QUICK STATS

Care Level: Easy to Moderate
Diet: Carnivore / Planktivore
Temperament: Peaceful to Mildly Territorial
Reef-Safe: Yes
Venomous/Toxic: No
Approximate Purchase Size: 2-4"
Approximate Max Size: Around 4-5"
Recommended Tank Size: 55-90 Gallons or Larger

YELLOW-FLANKED FAIRY WRASSE

The Yellow-Flanked Fairy Wrasse (Cirrhilabrus cyanopleura complex), also commonly sold as the Blue-Sided Fairy Wrasse, is a colorful reef-safe wrasse known for its active swimming behavior, bright male coloration, and peaceful community-tank personality. Males may show red, pink, blue, purple, yellow, orange, or green tones depending on mood, maturity, collection location, and lighting. Basically, the fish is a living paint sample with fins.

Yellow-Flanked Fairy Wrasses are active planktivores that spend much of the day swimming in the water column and picking food from the current. They are excellent additions to reef aquariums because they bring movement, color, and activity without bothering corals. They do need swimming space, stable water quality, and a secure lid, because fairy wrasses are beautiful little escape artists with no respect for gravity.

This species is considered reef-safe and should not bother soft corals, LPS, SPS, zoanthids, mushrooms, clams, or anemones. They may occasionally eat tiny crustaceans or small ornamental microfauna, but they are not typically a threat to cleaner shrimp, snails, hermit crabs, or common reef invertebrates. Reef-safe, yes. Microfauna-safe, less guaranteed, because apparently snacks are snacks.

Note: Image is a representation of what to expect. The fish you receive may vary slightly in size, color, sex, maturity, markings, and overall appearance.

AQUARIUM REQUIREMENTS

AQUARIUM SIZE

A minimum tank size of 55 gallons or larger is recommended for a Yellow-Flanked Fairy Wrasse, with 90 gallons or larger preferred for active community reef aquariums, male specimens, or mixed wrasse systems.

This species is an active swimmer and needs open water space along with rockwork for security. Tank length matters more than height. A long aquarium with open swimming lanes is much better than a tall narrow tank pretending vertical water counts as a racetrack. Fish remain tragically uninterested in our spreadsheet logic.

HABITAT RECOMMENDATIONS

Yellow-Flanked Fairy Wrasses do best in established aquariums with open swimming room, live rock, caves, shaded areas, and peaceful tank mates.

Aquascaping: Provide open swimming room in the front and upper areas of the aquarium along with rockwork, caves, and crevices for shelter.

Substrate: Sand, fine aragonite, crushed coral, or bare-bottom systems can all work. Fairy wrasses do not bury in the sand to sleep like many Halichoeres wrasses.

Rockwork: Live rock is strongly recommended. It provides shelter, territory, biological filtration, and places for the wrasse to retreat when startled or resting.

Tank Maturity: A mature aquarium is preferred. Established systems provide better stability and natural microfauna, though this species usually adapts well to frozen and prepared foods.

Lighting: Moderate reef lighting is fine, but shaded rockwork and caves should be available. Newly introduced wrasses may hide at first and appreciate lower-stress areas.

Tank Cover: A tight-fitting lid is mandatory. Fairy wrasses are notorious jumpers and can escape through small gaps. The floor remains undefeated, smug, and weirdly committed to collecting expensive fish.

WATER PARAMETERS

Yellow-Flanked Fairy Wrasses are generally hardy once established, but they still need clean, stable marine conditions. “Hardy wrasse” does not mean “compatible with mystery water,” because chemistry remains the hobby’s least forgiving little bureaucrat.

Temperature: 72-78°F
pH Level: 8.1-8.4
Salinity: 1.020-1.026 specific gravity
Ammonia, Nitrite, and Nitrate: Ammonia and nitrite should remain undetectable. Nitrate should be kept as low as reasonably possible, ideally below 20 ppm.
Water Flow: Moderate water movement is ideal. Provide enough flow to keep the aquarium oxygenated, move food through the water column, and support active swimming, while still allowing calmer areas near rockwork for resting.

DIET

Yellow-Flanked Fairy Wrasses are carnivorous planktivores that naturally feed on small crustaceans, zooplankton, copepods, and other tiny meaty foods in the water column. In aquariums, they usually adapt well to frozen and prepared foods.

PRIMARY DIET

Frozen Food: Offer mysis shrimp, enriched brine shrimp, cyclops, calanus, marine blends, finely chopped seafood, and other small meaty frozen foods. We at Summit City Coral prefer frozen foods such as LRS Reef Frenzy and PE Mysis.

Prepared Foods: High-quality marine pellets, flakes, carnivore pellets, and small omnivore foods can help provide balanced nutrition. Smaller food sizes are best.

Live Foods: Copepods, amphipods, live brine shrimp, blackworms, and other small live foods can help encourage feeding, especially in newly introduced or hesitant individuals.

Small Meaty Foods: Finely chopped clam, shrimp, krill, and other marine-based foods can be offered in rotation. Avoid oversized foods unless you enjoy watching a wrasse inspect dinner like it has been handed a furniture assembly manual.

FEEDING FREQUENCY

Feed small amounts 1-2 times per day, or 2-3 times per day for new, smaller, or especially active individuals. Fairy wrasses are active fish with fast metabolisms, so consistent feeding helps maintain weight, color, and energy.

COMPATIBILITY

Yellow-Flanked Fairy Wrasses are generally peaceful and work well in reef aquariums with other peaceful to semi-peaceful fish. They are usually safe with coral and most invertebrates, but should be protected from aggressive or overly dominant tank mates.

COMMON TANK MATES

Fish: Clownfish, cardinalfish, gobies, blennies, firefish, chromis, peaceful wrasses, dwarf angelfish, tangs in larger aquariums, rabbitfish, foxfaces, and other peaceful to semi-peaceful community fish.

Avoid: Aggressive dottybacks, aggressive damsels, large predatory fish, large triggers, groupers, lionfish, aggressive wrasses, and any fish likely to bully or eat them.

Other Wrasses: Can often be kept with other peaceful fairy wrasses or flasher wrasses in larger aquariums, especially when introduced carefully. Avoid mixing with overly aggressive wrasses or similar males in undersized tanks.

Same Species: One male may be kept with females in larger aquariums if introduced carefully. Multiple males may fight, especially in smaller systems.

Invertebrates: Usually safe with cleaner shrimp, hermit crabs, snails, urchins, and most common reef invertebrates. Very tiny crustaceans, pods, and microfauna may be eaten.

Coral: Yellow-Flanked Fairy Wrasses are considered reef-safe and should not bother soft corals, LPS, SPS, zoanthids, mushrooms, clams, or anemones.

BEHAVIORAL NOTES

Temperament: Peaceful to mildly territorial. Usually calm with most community fish but may display toward other wrasses.

Activity Level: Very active swimmer that spends much of the day moving through open water and around rockwork.

Planktivore Behavior: Feeds from the water column and often picks small foods from the current.

Reef Compatibility: Excellent for reef tanks. They generally ignore coral and most invertebrates.

Sleeping Behavior: Fairy wrasses typically sleep in rockwork or mucus cocoons rather than burying in sand.

Male Coloration: Males are usually larger and more colorful than females. Color can intensify during display, courtship, stress, or social interactions.

Female / Juvenile Coloration: Females and juveniles may show softer pink, orange, red, or yellow coloration and may look less intense than terminal males.

Wrasse Social Behavior: May flash, display, or posture toward other wrasses. This is normal unless it turns into constant chasing or stress.

Jumping: A tight-fitting lid is mandatory. Fairy wrasses can and will find small openings with the determination of a tiny aquatic fugitive.

Acclimation Sensitivity: Like many wrasses, new arrivals may hide after introduction. Give them time, low stress, and peaceful tank mates while they settle in.

Tank Size Reality: Smaller specimens may appear manageable in smaller tanks, but active fairy wrasses benefit from more swimming room than their body size suggests. Tiny fish, annoying as this is, still have behavior.

ACCLIMATION PROCESS

This acclimation method helps reduce stress by gradually introducing the fish to your aquarium’s temperature and water chemistry.

1. TURN OFF THE LIGHTS & ATO

Turn off aquarium lights to reduce stress. If you have an Auto Top Off system, switch it off before starting acclimation.

2. FLOAT THE BAG

Float the sealed bag in the aquarium for 15-20 minutes to allow the temperature in the bag to equalize with the tank.

3. OPEN BAG, ADD FISH TO CONTAINER

Carefully open the bag and transfer the fish and shipping water into a clean bucket or container.

4. ACCLIMATE USING TANK WATER

Add 1/4 cup of tank water to the container every 5 minutes for 40 minutes.

5. TRANSFER FISH TO AQUARIUM

Once acclimation is complete, gently transfer the fish into the aquarium using a net or specimen container. Wrasses can jump suddenly when startled, so keep the transfer controlled and cover the container if needed. Discard the shipping water. Do not pour shipping water into your aquarium.

6. REFILL THE AQUARIUM WITH SALTWATER

You may need to replace the saltwater removed during acclimation with fresh mixed saltwater.