Care guide · Marine · corals

Discosoma mushroom corals

Discosoma

Genus level

Discosoma nummiforme — an example within this genus guide; traded forms may differ. Photo: Emőke Dénes · Source · CC BY-SA 4.0Resized and compressed; no cropping or colour changes.

Discosoma are disc-shaped corallimorphs often sold as mushroom corals. They are not stony corals and do not form a hard reef-building skeleton. Different species and colour forms share the trade name, so this guide remains at genus level. Many common aquarium forms are relatively approachable, especially in a quiet position with modest light. Their easy reputation must not obscure their ability to spread, detach and occupy other corals' space. A separate manageable rock is often more practical than a position among slow-growing stony corals. This guide considers light, flow, growth and neighbours together, without assuming identical exact requirements for every disc sold.

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At a glance

Identification level: Genus level
Coral group: Corallimorph / mushroom
Difficulty: Easy
Growth and pruning: Moderate
Temperature: 24–26 °C
Specific gravity (SG at 25 °C): 1.025–1.026 SG
pH: 8.1–8.3
Alkalinity: 8–9 °dKH
Calcium: 400–450 mg/L
Magnesium: 1250–1350 mg/L
Light requirement: Low
Flow requirement: Low, Low to moderate
Position: Low, Shade
Aggression: Semi-aggressive
Supplementary feeding: Optional

Water values are reef-care guidance, not proven species limits. PAR describes only the stated culture experience; stability and gradual acclimation remain important.

About this coral

A broad oral disc sits on an attaching foot. Its surface may be smooth, textured, striped or spotted; colour alone does not identify the species. Rhodactis and Ricordea are also sold as mushrooms but do not automatically belong under this guide. The photo illustrates an identified Discosoma example. Unproven exact sizes, lifespans and survival boundaries are not assigned to every trade specimen.

Natural habitat

Discosoma includes species from different tropical marine regions. One origin or depth cannot reliably describe the genus. Aquarium specimens usually attach to hard substrate and can use sheltered reef areas. Ask about the cultured colony's recent conditions. Provide light without unexpected intense exposure and gentle movement past the animal.

Aquarium and layout

Prefer a separate rock where expansion can be followed. The open disc should not touch vulnerable neighbours. A low site can work but must not collect sand and debris. A loose specimen needs safe attachment away from pump intakes. No fixed minimum volume is supported for this broad genus; manageable growth and stability matter more than the size of the purchased frag.

Water conditions

Lacking a hard skeleton does not make water quality unimportant. Maintain stable tropical marine conditions and monitor salinity and temperature. Calcium and alkalinity additions follow whole-reef consumption, not the mushroom's presence alone. Measure before correcting. Nutrients in the water are different from rotting food remains. No universal nitrate or phosphate limits are invented for the diverse genus.

Lighting and acclimation

Low to moderate lighting suits many familiar aquarium forms, but is a placement direction rather than an exact PAR prescription. Ask about previous conditions and acclimate new specimens. A strong peak can occur even low beneath a lamp; a ledge may conversely shade too heavily. Assess steady expansion, intact tissue and growth. A larger stretched disc alone does not prove ideal lighting.

Water movement

A quiet position avoids continuously folding the disc or dislodging it, while circulation must still remove waste. Do not aim a pump at the foot or disc. Investigate flow, light, damage and water if detachment occurs instead of repeatedly returning it unchanged. A separate low-flow site with small suitable stones may support reattachment while retaining water exchange.

Feeding

Photosynthetic symbionts provide an important nutritional contribution. Some forms take small supplementary particles, but targeted coral food is not automatically necessary. Observe actual transport to the mouth and ingestion; movement near food alone proves little. Do not force growth through larger portions or leave remains on the disc. Generic coral powder requires species and application evidence before recommendation.

Growth and behaviour

A Discosoma can move slowly and leave pieces of its foot that develop into new animals; division also occurs. One purchase may gradually occupy a larger surface. Monitor the edge of its rock and small discs appearing among neighbours. Removal becomes harder deep within the layout. Choose manageable space before overgrowth creates a problem.

Aggression and spacing

A mushroom without conspicuous long sweepers is not automatically a harmless touching neighbour. Expansion can cover another coral or occupy its space. Keep living surfaces separate and assess the fully open disc. Variable species and growth forms prevent a defensible universal distance. Allow for new discs too, and investigate contact or shade when a neighbour's tissue recedes.

Keeping with fish

Assess interest in tissue and physical disturbance. A dwarf angelfish may nip corallimorphs; a general reef label is no guarantee. Foraging fish may take offered particles, while sand sifters may cover low discs. Use supported species relationships and retain a way to move a problem fish or separate rock. Robustness does not mean unlimited tolerance of repeated nipping.

Keeping with corals

A separate rock makes separation from slow-growing LPS and SPS easier. Do not let young discs advance into a stony coral's base. Higher branches may later alter lighting below, while mushrooms can overgrow low frags. In mixed reefs also consider chemical interactions and maintenance. Conditional compatibility means manageable coexistence, not a safe shared carpet.

Other invertebrates

Snails, shrimp and crabs are not uniform categories. A passing small grazer may cause brief closure, whereas an opportunistic crab may inflict deliberate damage. Loose discs are especially vulnerable to being moved. Assess exact marine identity and behaviour. Existing freshwater shrimp and snails are not alternatives; unsupported pairings remain unknown rather than automatically suitable.

Propagation and fragging

Natural spread often provides an attached young animal that can be moved with its holder. Do not tear a foot from sharp rock or glue living tissue. Cutting is not routine maintenance; let an experienced grower assess propagation. Protect hands and eyes from mucus, keep loose material out of pumps and allow injured or recently transported animals to recover first.

Possible problems

Persistent shrivelling, detachment, slimy disintegration or strong bleaching needs investigation. Check local flow, recent light increases, salinity and injury. Daily retraction differs from continuing tissue loss. Algae or pest treatments may harm other invertebrates; do not treat on one ambiguous sign. Record changes and seek experienced advice for rapid deterioration. Even an approachable animal can be lost in unsuitable conditions.

Keeping with other species

Care products

No sufficiently supported match to a specific existing care product has been established for this coral. Follow the feeding and care chapters; an absent product card does not mean feeding or measurements are unnecessary.

Sources & review

This care guide draws on several specialist sources and was last checked on 9 October 2026.

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