Blackfin Fairy Wrasse (Cirrhilabrus Melanomarginatus) saltwater aquarium fish portrait

Cirrhilabrus melanomarginatus is a Western Pacific fairy wrasse documented from Malaysia east to the Philippines and Taiwan, extending north to southern Japan. Males display a dark body offset by a white belly, with red dorsal and anal fins finely edged in black, the trait that gives the species its common name. Females are largely purple and carry a distinct black spot on the upper caudal peduncle. Adults reach roughly 5 inches in standard length, placing them among the larger members of the genus.

In the wild this is a reef-associated species that patrols rocky bottoms at depths of about 6 to 40 meters, and successful aquarium housing reflects that preference. Provide a minimum of 50 gallons for an adult, with generous rockwork arranged to create crevices and caves where the fish can retreat during the day and wedge itself in at night. Unlike sand-diving wrasses, this species has no need for a sand bed to bury into and instead relies entirely on hard structure for security.

A tightly fitted lid or complete top coverage is not optional. Fairy wrasses are powerful jumpers and are most likely to launch themselves when startled by sudden movement, netting, or aggression from a tankmate. Open overflow channels and gaps around equipment should be screened as well. Care level is moderate, largely because of that escape risk and the need for frequent, well-managed feedings rather than any particular sensitivity to standard reef conditions.

On the reef, Cirrhilabrus melanomarginatus feeds on zooplankton picked from the water column above rock and rubble. In the aquarium it is a straightforward carnivore that takes finely chopped meaty items readily, including mysis, shrimp, squid, fish flesh, and clam. Quality frozen preparations, live foods, and flake foods aimed at marine carnivores round out the rotation and help maintain color and body condition.

Because this wrasse is built to graze continuously on small prey, two to three modest meals per day suit it far better than a single large offering. Newly introduced individuals often retreat into the rockwork for several days, so monitor the feeding response closely through acclimation and continue to offer small portions until the fish begins competing openly at the surface. Chopping food to an appropriate size makes early acceptance much more likely.

Mysis Shrimp Chopped Shrimp Squid Fish Flesh Clam Frozen Carnivore Preparations Marine Flake Food
This is an active, open-water swimmer that spends most of the day cruising above and around the rockwork, returning to crevices to rest. Temperament is peaceful, and the species is best paired with equally mild tankmates that will not intimidate it or monopolize feedings. Expect a shy first week, with the fish emerging progressively as it learns the layout of the tank and the feeding routine. Fairy wrasses can also be kept socially as a single male with several females, provided the entire group is introduced at the same time so no individual establishes prior claim to the rockwork.

Reef compatibility is excellent. The species is reported as safe with corals and is well suited to mixed reef displays, where its swimming activity and adult coloration show to good effect. One caveat is worth noting: fairy wrasses have been observed picking at very small crustaceans, so valuable ornamental shrimp and delicate micro-crustaceans deserve observation after introduction, even though the fish is generally trustworthy around sessile invertebrates.

FAQ

Frequently Asked Questions

About the Blackfin Fairy Wrasse

  • What minimum aquarium size and enclosure does a Blackfin Fairy Wrasse need?
    Adults should be housed in at least a 50-gallon aquarium furnished with rockwork, crevices, and caves. A tightly fitting lid is essential, since this wrasse jumps when startled.
  • Is the Blackfin Fairy Wrasse safe for a reef aquarium?
    Yes, it is reported as coral-safe and well suited to reef systems. Very small ornamental crustaceans should still be watched, as fairy wrasses may pick at them.
  • What should it be fed, and how often?
    Offer finely chopped meaty foods such as mysis, shrimp, squid, fish flesh, and clam, along with frozen, live, and prepared marine carnivore items. Two to three small meals each day work best.