Saint Thomas mushroom (Discosoma sanctithomae) care guide

Group
Corals
Other names
Discosoma, Mushroom coral, Disc anemone
Family
Discosomidae
Origin
Tropical western Atlantic, including the Caribbean
Water
saltwater
Temperature
22–26°C
pH
8.1–8.4
Hardness
dKH 8–12
Care level
beginner
Reef safe
yes
Lighting
Moderate
Flow
Low to medium

Care

Discosoma sanctithomae is a Caribbean mushroom coral (corallimorph): a flat, round disc with a central mouth and a smooth or slightly bumpy surface, usually brown, green or blue. LiveAquaria's assorted mushroom listing covers this group (it names them Actinodiscus, formerly Discosoma) and is the source for the care below. Placement: low to middle of the rockwork in moderate light; place it lower if lighting is intense. It prefers low to medium flow. Water: about 22–26 °C, pH 8.1–8.4, dKH 8–12. Iodine and trace elements help. It is hardy and multiplies quickly. Mushrooms are not CITES-listed. Sources: LiveAquaria (liveaquaria.com/products/assorted-colored-mushroom-coral). Checked October 2026.

Diet

Partly photosynthetic; it also absorbs nutrients and takes micro-plankton or brine shrimp fed to each disc.

Breeding

Very easy. Mushrooms split by fission, bud from the base and move to new spots. Cut a disc through the centre or off the rock with a scalpel and hold it on rubble under mesh until it attaches.

Compatibility and tank mates

Semi-aggressive: it can sting and crowd out neighbours as it spreads, so give space from other corals and sessile invertebrates.

Last updated 8 October 2026. Community-edited care guide on Aquatic-Auctions.

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