The corals are the calcareous skeletons of polyps and the variability in shape is at least partly caused by the activities of horse mussels (Lithophaga spp.)

[4] It has been found that the size and proximity of the corallites varies depending on the amount of light incident on the coral, even over different areas of the same colony.

In less well lit positions, there are larger corallites and polyps with longer tentacles with greater food capturing ability.

The polyps contain symbiotic photosynthetic microalgae called zooxanthellae which, under good conditions, can obtain almost sufficient energy from sunlight for the coral's needs.

It also reproduces sexually, with both sperm and eggs being released into the water table in synchronized spawnings for external fertilisation.

[9] In common with other corals that contain zooxanthella, Galaxea fascicularis is likely to be stressed by climate change and the warmer waters it may cause.

Adverse effects of a rise in sea temperature may be more severe storms, a greater incidence of the El Niño-Southern Oscillation and more frequent outbreaks of coral disease.

[11] Galaxea fascicularis is a common species but takes about 8 years to reach maturity, making it difficult to assess its status except over long time scales.

These are commercially available for live feeding in the form of cysts which hatch within 24 hours, or as a dead, pasteurized product known as "Instant baby brine shrimp" (IBBS) with a long shelf life.