Saint Thomas Mushroom Coral

Saint Thomas Mushroom Coral

Common Names: Saint Thomas Mushroom, St. Thomas Mushroom, St. Thomas Mushroom Anemone
 

Scientific Name: Rhodactis sp.
Type: Corallimorpharian
 

Availability: Available while supplies last — colour, pattern and size may vary between individual specimens.

 

Identification

Saint Thomas Mushrooms are large, eye-catching corallimorpharians known for their fleshy, mushroom-like appearance and vibrant colours. They can develop a broad oral disc with textured or slightly raised surfaces and may display shades of green, brown, purple, blue, pink or combinations of these colours.

Despite their common name, they are not true anemones and are generally considered mushroom corals. Their fleshy appearance and relatively undemanding nature make them an excellent choice for reef aquariums.

 

Behaviour & Growth

Saint Thomas Mushrooms are generally peaceful but can become quite large as they mature. They can expand significantly from their original size and may eventually shade or overgrow nearby corals.

They can reproduce by budding or splitting, allowing a single colony to gradually develop into multiple mushrooms under suitable conditions.

Because of their potential size and growth, provide adequate space around the specimen when placing it in the aquarium.

 

Compatibility & Caution

Reef Safe: Yes, with caution.

Saint Thomas Mushrooms are generally compatible with reef aquariums but should not be placed directly against more delicate corals. Their large fleshy body can shade neighbouring corals, and contact with nearby corals may result in irritation.

Give them plenty of room to expand and grow.

 

Care Level

Easy to Moderate

Saint Thomas Mushrooms are relatively hardy once established and can tolerate a range of aquarium conditions. They are suitable for both newer reef keepers with stable systems and experienced reef aquarists.

Recommended Parameters:

• Temperature: 24–27°C (75–81°F)
• Salinity: 1.024–1.026 specific gravity
• pH: 8.0–8.4
• Alkalinity: 7–11 dKH
• Calcium: 400–450 ppm
• Magnesium: 1250–1400 ppm
• Nitrate: Approximately 2–15 ppm
• Phosphate: Approximately 0.03–0.15 ppm

As with other reef inhabitants, stability is more important than maintaining an exact number.

 

Lighting

Low to Moderate

Saint Thomas Mushrooms generally do well under low to moderate reef lighting. If introduced into a system with significantly stronger lighting, acclimate the coral gradually to prevent stress or bleaching.

Their colouration can vary depending on the intensity and spectrum of lighting.

 

Water Flow

Low to Moderate, Indirect Flow

Provide gentle to moderate circulation that allows the mushroom to move naturally without being constantly blasted by direct flow.

Avoid strong, direct flow that causes the coral to remain tightly contracted or prevents it from maintaining its normal shape.

 

Feeding

Saint Thomas Mushrooms are photosynthetic and obtain a significant portion of their energy through their symbiotic relationship with zooxanthellae.

They can also benefit from supplemental feeding, particularly in systems with lower nutrient levels.

Offer small amounts of appropriately sized foods such as:

• Mysis shrimp
• Finely chopped seafood
• Reef-specific frozen foods
• Fine coral foods

Feed approximately 1–2 times per week, depending on the size and condition of the specimen.

 

Placement

Place Saint Thomas Mushrooms on rockwork or a stable location where they can attach securely.

Allow plenty of room for expansion. Avoid positioning them immediately beside valuable SPS or other sensitive corals.

Once established, avoid frequent movement, as mushrooms can take time to attach and settle into their preferred location.

 

Tank Mates

Compatible with most peaceful reef fish and invertebrates. They can be kept with a wide variety of soft corals, LPS and SPS provided sufficient space is maintained.

Be aware that their eventual size and ability to reproduce can make them surprisingly dominant in a small reef aquarium.

 

Fun Fact

Saint Thomas Mushrooms can dramatically change their appearance depending on their environment. A specimen may contract tightly when disturbed and then expand into a large, fleshy disc once comfortable, sometimes becoming several times larger than its original contracted size.

 

 

Tropic N Reef Recommendation: Saint Thomas Mushrooms are an excellent choice for reef keepers looking for a large, colourful and relatively hardy coral. Give them moderate lighting, gentle flow and plenty of growing room, and avoid placing them too close to prized neighbouring corals.