Red Ultra Saint Thomas Mushroom

Red Ultra Saint Thomas Mushroom

Common Names: Red Ultra Saint Thomas Mushroom, Ultra Red Saint Thomas Mushroom, Red Saint Thomas Mushroom Coral
Scientific Name: Rhodactis sp.
 

Type: Corallimorpharian / Mushroom Coral
 

Identification

Red Ultra Saint Thomas Mushrooms are highly sought-after corallimorpharians known for their deep red to vibrant crimson coloration and large, fleshy mushroom-like appearance. Depending on the specimen, the oral disc may display contrasting shades, textured surfaces or subtle colour variations that become especially striking under reef LED lighting.

Although commonly called a mushroom "anemone", the Saint Thomas Mushroom is a corallimorpharian rather than a true anemone. Its impressive size, coloration and relatively hardy nature make it a popular choice for feature areas in reef aquariums.

 

Behaviour & Growth

Red Ultra Saint Thomas Mushrooms can become quite large when fully expanded and may gradually spread by budding or splitting under favourable conditions.

They are generally peaceful but should be given adequate space because their fleshy body can shade neighbouring corals. As they grow, they may occupy considerably more space than their initial frag or specimen size suggests.

 

Compatibility & Caution

Reef Safe: Yes, with caution.

Saint Thomas Mushrooms are generally suitable for reef aquariums, but they should not be placed directly beside delicate corals. Their large body can shade surrounding corals, and direct contact may cause irritation.

Allow sufficient space around the specimen for future growth and expansion.

 

Care Level

Easy to Moderate

Red Ultra Saint Thomas Mushrooms are relatively hardy when maintained in a mature aquarium with stable water parameters. They are a good choice for reef keepers looking for a colourful, substantial soft-bodied coral.

 

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, consistent and stable conditions are more important than chasing exact numbers.

Lighting

 

Low to Moderate

Red Ultra Saint Thomas Mushrooms generally perform well under low to moderate reef lighting. Stronger lighting can be used, but specimens should be acclimated gradually when moved into higher-intensity systems.

Their red coloration can appear particularly vibrant under blue and violet-heavy reef lighting.

 

Water Flow

Low to Moderate, Indirect Flow

Provide gentle to moderate flow that allows the mushroom to expand naturally. Avoid strong, direct flow that causes the coral to remain contracted or prevents it from attaching securely.

Good circulation also helps prevent detritus from accumulating on its fleshy surface.

 

Feeding

Red Ultra Saint Thomas Mushrooms are photosynthetic and receive a significant portion of their energy from their symbiotic zooxanthellae. They can nevertheless benefit from supplemental feeding.

Suitable foods include:

• Mysis shrimp
• Finely chopped marine seafood
• Frozen reef foods
• Fine coral foods
• Quality particulate reef foods

Feed approximately 1–2 times per week, adjusting according to the size and condition of the specimen. Avoid overfeeding.

 

Placement

Place the mushroom on stable rockwork or another secure location where it can attach naturally.

Provide generous spacing from neighbouring corals. A small specimen can expand dramatically once comfortable, so avoid judging its required space solely by its size when purchased.

Once established, minimize unnecessary movement and allow it time to settle into its preferred position.

 

Tank Mates

Compatible with most peaceful reef fish and invertebrates. It can be housed alongside soft corals, LPS and SPS when sufficient spacing is provided.

Because Saint Thomas Mushrooms can become large and potentially reproduce by splitting, monitor their growth so they do not eventually shade or crowd neighbouring corals.

 

Fun Fact

The Ultra Red colouration can become exceptionally vivid under blue reef lighting, making these mushrooms a fantastic feature coral for a mixed reef or dedicated mushroom collection. Their appearance can also change dramatically between their relaxed, fully expanded form and their tightly contracted state.

 

Tropic N Reef Recommendation: Red Ultra Saint Thomas Mushrooms are an excellent choice when you want a large, dramatic red feature coral that is relatively easy to maintain. Give it low-to-moderate lighting, gentle indirect flow and plenty of room to expand, and avoid placing it immediately beside prized corals.