Pseudanthias randalli (Randall’s Anthias)
• Small fish safe: ✅ Yes
• Small invert safe: ✅ Yes
• Coral safe: ✅ Yes
• Minimum tank size: 265L+ (70 gallons) for a single specimen; larger for groups
• Adult size: ~7.6 cm (3 inches)
• Diet: Carnivorous (zooplankton, frozen mysis/brine shrimp, enriched flake foods)
• Be aware of: Requires frequent feedings due to high metabolism. Best kept in harems (one male with multiple females). May be shy initially; provide ample hiding spots. Avoid housing with aggressive tankmates.
Randall’s Anthias (Pseudanthias randalli) – A Vibrant and Peaceful Reef Addition
The Randall’s Anthias is a stunning and relatively small anthias species known for its vibrant coloration and peaceful demeanor. Originating from the Western Pacific Ocean, this species is a popular choice for reef aquarists seeking a colorful and active addition to their tanks.
Appearance and Coloration
Randall’s Anthias exhibit distinct sexual dimorphism, with males and females displaying different color patterns:
• Males: Feature a vibrant striped pattern in red and magenta, with hues of purple and yellow. The dorsal fin is often elongated, and the caudal fin may display filamentous extensions.
• Females: Display similar colors but are less vibrant, with a pale underbelly and a yellow snout. Their fins are more rounded compared to males.
This striking coloration makes Randall’s Anthias a visually appealing species in marine aquariums.
Natural Habitat and Behavior
In the wild, Randall’s Anthias are found in the Western Pacific Ocean, inhabiting:
• Deep reef slopes: Typically at depths ranging from 15 to 70 meters (50 to 230 feet), often near caves and crevices that provide quick hiding places.
• Social Structure: They form harems consisting of one dominant male and multiple females. If the dominant male perishes, the largest female will often morph to take its place.
In captivity, they thrive in well-structured aquariums with ample hiding spots and open swimming areas.
Tank Requirements and Water Parameters
To ensure the well-being of Randall’s Anthias in captivity:
• Minimum Tank Size: A 70-gallon (265 liters) tank is suitable for a single specimen. For groups, a 125-gallon (475 liters) or larger aquarium is recommended.
• Water Parameters:
• Temperature: 72°F – 78°F (22°C – 25.5°C)
• pH: 8.1 – 8.4
• Specific Gravity: 1.020 – 1.025
• Aquascaping: Provide ample live rock formations to create hiding spots and territories, while ensuring open swimming spaces.
• Lighting: Standard reef aquarium lighting is sufficient.
• Water Movement: Moderate to strong, simulating their natural reef environment.
Maintaining stable water conditions is crucial for their health.
Diet and Feeding
Randall’s Anthias have a high metabolism and require frequent feedings:
• Diet: Primarily carnivorous, feeding on zooplankton in the wild. In captivity, offer:
• Frozen mysis shrimp
• Enriched frozen brine shrimp
• High-quality flake foods
• Live foods (e.g., copepods, amphipods) can be beneficial, especially during acclimation.
• Feeding Frequency: Due to their constant activity and high metabolisms, they should be fed small amounts several times per day (at least three times daily) to maintain good health.
An attached refugium cultivating copepods and amphipods provides a steady supply of nutritious live food, which can be beneficial for this active planktivore.
Compatibility and Social Structure
Randall’s Anthias are social fish that thrive in groups:
• Social Structure: Best kept in harems consisting of one male and multiple females. Avoid keeping multiple males in the same tank, as it can lead to aggression.
• Temperament: Generally peaceful but may be shy, especially when first introduced. They should not be housed with overly aggressive species.
• Compatible Tank Mates: Suitable companions include other peaceful reef fish, such as gobies, blennies, and small wrasses. Avoid housing with aggressive or overly competitive feeders.
Providing a peaceful environment with compatible tank mates will help reduce stress and encourage natural behaviors.
Important Considerations
• Acclimatization: Randall’s Anthias can be sensitive during transportation and acclimatization into the aquarium.