Yellow-Flanked Fairy Wrasse (Cirrhilabrus ryukyuensis)
• Small fish safe: ✅ Yes (peaceful and non-aggressive)
• Small invertebrate safe: ✅ Yes (reef-safe; does not harm invertebrates)
• Coral safe: ✅ Yes (does not harm corals)
• Minimum tank size: 340 litres (90 gallons)
• Adult size: Up to 15 cm (6 inches)
• Diet: Carnivorous, feeding on zooplankton and small meaty foods
• Be aware of: Prone to jumping (requires a tight-fitting lid); males exhibit vibrant coloration; best kept singly or in harems with one male and multiple females
Appearance and Coloration
The Yellow-Flanked Fairy Wrasse is a visually striking species exhibiting notable sexual dimorphism:
• Males: Display a multicolored body with a greenish-blue head and a large yellow triangular patch on their sides. Depending on the geographic location, this yellow patch may appear pinkish. During courtship, males intensify their colors to attract females.
• Females and Juveniles: Generally exhibit more subdued coloration, often with shades of reddish-purple above and white below, with black spots on the upper caudal peduncle.
Natural Habitat and Behaviour
Cirrhilabrus ryukyuensis is native to the Western Pacific Ocean, ranging from Indonesia, Malaysia, and the Philippines north to Japan. They inhabit coral reefs, typically at depths ranging from 2 to 30 meters (6 to 98 feet).
• Social Structure: Often found in small groups, with a dominant male overseeing several females and juveniles.
• Activity: Diurnal and active swimmers, spending most of their time mid-water, foraging for planktonic prey.
• Behavior: Peaceful and non-aggressive, making them an excellent addition to community aquariums.
Tank Requirements and Water Parameters
• Minimum Tank Size: 340 litres (90 gallons)
• Water Parameters:
• Temperature: 22°C – 26°C (72°F – 78°F)
• pH: 8.1 – 8.4
• Specific Gravity: 1.020 – 1.025
• Aquascaping:
• Provide ample live rock formations to create hiding spots and replicate their natural reef environment.
• Ensure open swimming spaces to accommodate their active nature.
• Lighting: Moderate to high, mimicking natural reef conditions.
• Water Movement: Moderate to strong, reflecting their natural habitat.
Important Note: A secure, tight-fitting lid is essential, as Cirrhilabrus ryukyuensis are known jumpers, especially when startled.
Diet and Feeding
In their natural environment, Yellow-Flanked Fairy Wrasses primarily feed on zooplankton. In captivity, they adapt well to a variety of meaty foods.
• Captive Diet:
• Offer vitamin-enriched frozen mysis shrimp and brine shrimp.
• Provide high-quality marine flake and pellet foods.
• Supplement with live foods such as copepods and amphipods to encourage natural foraging behaviors.
Feeding Frequency: Feed small amounts 2-3 times daily to maintain health and vibrant coloration.
Compatibility and Social Structure
• Temperament:
• Generally peaceful and suitable for community aquariums.
• Males may display increased coloration and fin displays during courtship.
• Tank Mates:
• Compatible with other non-aggressive species such as gobies, blennies, and dwarf angelfish.
• Avoid housing with aggressive or significantly larger species that may intimidate or outcompete them.
• Social Structure:
• Best kept singly or in harems with one male and multiple females.
• Introducing multiple males in the same tank can lead to aggression unless the aquarium is sufficiently large.
Important Considerations
• Jumping Behavior: Ensure the aquarium has a secure lid, as these wrasses are prone to leaping out of tanks.
• Acclimation: Introduce them to well-established aquariums with stable water parameters to reduce stress.
• Color Variability: Depending on their geographic origin, the yellow flank may appear pinkish in some individuals.
Summary
The Yellow-Flanked Fairy Wrasse (Cirrhilabrus ryukyuensis) is a vibrant and active addition to marine aquariums. Their peaceful nature, striking coloration, and dynamic swimming behavior make them a favorite among reef keepers. Providing appropriate tank conditions, a suitable diet, and a compatible social environment ensures that this beautiful species will thrive in captivity.