Pavona Coral

Overview

Pavona, sold in the hobby as cactus coral, lettuce coral or potato-chip coral, is a small-polyp stony (SPS) coral - a colonial animal (a cnidarian), not a plant. Its polyps are among the smallest of any hobby coral, set in shallow valleys that give the skeleton a fine, ridged texture. Common aquarium species include Pavona cactus, Pavona decussata and Pavona maldivensis, which grow as thin upright plates, contorted folds or low encrusting crusts depending on species and conditions.

Origin & Habitat

Pavona is an Indo-Pacific genus, found from the Red Sea and East Africa through the Indian Ocean to the Pacific, with some species reaching the eastern Pacific. It occupies a wide depth range, from bright shallow reef flats to shaded slopes and lagoon walls, which explains its tolerance of moderate light in aquaria. Choose aquacultured frags rather than wild-collected colonies: stony coral collection is regulated and most species are listed under CITES Appendix II, and tank-raised pieces settle in far more readily.

Appearance

The classic look is a cluster of thin, vertical plates or ruffled fronds that fold over each other like leaves, with a matte, slightly velvety surface. Colours are usually understated compared with Acropora - forest and neon green, tan, brown, cream, pink and grey-blue - and the polyps are so small that the colony often reads as a solid textured sheet rather than a mass of individual mouths. Encrusting species instead spread as a flat, patterned crust over rock before lifting into plates.

Placement & Temperament

Pavona has no long sweeper tentacles, so it does not sting across open water, but it is not a passive neighbour either. It competes by growing over things: plates encrust across rock and lift into blades that shade and smother slower corals in contact with them. Leave clear rock around the colony and prune when it reaches a neighbour. It accepts a wide range of positions, from mid-rock to the lower third, which makes it useful for filling shaded gaps where fussier SPS will not colour up.

Tank & Water Conditions

A mature, stable reef system is still the baseline. Target salinity 1.024-1.026, temperature 24-27 C (76-82 F), alkalinity 8-11 dKH, calcium 400-450 ppm and magnesium 1300-1350 ppm. Pavona tolerates slightly higher nutrients than most SPS and can look better in a modestly fed tank than in an ultra-lean one, but it dislikes swings, especially in alkalinity. Consistency is the real requirement.

Lighting & Flow

This is one of the more light-flexible SPS corals, doing well anywhere from roughly 100 to 250 PAR. Bright light drives faster, more compact growth; moderate light gives looser, thinner plates and often deeper colour. Flow should be moderate and turbulent - enough to sweep detritus out of the folds between plates, which is where problems start, but not so strong that the thin blades are damaged. Stagnant pockets inside a dense colony are the most common cause of tissue loss.

Feeding

Symbiotic zooxanthellae supply most of its energy, so lighting is the main food source. The polyps are tiny and take only very fine particles; occasional broadcast feeding of microplankton or a fine reef blend supports growth but is not essential. Target feeding is impractical given the polyp size, and a clean, stable tank does more for a Pavona than any feeding routine.

Health & Growth

Pavona is genuinely one of the easier SPS corals and a good confidence-builder, but "easier SPS" is not the same as easy - it still needs mature water and stable chemistry. Growth is moderate to fast, and encrusting bases lock the colony to the rock quickly. Watch for algae or detritus building up in the crevices between plates, which leads to tissue recession from the inside out, and check flow if the interior of a colony starts to brown or die back. Bleaching usually follows a lighting change made too fast; browning usually means too little light.

Pros & Cons

Pros

• Tolerant of moderate light and slightly higher nutrients than most SPS
• No sweeper tentacles, and useful for filling mid- and lower-rock gaps
• Distinctive plate and frond texture unlike any branching stony coral

Cons

• Encrusts and overgrows slower neighbours in contact with it
• Detritus trapped between plates causes recession if flow is too gentle
• Colours are subtler than the bright morphs of branching SPS