Half-banded Flasher Wrasse
Paracheilinus hemitaeniatus
The Half-banded Flasher Wrasse is a rare reef fish renowned for intense iridescent courtship displays. This peaceful, shoaling species requires a 120L tank, secure cover, and frequent feedings of meaty micro-foods.
Water Temperature
22 - 26 °C
pH Value
8.1 - 8.4
Water type
Marine
Tank level
Surface and middle
Adult size
8 cm
Minimum tank volume
>= 120 L
Minimum group
>= 1
KH
8 - 12 dKH
Species description
Geographical Origin and Habitat: This species is native to the Western Pacific, primarily recorded around southern Japan, Taiwan, and the Philippines. It inhabits deep seaward reef slopes, rubble zones, and channels exposed to strong currents, typically found at depths between 20 and 60 meters where it hovers over the substrate.
Taxonomy and Morphology: Belonging to the family Labridae and the genus Paracheilinus. It features a slender, streamlined body with large eyes. Males develop elongated filamentous rays on the dorsal fin as they mature. The maximum adult size is approximately 8 to 9 cm.
Social Behavior: Peaceful and shoaling. It naturally forms small harems consisting of one dominant male and several females. The males are famous for their 'flashing' display, where they rapidly intensify their coloration and flare their fins to court females or deter rival males.
Coloration and Sexual Dimorphism: Exhibits pronounced sexual dimorphism. Females are reddish-orange with faint horizontal lines. Males are intensely colored, showing reddish-orange bases, bright neon blue lines, and a distinct dark half-band on the lower side of the body, which turns iridescent during displays.
Care, breeding and tankmates
Aquarium Setup: Requires an established reef aquarium of at least 120 liters (30 gallons). Provide plenty of open space for active swimming along with rockwork containing caves for shelter. A secure, tight-fitting lid or mesh cover is mandatory, as this species is an notorious jumper when startled.
Diet and Feeding: Planktonic feeder. In captivity, it must be fed 2 to 3 times daily with small, meaty frozen foods such as mysis shrimp, brine shrimp, copepods, and fish eggs. It will also accept high-quality marine flakes and micro-pellets. Frequent feeding helps maintain their high metabolism.
Water Quality: Demands stable marine parameters: temperature 23-26°C (73-79°F), pH 8.1-8.4, specific gravity 1.020-1.025, and KH 8-12. Ensure excellent filtration and water movement to provide high dissolved oxygen levels, which mimics their natural current-swept habitat.
Compatibility and Cohabitation: Reef-safe and peaceful. Excellent addition to community reef aquariums. Can be kept in small groups (one male with multiple females). Avoid housing with aggressive, territorial species like large dottybacks, hawkfish, or combative damselfishes that may stress it.
Aquarium Breeding: Spawning in captivity is exceptionally rare and difficult to manage. They are open-water pelagic spawners, releasing gametes into the water column during sunset. Rearing the resulting planktonic larvae requires specialized live food and culture techniques.
Risks and Diseases: The primary risk is jumping from an uncovered tank. It is susceptible to skin parasites such as marine ich (Cryptocaryon) if stressed by aggressive tankmates or poor water quality. Ensure a calm acclimation period and quarantine before introducing to the main tank.
Geographic Origin and Distribution
This species is native to the Western Pacific, primarily recorded around southern Japan, Taiwan, and the Philippines. It inhabits deep seaward reef slopes, rubble zones, and channels exposed to strong currents, typically found at depths between 20 and 60 meters where it hovers over the substrate.
Origin
Tropical oceans and reefsAfrica and MadagascarSouth and Southeast AsiaEast Asia
Fish profile
- Temperament
- Peaceful
- The Paracheilinus hemitaeniatus has a timid and entirely peaceful temperament. They are easily bullied by more assertive fish, which can cause them to remain hidden and refuse food. When housed with appropriate peaceful companions, they become active and highly entertaining.
- Diet
- Carnivore
- In nature, Paracheilinus hemitaeniatus feed predominantly on zooplankton drifting in the water column above the reef. Captive specimens require a varied carnivore diet consisting of enriched brine shrimp, mysis shrimp, and finely chopped seafood. High-quality marine flake and pellet foods are usually accepted readily.
- Life expectancy
- 3-5 years
- In captivity, the Half-banded Flasher Wrasse typically lives for 3 to 5 years under optimal husbandry. Ensuring a stable marine environment, keeping stress to a minimum, and offering a high-quality carnivore diet are essential for their health. A covered tank is highly recommended, as they are capable jumpers and can easily leap out of open aquariums.
- Adult size
- 8 cm
- The catalog's scalar value is 8 cm. The FishBase SPECIES table (v25.04 snapshot) source reports a maximum adult measurement of 5.6 cm for this species, recorded as standard length (SL). The taxonomic record consulted is Paracheilinus hemitaeniatus (v25.04); male or unsexed record. These figures are not interchangeable: the first is the profile's editorial reference, whereas the second is a published maximum under a specific measurement convention; differences among sources can reflect sex, population, life stage and measuring method.
- Sex ratio
- Flexible
- Keeping a single male with multiple females allows the male to display his spectacular mating colors naturally. Multiple males of the same or similar species should not be kept together as they will fight relentlessly. Introduce all females either simultaneously or prior to the dominant male.
- Feeding frequency
- Twice daily
- Due to their rapid digestion and constant activity, these wrasses should be fed small quantities at least two to three times daily. Providing multiple small meals ensures they maintain a healthy body weight and strong immune system. Infrequent feeding can lead to gradual starvation and lethargy.
- Bioload
- Flasher wrasses such as Paracheilinus hemitaeniatus possess a relatively low to moderate bioload footprint in the marine aquarium. They are small and metabolically active, generating waste primarily proportional to their required frequent feedings. Proper mechanical filtration and protein skimming easily manage their output.
- Flow
- Strong
- They appreciate moderate to high water flow within the aquarium environment. Dynamic flow patterns simulate the turbulent reef drop-offs they originate from and encourage natural swimming behaviors. A strong current also aids in keeping their zooplankton-like foods suspended longer.
- Jump risk
- Yes
- The jumping capability of Paracheilinus hemitaeniatus is legendary among aquarists; they will readily leap from open-top tanks. It is absolutely essential to secure the aquarium with a tightly fitting mesh lid or glass canopy. Ensuring there are no gaps near overflow boxes or equipment cords will prevent tragic losses.
- Reproduction
- Oviparous
- Flasher wrasses are protogynous hermaphrodites, changing sex from female to male based on social hierarchy. Successful captive breeding is undocumented due to their pelagic spawning habits and microscopic larvae. Males are famous for their rapid, dramatic color flashes during evening courtship rituals.
- Compatibility & tankmates
- Community
- They are incredibly peaceful and make stellar additions to the community reef tank. They pose zero threat to corals or ornamental invertebrates, making them completely reef safe. However, they can easily be intimidated by larger, more aggressive tank mates like tangs or large angels.
- Tank level
- Top/Middle
- They primarily occupy the middle and upper levels of the water column, darting about in search of food particles. Despite their open-water swimming, they remain close to the reef structure for safety. When frightened or resting at night, they dive directly into small rockwork crevices or mucus cocoons.
Scientific Parameters & Models
FishBase
Window to the official scientific data of the species
Data synced on: 06/15/2026
- Trophic level
- 3.4 ± 0.4 se
- Resilience
- High (less than 15 months)
- Phylogenetic uniqueness (PD50)
- 0.5
- Bayesian Length-Weight
- a = 0.01072, b = 3.03
- VulnerabilityLow vulnerability (10 / 100)
Image gallery
Licensed images linked to the species or, when marked, to the closest representative taxon.
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