Yellow Flanked Fairy Wrasse

Yellow Flanked Fairy Wrasse: The Flashing Reef Jewel

The Yellow-Flanked Fairy Wrasse (Cirrhilabrus ryukyuensis) is a stunningly colorful and highly sought-after member of the Cirrhilabrus genus. This species is often grouped with, and sometimes confused with, the Blueside Fairy Wrasse (Cirrhilabrus cyanopleura), but mature males of this species are uniquely defined by a conspicuous triangular yellow patch on their flanks, located just behind the pectoral fins.

Native to the Western Pacific, primarily around the Ryukyu Islands of Japan, Indonesia, and the Philippines, this wrasse is a mid-water swimmer that brings energy and vibrant color to the aquarium. Males display a gorgeous palette, often featuring a dark navy blue to purple head, a pinkish-mauve body, and the signature yellow flank spot. These colors intensify dramatically during courtship rituals, where the male "flashes" its extended fins and body coloration.

Reaching a modest size of up to 5-6 inches (13-15 cm) in a mature male, the Yellow-Flanked Fairy Wrasse requires a minimum aquarium size of 55 gallons to accommodate its active nature. Like all Fairy Wrasses, it is an expert jumper, so a tight-fitting lid or screen top is mandatory to prevent loss.

Diet & Compatibility:

• Diet: This fish is a dedicated Carnivore and a specialized Zooplankton Feeder. In captivity, it requires frequent, small feedings (2-3 times per day) to support its high metabolism and active swimming. The diet should consist of high-quality, meaty frozen foods like vitamin-enriched mysis shrimp, copepods, brine shrimp, and fine marine pellets or flakes. A varied diet is essential for maintaining their brilliant colors and overall health.
• Sleeping Habit: Unlike the Halichoeres wrasses, Cirrhilabrus wrasses do not bury in the sand. They form a protective mucus cocoon among the rockwork or in a crevice at night to sleep.
• Reef Compatibility: It is Completely Reef Safe. This wrasse will not harm corals, clams, or sessile invertebrates. Due to its diet of zooplankton, it generally ignores the clean-up crew, though very small ornamental shrimp should be monitored.
• Temperament: It is generally Peaceful and Active. It thrives in a peaceful community environment and is best kept as a single male or in a harem (one male with several smaller females) if the tank is large enough (90+ gallons) and all are introduced simultaneously. Males may display aggression toward other Fairy Wrasses, particularly those of similar size or color. It should not be housed with overly aggressive or predatory tankmates.

Quick Facts

• Scientific Name: Cirrhilabrus ryukyuensis
• Primary Common Name: Yellow-Flanked Fairy Wrasse
• Other Common Names: Ryukyu Fairywrasse, Bluehead Fairy Wrasse, Purplehead Parrotfish
• Origin: Western Pacific (Ryukyu Islands, Japan, Indonesia, Philippines)
• Max Size: 5-6 inches (13-15 cm)
• Temperament: Peaceful / Active (High jumper)
• Diet: Carnivore (Zooplankton Feeder)
• Minimum Tank Size: 55+ Gallons
• Reef Compatibility: Yes (Completely safe with corals and most inverts)