Filamented Fairy Wrasse (Cirrhilabrus filamentosus)
The Filamented Fairy Wrasse, also known as the Whip-fin Fairy Wrasse, is a jewel of the Java Sea and surrounding Indonesian waters. It is best known for the spectacular, long filament that extends from the male's dorsal fin, trailing behind it like a whip as it swims. This species is a favorite for reef hobbyists because it remains relatively small, is exceptionally peaceful, and offers some of the most dramatic "flashing" behavior in the Cirrhilabrus genus.
Key Information
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Common Names: Filamented Fairy Wrasse, Whip-fin Fairy Wrasse
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Scientific Name: Cirrhilabrus filamentosus
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Origin: Western Central Pacific (Indonesia, Java Sea, and Timor Sea)
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Max Size: 8–10 cm (approx. 3.5–4 inches)
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Lifespan: 5–8 years
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Temperament: Peaceful; can be shy with boisterous tank mates
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Diet: Carnivore – Planktivore
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Care Level: Easy to Moderate
Appearance & Identification
The Filamented Fairy Wrasse has a distinct "two-tone" profile:
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The Whip-fin: The hallmark of the terminal male is a single, long filament extending from the middle of the dorsal fin. In prime specimens, this filament can reach back toward the tail.
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Coloration: Males typically feature a vibrant red-to-maroon upper body and a starkly contrasting white-to-creamy yellow belly.
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The "Flash": During courtship or when asserting dominance, the male's colors shift rapidly. The white belly can turn a brilliant, shimmering blue or violet, and the red on the back intensifies.
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The Tail: They possess a "rhomboid" or diamond-shaped tail, often edged in iridescent blue.
Behaviour & Tank Compatibility
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Peaceful Citizen: This is one of the less aggressive fairy wrasses. It rarely bothers other fish and is a perfect candidate for a quiet, sophisticated reef tank.
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Reef Safe: 100% Reef Safe. They are completely safe with all corals, clams, and even the smallest ornamental invertebrates.
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Social Structure: They thrive when kept in a harem (one male with 2–3 females). If kept as a single male, he may lose some of his color intensity over time; the presence of females encourages frequent "flashing."
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Tank Mates: Best kept with other peaceful species like Anthias, Firefish, Flasher Wrasses, and Blennies. Avoid aggressive "bully" wrasses like the Six-Line Wrasse, which may harass the Filamented Wrasse into hiding.
Ideal Tank Setup
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Tank Size: A minimum of 115L (30 Gallons) for a single specimen, though 200L (55 Gallons) is preferred for a harem.
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Lid is Mandatory: Like all fairy wrasses, they are prolific jumpers. They are streamlined and fast; they can easily find even small openings in a canopy.
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Rockwork: Provide plenty of live rock with crevices and caves. They sleep in the rockwork and will use it as a retreat if they feel threatened.
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Lighting: They look best under actinic or high-spectrum reef lighting, which makes their iridescent blue highlights and white underbellies "pop."
Dietary Needs
They have high metabolisms and are active open-water swimmers:
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Feeding Frequency: Feed 2–3 times daily.
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Preferred Foods: Small meaty items like frozen mysis, enriched brine shrimp, and copepods.
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Dry Foods: They usually transition well to high-quality marine pellets and flakes once they feel secure in the tank.
Why Choose the Filamented Fairy Wrasse?
The Filamented Fairy Wrasse is for the aquarist who wants elegance and motion. Its unique "whip-fin" silhouette provides a different look than the standard rounded fins of other wrasses. Because it is native to the Indo-Pacific regions like the Java Sea, it is often more readily available in the local trade and remains one of the most rewarding "functional ornaments" for a peaceful coral reef display.
