Aussie Scolymia

Known in the hobby as "Aussie Scolymia" or simply "Scoly," this coral consists of a single large, round polyp. Its thick, velvety tissue often shows rings of color running from the center outward; there are red, green, orange and multicolored individuals. During the day the tissue inflates, and at night feeding tentacles open around the mouth. Its diameter usually does not exceed 10 cm.

For a long time it was known as Scolymia australis; a 2016 revision moved it to the genus Homophyllia. True Scolymia species live in the Atlantic and are rare in the trade; the large "Scolymia" from the Indo-Pacific is mostly Lobophyllia vitiensis. Its trade is subject to CITES Appendix II; it comes from regulated collection in Australia and, being a single polyp, cannot be propagated in the aquarium. When buying, choose an individual with untorn tissue that inflates readily.

• Rainbow Scoly: Expensive forms showing red, orange, green and blue rings together.
• Red or green Scoly: More common individuals dominated by a single color.

It lives on tropical and subtropical reefs and rocky bottoms along the coast of Australia. Because it is used to cooler water, it does not like temperatures above 25–26°C in the aquarium.

• Light: Low, about 30–100 PAR. In strong light the colors fade and the tissue does not inflate.
• Flow: Low and indirect. The tissue should ripple gently; strong flow tears it.
• Placement: On the sand or at the very bottom of the rockwork. It is easily injured if it falls from a height.
• Water parameters: Salinity 1.024–1.026, KH 7–10 dKH, calcium 400–450 mg/L, magnesium 1250–1350 mg/L. Sensitive to sudden changes. Nitrate 2–10 mg/L and phosphate 0.03–0.1 mg/L are suitable.

It is photosynthetic, but regular supplemental feeding is important for its long-term health. Twice a week, after the lights go out and the feeding tentacles have opened, place mysis, chopped shrimp or LPS food on top of the mouth. The mouth takes the food in within a few minutes; avoid overly large pieces.

It does not put out long sweeper tentacles, but at night it can digest a coral it touches with its mesenterial filaments. Leave about 10 cm of space between it and neighboring corals. Do not place it within reach of an elegance coral, open brain coral or plate coral on the sand.

Dwarf angelfish, large angelfish and hermit crabs may pick at the fleshy tissue. Bristle worms can gather on injured tissue.

Since it is a single polyp, it is practically never propagated in the aquarium; cutting it puts its life at risk. All individuals on the market are wild-collected. This is why its collector value is high and it is expensive; take care with correct placement and feeding so that it lives a long life.

• Tissue recession: Tissue loss starting at the edges is usually caused by too much light, starvation or high temperature.
• Torn tissue and brown jelly: A wound from shipping or a fall can turn into an infection; if noticed early, give the coral a coral dip in a separate container.
• Tissue not inflating: A sign of strong flow or a recent move.