Yellow Tip Ritteri Anemone

Ritteri Anemone: The Expert-Only Host

The Ritteri Anemone (Heteractis magnifica), scientifically known by the current valid name, or the outdated synonym Radianthus ritteri, is one of the largest and most demanding sea anemones kept in the marine hobby. It is also widely known as the Magnificent Sea Anemone.

Native to the shallow, well-lit reef tops of the Indo-Pacific, this anemone is prized for its long, flowing, non-tapering tentacles and its often vibrant column (base) color, which can range from electric blue, purple, and red to deep orange and green. In the wild, it can reach an astounding diameter of over three feet, though captive specimens typically stay between 1.5 and 2 feet (45–60 cm).

The Ritteri Anemone is strictly for expert-level aquarists due to its large size, demanding requirement for extremely high, stable lighting and strong, turbulent water flow, and its tendency to be fragile following collection and shipping. It is a natural host to a wide variety of clownfish species.

Diet & Compatibility:

• Diet: This anemone is a Photosynthetic Carnivore. It requires intense illumination to support the zooxanthellae algae in its tissues, but it also benefits greatly from supplemental feeding.
• Feeding: Target-feed meaty foods once or twice a week. Suitable items include small chunks of shrimp, clam, or fish flesh. A healthy anemone will have long, turgid tentacles and a sticky oral disc, quickly accepting the food.
• Lighting & Flow: Requires High to Very High Intensity Lighting (PAR 400+) and Strong, Turbulent Water Flow. It must be placed high on the rockwork in an area that mimics strong wave action. If the conditions are not perfect, it will move, posing a risk to itself and tankmates.
• Placement: Requires a highly established and stable aquarium (12+ months old) of at least 100 gallons to accommodate its size and bioload. It should be placed on a high, open rock surface, allowing its base to secure into a crevice or hole. All powerheads and overflows must be covered to prevent fatal injury.
• Reef Compatibility: With Extreme Caution. The Ritteri Anemone has a powerful sting and is highly mobile if unhappy. It will quickly sting and kill most corals and sessile invertebrates it contacts. It should only be housed in a large tank specifically designed to prevent its movement from harming other life.

Quick Facts

• Current Scientific Name: Heteractis magnifica
• Old Scientific Name: Radianthus ritteri
• Primary Common Name: Ritteri Anemone
• Other Common Names: Magnificent Sea Anemone, Great Anemone
• Origin: Indo-Pacific (Shallow Reef Tops)
• Max Size (Captive): 1.5–2 feet (45–60 cm)
• Temperament: Aggressive (Stinging and Highly Motile)
• Diet: Photosynthetic Carnivore (High Light & Meaty Foods)
• Care Level: Expert Only (Very Difficult)
• Minimum Tank Size: 100–125+ Gallons
• Reef Compatibility: With Extreme Caution (High threat to corals/fish)