocillopora damicornis

Pocillopora damicornis is a stony coral that forms dense, rounded bushes of thin, irregular branches. The surface of the branches is covered with small bumps; when the polyps open, the colony looks slightly fuzzy. In the hobby, pink and green forms are found most often.

Recent genetic studies have shown that several very similar species (e.g. P. acuta) exist under this name. Many "damicornis" in aquariums may actually be one of these; there is no difference in terms of care.

It is known for fast growth and easy propagation; on the other hand, it is sensitive to rising temperature, shipping and sudden changes. Once acclimated, it is quite hardy. Trade in stony corals is subject to CITES Appendix II; choose an aquacultured frag.

• Pink Pocillopora: The most common form in the hobby.
• Green Pocillopora: Forms with a green body, sometimes with pink tips.

It lives over a very wide area from the Indo-Pacific to the Eastern Pacific, on shallow reefs, in lagoons and on reef flats. Where wave action is strong it builds short, stubby colonies; in calm lagoons, thinner and more open-branched ones. Guard crabs (Trapezia) live between the branches; these crabs protect the coral from predators such as sea stars.

• Light: Moderate to high light; roughly 150–300 PAR. A new frag should be kept under lower light for one to two weeks and moved up gradually.
• Flow: Strong, random flow. Detritus should not build up between the dense branches, but avoid a constant, direct pump outlet.
• Placement: The upper part of the rockwork, on a solid base, with 10 cm of space around it.
• Water parameters: Salinity 1.025–1.026, temperature 25–26.5°C and stable; above 28°C it bleaches quickly. KH 7–9 dKH, calcium 400–450 mg/L, magnesium 1250–1400 mg/L, nitrate 2–10 mg/L, phosphate 0.02–0.08 mg/L.

It is photosynthetic; it gets most of its energy from zooxanthellae algae. At night its polyps also capture small plankton. Fine powdered food, rotifers or copepods given in the evening once or twice a week support growth; this is not essential.

Its aggression is low, but it can irritate the tissue of corals it touches; leave at least 10 cm of space. Long-tentacled LPS (Euphyllia, Galaxea) and mushroom corals harm it.

The main thing to watch is its spreading: the colony regularly releases larvae (planulae), which can settle on rocks, glass and frag plugs and form new small colonies. Colonies in unwanted places should be scraped off while still small.

Dwarf angelfish may pick at the polyps. Trapezia crabs may arrive with wild colonies; they do not harm the coral but can pinch your hand.

Branch tips 2–3 cm long are cut and attached to a frag plug with gel glue. The cut tips heal quickly and the frag spreads onto the plug within a few weeks. Thanks to natural planula production, small colonies that appear on their own in the aquarium can also be removed together with the rock and propagated.

• Sudden bleaching: A rise in temperature or a sudden change in light; this genus is among the stony corals most sensitive to heat stress.
• Tissue loss from the base (STN): KH swings, detritus buildup or shaded inner branches.
• Uncontrolled spreading: If colonies from larvae are not removed while small, they settle at the bases of neighboring corals.
• Browning: Lack of light or high nutrients.