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McCosker's Flasher Wrasse

McCosker's Flasher Wrasse

The McCosker's Flasher Wrasse is a small but eye-catching wrasse, its orange body streaked with neon blue lines. Its name comes from the "flashing" display males perform during courtship, spreading their fins wide to show off vivid color — a memorable sight when you happen to catch it in the tank. Generally peaceful and reef-safe, it pairs well with corals and other small, non-aggressive fish. At just 6-8cm as an adult, it stays compact enough to suit tanks without demanding excessive space. That said, it tends to settle in best when kept alone or with careful tankmate selection, so compatibility is worth thinking through. Considered suitable for intermediate keepers, it fits those who already have some experience managing stable water quality and reef conditions.

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McCosker's Flasher Wrasse key facts

Care level
Intermediate
Lifespan
4-6 years
Size
6-8cm
Temperature
24〜27℃
Diet
Zooplankton, frozen food, pellets
Tank
60cm+. Lid absolutely essential — extreme jumper
Water Temperature & Quality
Keep the water at 24-27°C with good water quality. An active swimmer, so allow plenty of open swimming space.
Diet & Feeding
A zooplankton feeder that readily takes frozen foods and pellets. Because it swims constantly, feed in several small portions.
Keeping Style
Ideal as harem: 1 male + multiple females
Tank Mates & Compatibility
Peaceful and reef-safe. An excellent community fish that does no harm to corals or invertebrates and mixes with many species.
Lighting
Colors better in moderate light. Best flashing near lights-out
TraitsIntermediateSmallBeautifulReef safe

About McCosker's Flasher Wrasse

A striking small wrasse in orange with neon-blue lines. Reef-safe, 4-6 year lifespan, grows to 6-8cm. Best suited to intermediate keepers.

7 things to know before welcoming a McCosker's Flasher Wrasse

  1. 1Watch for the flashing display

    Males perform a display called "flashing," spreading their fins wide to show off vivid color during courtship — the behavior the species is named for, and one of the joys of keeping it. When and how often you see it varies by individual and setup.

  2. 2Reef-safe and sociable

    This species is reef-safe, rarely bothering corals or invertebrates, which makes it a good fit for reef tanks. It also gets along well with other small, peaceful fish.

  3. 3A compact adult size

    Adults reach only about 6-8cm, staying compact throughout life. This modest size makes them easier to accommodate without needing excessive tank space.

  4. 4Often calmer kept singly

    They can show territorial behavior toward conspecifics or similarly colored fish, and tend to settle in more calmly when kept alone. If housing with tankmates, think carefully about the combination.

  5. 5Guard against jumping

    Like many wrasses, this species may jump out of the tank when startled. A secure lid or gap coverage helps keep them safe.

  6. 6They may bury in the sand

    They sometimes bury themselves in the substrate at night or when feeling threatened. Providing a reasonably deep sand bed can help them feel more secure.

  7. 7Suited to intermediate keepers

    This species is rated as suitable for intermediate keepers, so some experience with water quality management and tank maintenance is recommended. Expected lifespan is around 4-6 years.

Frequently asked questions about McCosker's Flasher Wrasse

Q.Can beginners keep this fish?
A.This species is rated for intermediate keepers. It's best to have some experience with water quality management and reef tank maintenance before bringing one home.
Q.Can it be kept with other fish?
A.It's generally reef-safe and peaceful, but may show territorial behavior toward conspecifics or similarly colored fish. Choose tankmates carefully.
Q.How big does it grow?
A.It's a small wrasse that reaches about 6-8cm as an adult, and doesn't require an especially large tank.
Q.What is the "flashing" behavior?
A.It's a courtship display where males spread their fins wide to show off vivid color — the behavior this species is named after.
Q.What is its lifespan?
A.With appropriate care, the expected lifespan is around 4-6 years.

Useful tools for McCosker's Flasher Wrasse care

💧Aquarium Volume CalculatorCalculate water volume, weight, and heater wattage from tank dimensions🧪Water Quality CheckerFind compatible fish, shrimp, plants & corals based on pH, temperature & hardness🍽️Feeding GuideCheck feeding frequency, portion sizes & supplements by species and growth stage🤝Compatibility CheckerCheck compatibility between two species on a 5-level scale📊Fish Compatibility MatrixCheck fish compatibility at a glance with our matrix chart🔄Nitrogen Cycle GuideAuto-calculate bacteria colonization timeline for new tank cycling🗓️Seasonal Care CalendarMonthly care events and seasonal management tips at a glance🚿Water Change CalculatorAuto-calculate optimal water change frequency and volume by tank size and fish count🐠Stocking CalculatorCalculate max fish capacity for your tank size with overstocking alerts🏞️Tank Layout PlannerGet substrate, plant & hardscape suggestions based on tank size and style🧮Care Cost SimulatorEstimate initial, monthly & annual costs by category, care level and quantity⚖️Species Comparison ToolCompare two species side by side: care difficulty, size, lifespan & temperature🎯Pet Match DiagnosticAnswer 7 questions to find your top 3 perfect pets🚚Transport Safety CheckerCheck transport safety score and precautions by category, season, method and distance⏱️Quarantine & Acclimation TimerManage quarantine periods and acclimation steps with countdown timers. Includes recommended durations by species

Learn more about McCosker's Flasher Wrasse in the encyclopedia

View McCosker's Flasher Wrasse encyclopedia entry →

Care difficulty, lifespan, size and diet — all basics covered.

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