St. Thomas Mushroom Care Guide
Discosoma sanctithomae is a hardy Caribbean mushroom corallimorph with a bumpy disc, well suited as a beginner reef invertebrate.
Compiled by Aquairi from published sources · Published · Updated
Overview
Discosoma sanctithomae is a Caribbean mushroom corallimorph distinguished by a bumpy, warty disc surface. It is available in green, blue, brown and red. As a member of the order Corallimorpharia, it is related to both corals and anemones, is disc-shaped and produces large amounts of mucus.
Taxonomy
- Family: Discosomatidae (WoRMS: Discosomidae)
- Genus: Discosoma (Rüppell & Leuckart, 1828)
- Scientific name: Discosoma sanctithomae
- Note: WoRMS lists this name as a synonym of Rhodactis osculifera
Habitat
This corallimorph occurs on Caribbean reefs. It absorbs nutrients produced by symbiotic zooxanthellae in its tissues and gathers particles from the water, so photosynthesis is its primary energy source.
Tank requirements
- Minimum tank volume: 40 L
- Temperature: 24-26 °C (75-79 °F)
- Salinity: 1.024-1.026 SG
- pH: 8.1-8.4
- dKH (alkalinity): 8-11
- Lighting: low to moderate; avoid over-illumination
- Flow: low; best extension in near-stagnant water
Diet
It relies mainly on photosynthesis via zooxanthellae, supplemented by absorbing dissolved nutrients and capturing fine particles. Heavy direct feeding is generally unnecessary.
Propagation
Mushrooms heal well from cutting and grow quickly, making them suitable for early propagation attempts. Reattaching cuttings is the main difficulty; secure each piece to substrate that is then glued into place because mushrooms can detach and move.
Compatibility
It is reef-safe and compatible with most reef fish and invertebrates. Butterflyfish that nip soft-bodied corals should be avoided.
Discosoma sanctithomae (St. Thomas Mushroom) Propagation & Fragging Guide
Overview
Discosoma sanctithomae is a Caribbean mushroom corallimorph, often called a mushroom anemone but biologically a corallimorpharian. Reef Builders notes that taxonomically this form has also been treated as Rhodactis osculifera, reflecting ongoing debate; regardless of placement, husbandry and propagation follow the same mushroom approach. Corallimorphs are essentially stony corals without a calcium carbonate skeleton and are hardy, beginner-friendly reef invertebrates.
Reproductive Mode
Like other mushroom corallimorphs, D. sanctithomae reproduces mainly asexually in the hobby. Reef Builders documents asexual reproduction via pedal laceration in Discosoma and notes that established Discosoma spread and multiply quickly. Sexual reproduction is broadcast and pelagic and is not part of normal hobby propagation.
Asexual Propagation / Fragging
Hobbyists frag mushrooms by deliberate cutting. Reef Builders reports that Discosoma heal well from cutting and grow quickly afterward, which makes them an ideal first propagation attempt. The hardest part is reattaching the cuttings, because neither rubber bands nor glue hold the soft tissue directly.
The workable method is to set each cutting onto a small piece of substrate and glue that substrate to a larger rock in the aquarium; the mushroom attaches itself as it heals. Pieces shed naturally through pedal laceration also drift, settle and regrow into new polyps without intervention.
Conditions for Propagation
Reef Builders recommends lower light (around 100 PAR or less) and minimal flow, observing that the best polyp extension is reached in near-stagnant water. Low flow additionally lets dislodged polyps settle and re-anchor, raising the success rate of fragging cuttings.
Sexual Reproduction
Sexual reproduction occurs by broadcast spawning into open water with pelagic larvae, a process not reproduced in closed aquaria. In practice, propagation of D. sanctithomae in the hobby is entirely asexual.