Crown-of-thorns starfish substrates with their arms and, when offered a choice of substrates, tend to settle on coralline algae, which they will subsequently feed on. In the classic pattern for echinoderms, the bilaterally symmetrical larva is replaced by a pentamerously symmetrical stage at metamorphosis, with the latter's body axis bearing no relationship to that of the larva. Thus the newly metamorphosed starfish are five-armed and are 0.4–1 mm diameter. (Note the size of the tube feet relative to the size of the animal.) They feed on the thin coating layers of hard encrusting algae (coralline algae) on the undersides of dead coral
Calliaster baccatus reefs, mostly along the sandy margins. Its food and reproductive habits are unknown. Calliaster baccatus Calliaster baccatus, the cobbled starfish, is a species of starfish in the family Goniasteridae. The cobbled starfish is a large brick-coloured starfish which grows up to 200mm across. Its central area is covered with coarse granules and its upper arms are edged with large squarish tiles which may be smooth or have protruding granules. The tiles on the outer edged of the arms usually have protruding granules. It is only found from Lamberts Bay to Port Elizabeth on the South African coast, in 9-23m. It