Cactus Coral

Care at a glance

Overview

A generally calm stony coral that still carries sweeper tentacles reaching several inches at night, so give it real space from its neighbors rather than crowding it in. It does best under medium light, around 100 PAR is a reasonable target, since pushing it under intense lighting too fast can bleach the tissue. It wants medium to high flow to keep its folded plates clear of detritus and to encourage the tighter, more upright growth form. Feeding is optional: it has small mouths but will take minced mysis or rotifers, and it is one of the more forgiving stony corals for a keeper moving up from softies and LPS into SPS.

In the wild

Pavona cactus grows on shallow Indo-Pacific reef flats and lagoons, including Fiji, Tonga, the Solomon Islands, and the Great Barrier Reef, typically in water less than 15 meters deep. It forms thin, upright plates that branch and fold back on themselves like a stack of chips, or a flatter encrusting mat, depending on how much flow it grows in. In the aquarium it does best under medium light, around 100 PAR, with medium to high flow, set on the lower to middle rockwork away from the most intense top-of-tank light.

Good to know

Pavona sits in the family Agariciidae alongside the lettuce and leaf corals, and its corallites lack distinct walls, instead sharing ridged septa that connect neighboring polyps into a continuous, flower-like surface. Pavona cactus builds its skeleton into thin, contorted vertical plates under higher flow, or spreads as a low encrusting sheet where movement is gentler, so colonies of the same species can look very different from tank to tank. It carries photosynthetic zooxanthellae like other reef-building corals and gets most of its energy from light rather than from capturing food.

Did you know

A single Pavona cactus colony can grow two completely different shapes depending on water movement, folding into tight, upright chip-like plates in strong flow while a neighboring patch of the same species spreads into a flat encrusting mat in calmer water on the same reef.

Related species

• 

  Potato Chip Coral

  Pavona decussata

  11.8 in (30 cm)20 gal (75 L)75–81°F (24–27°C)

• 

  Leaf Coral

  Pavona frondifera

  9.8 in (25 cm)20 gal (75 L)75–81°F (24–27°C)

• 

  Lettuce Coral

  Pavona varians

  9.8 in (25 cm)20 gal (75 L)75–81°F (24–27°C)

• 

  Maldives Pavona

  Pavona maldivensis

  7.9 in (20 cm)20 gal (75 L)75–81°F (24–27°C)

• 

  Shoulderblade Coral

  Pavona clavus

  19.7 in (50 cm)26 gal (100 L)75–81°F (24–27°C)

• 

  Porkchop Coral

  Pavona duerdeni

  23.6 in (60 cm)26 gal (100 L)75–81°F (24–27°C)