The Bluesided Fairy Wrasse, Cirrhilabrus cyanopleura, is one of the more variable members of its genus, with coloration shifting noticeably by collection locality. That variation has produced several trade names, including Bluehead Fairy Wrasse and Yellowflanked Fairy Wrasse, and it can make identification of individual specimens genuinely tricky. Terminal males show brilliant blue flanks that flare in intensity during courtship displays, while females and juveniles remain more subdued in orange and pink tones. Adults reach roughly 5.9 inches. The species ranges widely through the Indo-Pacific, from the Eastern Indian Ocean at Rowley Shoals, the Similan Islands, the Andaman Sea, and Christmas Island, east to the Ryukyu Islands, Taiwan, the Philippines, Papua New Guinea, Palau, Indonesia, and the Great Barrier Reef, where it occupies coral reefs and adjacent rubble zones. Like many fairy wrasses, it is capable of changing sex.

Plan on a 75-gallon aquarium as the practical minimum for a single specimen, with 100 to 200 gallons or more preferred when housing a group or combining several wrasse species. This is a strong, tireless swimmer, so open water matters as much as total volume. Build the aquascape around abundant live rock with caves and crevices to explore, and provide a moderate to deep sand bed, since the fish burrows into the substrate at night and when startled. A tight-fitting lid is not optional. This wrasse jumps, and its instinctive reaction to being chased is to bolt straight upward, which puts it at risk of landing on the floor or dropping into an overflow. A mature, well-established system suits it best, and it is most successful when introduced as a mated pair or as one male with several females, either added simultaneously or with the females settled in first.