Mushroom Corals (Discosoma / Rhodactis / Ricordea)

Taxonomy & Identity

Mushroom corals, technically corallimorphs, are soft-bodied relatives of stony corals and anemones. They lack a calcium carbonate skeleton, making them flexible and hardy. Three main genera dominate the hobby: Discosoma (common mushrooms), Rhodactis (hairy mushrooms), and Ricordea (flower mushrooms). All are excellent beginner corals.

Natural Habitat & Distribution

Mushroom corals are found throughout tropical oceans. Discosoma and Rhodactis occur primarily in the Indo-Pacific, while Ricordea includes R. florida from the Caribbean and R. yuma from the Pacific. They typically inhabit shaded areas, reef rubble zones, and lower reef slopes with moderate to low light levels.

Morphology & Growth Forms

All mushrooms have a flat, disc-shaped body attached to substrate by a short column. Discosoma have smooth to slightly textured surfaces. Rhodactis feature prominent pseudotentacles giving a hairy or fuzzy appearance. Ricordea have distinctive bubble- like vesicles covering their surface. Colors span the entire rainbow with countless patterns and combinations.

Lighting Requirements & Spectrum

• Intensity: Low to moderate
• Target PAR: 30–150

Mushrooms generally prefer lower light conditions and may bleach or shrink under intense illumination. They're ideal for shaded areas where other corals won't thrive. Ricordea yuma tolerates slightly higher light than other mushrooms. Blue spectrum lighting enhances fluorescence in many specimens.

Flow Requirements & Patterns

• Intensity: Low
• Type: Gentle, indirect

Low flow is preferred for most mushroom species. Strong currents cause them to curl, detach, or fail to fully expand. Just enough water movement to prevent detritus accumulation is ideal. Mushrooms often do well in naturally lower-flow areas of the tank.

Nutrient Dynamics & Water Chemistry

Mushrooms are extremely tolerant of varying water conditions and actually thrive in nutrient-rich environments where other corals struggle. They're often the last corals to show stress when water quality degrades. This hardiness makes them perfect for beginners or challenging tank locations.

Feeding Biology & Symbiosis

Mushrooms contain zooxanthellae and photosynthesize effectively. They can also capture and consume food, with larger Rhodactis specimens capable of engulfing surprisingly large prey items including small fish.

• Mysis and brine shrimp
• Finely chopped meaty foods
• Coral pellets and powders
• Will capture and eat small fish and shrimp (Rhodactis)

Feeding isn't necessary but can accelerate growth and reproduction. Rhodactis are particularly voracious feeders.

Common Diseases, Pests & Predators

• Generally very disease resistant
• Occasional mushroom-specific infections (rare)
• May be picked at by certain angelfish or butterflyfish
• Can detach and drift if stressed

Mushrooms are remarkably pest and disease free. Their main issue is that stressed specimens may detach and drift around the tank, potentially landing in undesirable locations or dying if they end up in high-flow areas.

Compatibility & Placement

Mushrooms can be aggressive, spreading rapidly and overgrowing other corals. Some species release toxins that inhibit neighboring coral growth. They're best given their own area or kept on isolated rocks. Large Rhodactis can eat small fish.

• Best zone: Lower tank, shaded areas
• Give space: Contain on their own rocks when possible
• Warning: Will overgrow slower corals

Fragging Techniques

Mushrooms frag very easily. Methods include cutting through the disc (pieces regenerate into new mushrooms), cutting the column, or simply encouraging detachment. Place pieces in low-flow containers with rubble until they attach. They also reproduce naturally through splitting and budding.

Aquacultured Strains & Trade Names

Popular varieties include Bounce Mushrooms (with bubble-like vesicles), "Jawbreaker" Rhodactis, Blue Discosoma, "Superman" and "Yoda" Rhodactis, and Ricordea florida in orange, green, and multicolored morphs. Rare bounce mushrooms can command thousands of dollars.

Difficulty Rating & Summary

Difficulty: Beginner

Mushroom corals are among the hardiest and most forgiving corals available. Their tolerance of poor water quality, low light requirements, and easy propagation make them ideal for beginners. While not technically true corals, they add beautiful color and movement to reef aquariums and often thrive where other corals fail.