Trumpet Coral

The trumpet or "candy cane" coral is an LPS with a branching (phaceloid) skeleton, each polyp sitting at the tip of its own tube. The polyps are round; in the middle is a neon green mouth, surrounded by brown-green stripes formed by thick septa. The branches split in two over time and the colony spreads as a lush cluster. During the day the polyps are slightly inflated, and at night short tentacles open.

Its hardiness, quick recovery and ease of fragging make it one of the best choices for a first stony coral. The correct spelling is Caulastraea; the spelling "Caulastrea" is also common in the hobby. Its trade is subject to CITES Appendix II; most of those sold are aquacultured frags, so choose those. The similar-looking Caulastrea curvata is now placed in the genus Astraeosmilia.

It lives in the Indo-West Pacific on sheltered reef slopes with partly sandy bottoms; it sometimes forms large single-species stands exceeding five meters. Being used to calm, slightly turbid water explains why it is comfortable under moderate light and moderate flow in the aquarium.

• Light: Moderate, about 75–200 PAR. It also survives in low light, but the green color brightens under moderate light.
• Flow: Moderate and indirect. The polyps should move gently; detritus should not collect between the branches.
• Placement: The middle or lower zone of the rockwork. Leave space around it, as the colony spreads sideways.
• Water parameters: Salinity 1.024–1.026, KH 7–10 dKH, calcium 400–450 mg/L, magnesium 1250–1350 mg/L. It is tolerant; regular calcium and KH supplementation speeds up growth. Nitrate 2–10 mg/L and phosphate 0.03–0.1 mg/L are suitable.

It is photosynthetic; light is its main source of nutrition. When mysis, brine shrimp or fine-grained LPS food is given once or twice a week to the tentacles that open after the lights go out, new branches appear more often. Feeding each polyp individually with a pipette is the most efficient way.

It is a peaceful LPS. It opens short tentacles at night but has no long stinging "sweeper" tentacles; even so, tissue loss can occur at the border with a coral it touches directly. About 5 cm of space between it and its neighbors is enough. It is itself harmed by aggressive species such as Euphyllia, Galaxea and Favites.

Dwarf angelfish and some hermit crabs may pick at the polyps. It has no problems with most reef fish.

It is one of the easiest LPS to propagate. One or several branches are cut at the base with coral cutters and glued to a frag plug. Single-polyp frags also survive and split in two within a few months. The mother colony recovers quickly after cutting.

• Polyps shrinking: Strong flow, too much light or going unfed for a long time are common causes.
• Tissue recession at the base of the branches: Detritus or algae collecting between the branches can cause it; blow the detritus away regularly with a pipette.
• Fading color: Seen after a sudden increase in light; increase the light gradually.