Mushroom Coral

Overview

General Description: Mushroom corals are solitary or colonial corallimorpharians with fleshy, disc-shaped bodies. They are valued for hardiness, vivid colors, and their ability to thrive in lower-light areas where many stony corals struggle.

Appearance: A broad oral disc surrounds a central mouth and attaches to rock with a pedal base. The surface may be smooth, bumpy, covered in bubble-like vesicles, or lined with hair-like tentacles.

Notable Characteristics: They lack a stony skeleton, can inflate dramatically, may move or detach when unhappy, and range from smooth Discosoma to textured Rhodactis and bubble-covered Ricordea.

Natural Habitat

Native Distribution: Found across tropical and subtropical seas; Discosoma and Rhodactis are widespread in the Indo-Pacific, while Ricordea includes Caribbean and Indo-Pacific species.

Natural Reef Habitat: Shaded reef faces, lagoons, rubble zones, crevices, lower reef slopes, and other protected hard substrates.

Depth: Variable, from shallow protected reefs to deeper or shaded zones depending on species.

Natural Lighting: Generally low to moderate, though some shallow-water species receive stronger light.

Natural Flow: Usually gentle to moderate, indirect water movement rather than forceful surge.

Other Habitat Notes: Many occupy nutrient- and plankton-accessible areas with shade, rock crevices, or protection from intense flow.

Aquarium Placement

Recommended Placement: Place low to mid-level on stable rock with indirect flow. Start new or unidentified mushrooms lower and move gradually if needed.

Space Requirements: Allow at least 3-6 inches around most specimens and more around large, fast-spreading, or strongly stinging Rhodactis.

Rock/Sand Placement: Rock attachment is preferred. A loose mushroom can be placed in a low-flow rubble cup until it attaches; avoid gluing tissue directly.

Attachment Method: Secure the rock or frag plug beneath the mushroom. For unattached specimens, use a shallow container with rubble and loose mesh rather than cyanoacrylate on the animal.

Orientation: Place the oral disc upward on a horizontal or gently angled surface where it can fully expand without collecting debris.

Distance From Other Corals: Typically 3-6 inches; use greater separation from SPS, zoanthids, and other corals easily stung, shaded, or overgrown.

Other Placement Notes: A mushroom island can limit spreading. Leave room for full inflation, which may make the animal much larger than it appears when contracted.

Lighting

Lighting Requirement: Low to moderate for most types. Ricordea and brightly colored morphs may need moderate light, while many Discosoma tolerate shade.

PAR Range: Approximately 40-150 PAR; 50-100 PAR is a conservative starting range, then adjust for genus and behavior.

Spectrum Considerations: A balanced reef spectrum with blue and violet light supports photosynthesis and fluorescence; spectrum cannot compensate for excessive intensity.

Acclimation Requirements: Begin in lower light and increase exposure over one to several weeks, particularly after shipping or when moving from dealer lighting.

Signs of Too Much Light: Shrinking, persistent contraction, paling or bleaching, gaping, moving into shade, or detaching from the substrate.

Signs of Too Little Light: Excessive stretching, dull or browned color, reduced growth, and persistent expansion toward the light; some healthy low-light mushrooms naturally expand widely.

Water Flow

Flow Requirement: Low to moderate indirect flow that keeps the disc clean without folding or lifting it.

Preferred Flow Pattern: Broad, gentle, random movement rather than a narrow direct jet.

Signs of Excessive Flow: The disc remains folded or contracted, edges lift, the animal moves, or it detaches and blows around the aquarium.

Signs of Insufficient Flow: Detritus or mucus settles on the disc, algae grows nearby, or the animal remains coated after feeding or stress.

Water Parameters

Temperature: 75-80°F (24-27°C)

Salinity: 1.024-1.026 specific gravity (about 32-35 ppt)

pH: 8.1-8.4

Alkalinity: 8-11 dKH, maintained consistently

Calcium: 400-450 ppm

Magnesium: 1250-1400 ppm

Nitrate: Approximately 2-15 ppm; avoid abrupt nutrient starvation and chronically excessive levels

Phosphate: Approximately 0.03-0.10 ppm; stable measurable phosphate is often preferable to zero

Other Relevant Parameters: Ammonia and nitrite should remain at 0 ppm. Maintain good gas exchange and avoid untested trace-element dosing.

Parameter Sensitivity: Common mushrooms are fairly tolerant, but Ricordea and stressed or freshly cut animals can react strongly to salinity, temperature, alkalinity, or light changes.

Stability Requirements: Stable conditions are more important than chasing exact numbers; change salinity, nutrients, and lighting gradually.

Feeding & Nutrition

Photosynthetic: Yes. Symbiotic dinoflagellates supply much of their energy under suitable lighting.

Natural Feeding: Captures plankton, fine organic material, and small prey on the oral disc while also absorbing dissolved nutrients.

Target Feeding: Optional. Place an appropriately sized food on the disc with flow reduced briefly; remove uneaten food and do not force-feed a closed animal.

Recommended Foods: Mysis pieces, finely chopped marine flesh, enriched brine shrimp, copepods, and fine coral foods sized to the individual.

Feeding Frequency: Optional once weekly or every one to two weeks; large Rhodactis may accept food more readily than smooth Discosoma.

Benefits of Feeding: Can support growth, recovery, and reproduction in receptive specimens, particularly larger or more predatory varieties.

Special Nutritional Requirements: No routine special supplement is required beyond suitable light, stable water chemistry, and balanced nutrients.

Growth

Growth Rate: Highly variable: some Discosoma and Rhodactis spread quickly, while Ricordea and premium morphs may grow slowly.

Growth Pattern: New individuals form by division, budding, or pedal laceration; detached tissue may establish elsewhere.

Maximum Colony Size: Colonies can cover large rock sections, while individual discs range from roughly an inch to several inches or more depending on species.

Space Requirements: Leave open rock for expansion and use an isolated island if the variety reproduces rapidly.

Overgrowth Concerns: Fast-growing mushrooms can shade, sting, or crowd coral bases and may be difficult to remove from porous rock or crevices.

Aggression

Aggression Level: Moderate overall, with substantial variation; some large Rhodactis are strongly aggressive and may capture small fish or invertebrates.

Sweeper Tentacles: No long LPS-style sweepers, but the expanded disc and marginal tentacles can contact neighbors.

Chemical Warfare: Can release mucus and organic compounds; activated carbon, skimming, and regular water changes help in mixed reefs.

Stinging Ability: Mild to strong depending on type. Direct contact can damage SPS, zoanthids, and other sensitive corals.

Required Spacing: At least 3-6 inches for typical specimens; allow more for large Rhodactis or rapidly multiplying colonies.

Corals to Avoid Nearby: Keep away from SPS bases, delicate encrusters, zoanthids, and any slow-growing coral that could be touched, shaded, or overgrown.

Compatibility

Fish Compatibility: Compatible with most reef-safe fish. Large elephant-ear-type Rhodactis may occasionally trap very small, weak, or resting fish.

Invertebrate Compatibility: Usually compatible with reef-safe snails and shrimp, though large predatory mushrooms may capture small invertebrates and crabs may irritate the disc.

Coral Compatibility: Works in mixed reefs with adequate spacing and growth control; either the mushroom or a more aggressive neighbor may damage the other on contact.

Potential Predators: Some butterflyfish, angelfish, filefish, nudibranchs, and other coral-eating animals may nip or consume tissue.

Potential Irritants: Strong flow, sediment, algae, vermetid mucus, crabs walking across the disc, nearby stingers, and fish repeatedly pecking or perching.

Fragging & Propagation

Difficulty: Easy to moderate; common mushrooms heal readily, while Ricordea and stressed animals require cleaner technique and closer monitoring.

Propagation Method: Cut the disc through the mouth into sections, divide a naturally splitting animal, or collect attached offspring produced by pedal laceration.

Tools/Method: Use gloves, eye protection, a clean scalpel, forceps, a separate container of aquarium water, and a rubble cup with loose mesh. Do not glue freshly cut soft tissue directly.

Healing: Keep fragments in low-to-moderate light and gentle flow on clean rubble. They may take days to weeks to heal, form a mouth, and attach.

Special Risks: Fragments can develop infection, melt, detach, or drift into unwanted locations; cut animals may produce heavy mucus.

Safety Considerations: Wear waterproof gloves and eye protection, cover cuts, prevent splashes, disinfect tools, and wash hands. Mushroom corals are not known for the palytoxin hazard associated with some zoanthids, but their mucus can still irritate skin and eyes.

Health & Common Problems

Tissue Recession: May follow physical damage, infection, excessive light or flow, severe parameter swings, or a neighboring sting. Remove the cause and isolate healthy tissue if recession advances.

Bleaching: Usually caused by excessive light, heat, or rapid change. Reduce stress gradually and maintain stable water conditions.

Polyp Retraction: Temporary contraction is normal after disturbance. Persistent shrinking or failure to inflate suggests flow, light, chemistry, predation, or infection problems.

Pests: Flatworms, nudibranchs, algae, and other hitchhikers may irritate tissue. Inspect, dip appropriately, and quarantine new specimens.

Diseases: Bacterial tissue breakdown or rapid melting can follow injury or poor conditions; diagnosis should consider recent changes and visible damage.

Signs of Stress: Persistent contraction, gaping mouth, excessive mucus, bleaching, torn tissue, failure to attach, wandering, detachment, or rapid tissue loss.

Common Keeper Mistakes: Using too much light or direct flow, gluing living tissue, placing aggressive varieties too close to corals, overfeeding, and failing to contain fast-spreading colonies.

Recovery Considerations: Correct the underlying issue gradually, move only when necessary, use gentle flow, remove decaying tissue or uneaten food, and isolate healthy portions if tissue loss continues.

Beginner Suitability

Beginner Friendly: Yes for most common Discosoma and Rhodactis; moderate for Ricordea and premium or recently cut specimens.

Why: Many tolerate lower light, do not require target feeding, and handle a useful range of reef conditions.

Major Challenges: Genus-specific needs, excessive light or flow, wandering or detachment, controlling reproduction, and spacing aggressive large varieties.

Before You Buy

Important Considerations: Identify the genus or trade type when possible, inspect for damage and pests, and ask whether it is attached, feeding, and accustomed to the seller's light.

Space: Allow for full inflation and future offspring; isolate fast-growing colonies if spread would be a problem.

Lighting: Match the seller's conditions initially and acclimate gradually, especially with Ricordea or brightly colored morphs.

Flow: Choose a protected location with broad low-to-moderate flow and no direct jet.

Aggression: Larger Rhodactis and dense colonies need more spacing than small smooth mushrooms.

Parameter Stability: Add to a cycled aquarium with stable salinity, temperature, alkalinity, and balanced nutrients.

Long-Term Growth: Plan whether you will allow a mushroom garden or remove offspring before they spread into the main reef.

Species-Specific Information

Anything important that does not fit above: Mushroom coral is a broad trade term rather than one species. Discosoma are often smooth and very tolerant; Rhodactis may be hairy, larger, faster-growing, or more predatory; Ricordea have prominent vesicles and may prefer cleaner, more stable conditions. Bounce, jawbreaker, and other trade morph names describe appearance, not a separate universal care category.