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Regal Anthias
Pseudanthias regalis
A rare and highly exclusive anthias species endemic to the Marquesas Islands. Extremely delicate and suitable only for advanced aquarists.
Water Temperature
24 - 27 °C
pH Value
8.1 - 8.4
Water type
Marine
Tank level
Bottom and middle
Adult size
9 cm
Minimum tank volume
>= 300 L
Minimum group
>= 4
KH
8 - 12 dKH
Species description
Geographical Origin and Habitat: This species is native to the Southeastern Pacific Ocean, being an exclusive endemic to the Marquesas Islands in French Polynesia. It inhabits steep outer reef slopes and drop-offs at significant depths, typically between 30 and over 60 meters, where light penetration is weak and the water remains cool, clear, and swept by strong currents.
Taxonomy and Morphology: It belongs to the Serranidae family, subfamily Anthiadinae. It features an elongated, laterally compressed body with an elegant lyre-shaped caudal fin equipped with extended filaments. The eyes are large and situated forward, adapted to hunting zooplankton in dim light conditions. Adults reach a maximum size of about 8-9 centimeters.
Social Behavior: It is a peaceful, shy, and highly gregarious fish that forms large, coordinated schools in the wild. They quickly retreat into coral branches when startled. Like most anthias, it exhibits protogynous hermaphroditism, meaning a dominant male maintains a territory and controls an harem of several females.
Coloration and Sexual Dimorphism: The coloration is striking, displaying intense shades of pink, magenta, and violet that merge into golden yellow and orange along the dorsal profile and fins. Sexual dimorphism is highly pronounced: dominant males exhibit far more vibrant colors, elongated dorsal and pelvic fin rays, and longer caudal filaments.
Care, breeding and tankmates
Aquarium Setup: Requires a mature marine aquarium of at least 300 liters, featuring a large open swimming area and plenty of stable live rock arranged to create shaded caves, overhangs, and crevices where the fish can seek shelter. Moderate or dim lighting is preferred to replicate its deep-water habitat, and a secure lid is mandatory.
Diet and Feeding: A strict planktivorous carnivore that needs to be fed 3 to 4 times daily in small amounts. Offer a varied diet of high-quality frozen foods, such as vitamin-enriched copepods, mysis shrimp, brine shrimp, and lobster eggs. It is notoriously difficult to acclimate to dry foods, which may initially be ignored.
Water Quality: Demands pristine and stable water conditions. The temperature should be maintained between 24 and 27 °C, pH between 8.1 and 8.4, and specific gravity stable between 1.020 and 1.025. A powerful protein skimmer and efficient powerheads are recommended to simulate strong, highly oxygenated currents.
Compatibility and Cohabitation: A completely reef-safe species that will not harm corals or sessile invertebrates. It must be housed only with peaceful, non-aggressive tankmates. Avoid active, territorial, or aggressive fish that could easily intimidate this shy species, preventing it from feeding.
Aquarium Breeding: Captive breeding has not been successfully documented in private home aquariums. This is due to their pelagic spawning habits and a complex oceanic larval stage that requires specialized microscopic live feeds not easily cultivated in home setups.
Risks and Diseases: Highly susceptible to stress during transit and acclimation. Under stressful conditions or sudden temperature fluctuations, they are prone to contracting marine ich (Cryptocaryon) or velvet (Oodinium). The primary risk is starvation, making it vital to ensure they are feeding before purchase.
Geographic Origin and Distribution
This species is native to the Southeastern Pacific Ocean, being an exclusive endemic to the Marquesas Islands in French Polynesia. It inhabits steep outer reef slopes and drop-offs at significant depths, typically between 30 and over 60 meters, where light penetration is weak and the water remains cool, clear, and swept by strong currents.
Origin
Tropical oceans and reefs
Fish profile
- Temperament
- Peaceful
- The temperament of Pseudanthias regalis is generally peaceful towards completely unrelated fish, making them wonderful community residents. However, they establish a strict pecking order within their own group, which can involve some chasing and posturing. The dominant male will frequently display to the females to maintain his status and keep the harem in line. While usually harmless, this internal squabbling requires adequate space and hiding spots for subordinate individuals. They should not be housed with overly aggressive predators that might bully or consume them.
- Diet
- Carnivore
- In the wild, Pseudanthias regalis is a dedicated zooplanktivore that constantly picks tiny organisms from the water column. In the home aquarium, they require a varied diet consisting of high-quality frozen or live meaty foods. Suitable options include mysis shrimp, enriched brine shrimp, copepods, and finely chopped seafood. Getting them to accept dry prepared foods like high-quality flakes or small pellets can take time and patience. A diverse nutritional profile is crucial for maintaining their vibrant coloration and immune health.
- Life expectancy
- 2-5 years
- Regal Anthias typically have a lifespan of 2 to 5 years when kept in captivity under optimal environmental conditions. To reach their maximum life expectancy, they require extremely stable water parameters, low stress, and a constant supply of high-quality food. In poorly managed systems, their lifespan is drastically reduced due to their sensitivity to environmental fluctuations.
- Adult size
- 9 cm
- The catalog's scalar value is 9 cm. The FishBase SPECIES table (v25.04 snapshot) source reports a maximum adult measurement of 8 cm for this species, recorded as total length (TL). The taxonomic link follows a synonym to the FishBase SPECIES table (v25.04 snapshot) record for Nemanthias regalis (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
- Harem
- This species exhibits a fascinating social structure characterized by protogynous hermaphroditism, where all individuals are born female. A typical group consists of a single dominant male maintaining a harem of several females. If the dominant male is removed or dies, the largest and most dominant female will morph into a male to take his place. For the home aquarium, it is best to purchase a group of females and allow this natural transition to occur. Keeping multiple males usually results in fatal aggression unless the tank is massive.
- Feeding frequency
- 3-4 times daily
- Due to their incredibly active metabolism and natural grazing behavior, Pseudanthias regalis requires multiple feedings throughout the day. It is highly recommended to feed them small amounts at least three to four times daily. Infrequent, large feedings are poorly digested and can lead to malnutrition or starvation over time. Automated feeders can be very useful for dispensing small amounts of dry food while the aquarist is away. Consistent, frequent meals are the key to long-term success with this species.
- Bioload
- Pseudanthias regalis contributes a moderate amount to the overall bioload of a marine aquarium system. Due to their highly active nature and constant swimming, they require frequent feedings which indirectly increases the organic waste produced. Excellent filtration and regular water changes are strongly recommended to process these nutrients. Maintaining a robust protein skimmer will help manage the dissolved organics effectively. Proper husbandry ensures that the bioload remains manageable over the long term.
- Flow
- Strong
- This species originates from dynamic reef environments where strong water movement is a constant factor. Pseudanthias regalis thrives in aquariums that provide moderate to strong, turbulent water flow across the aquascape. Brisk currents simulate their natural habitat and encourage their natural schooling and feeding behaviors in the water column. Powerheads or wavemakers should be positioned to create broad, sweeping flow patterns rather than harsh, direct streams. Adequate flow also keeps particulate food suspended longer, giving them more time to feed.
- Jump risk
- Yes
- Like many highly active reef fishes, Pseudanthias regalis presents a moderate to high risk of jumping out of an open aquarium. They are easily startled by sudden movements, lighting changes, or aggressive tank mates, which can trigger a flight response. It is strongly advised to keep a tight-fitting lid or a custom mesh screen over the tank at all times. Even small gaps around equipment and overflow boxes should be covered to prevent tragic accidents. Taking these precautions is a simple but vital part of their husbandry.
- Reproduction
- Protogynous hermaphrodite
- Breeding Pseudanthias regalis in a home aquarium is exceptionally rare and presents significant challenges for even advanced hobbyists. They are pelagic spawners that release their eggs and sperm into the water column during synchronized mating rituals. The resulting larvae are microscopic and require highly specialized, perfectly sized live planktonic foods to survive. Furthermore, the larval stage is extremely long and sensitive to minute changes in water quality. Consequently, nearly all specimens available in the trade are wild-caught rather than captive-bred.
- Compatibility & tankmates
- Peaceful
- This species is generally considered completely reef safe and makes a stunning addition to mixed reef aquariums. Pseudanthias regalis will typically ignore corals, sessile invertebrates, and most motile invertebrates like ornamental shrimp. They are generally peaceful towards heterospecifics but can display significant aggression towards other Anthias species. It is usually best to keep them as the only Anthias species in the tank unless the aquarium is exceptionally large. Careful observation is needed when introducing new tank mates to ensure harmony.
- Tank level
- Middle/Bottom
- Throughout the day, Pseudanthias regalis will predominantly occupy the middle to upper levels of the water column. They are highly visible fish that love to hover above the reef structure, facing into the current to catch passing food. At night or when frightened, they will quickly dart into the rockwork to seek shelter in crevices and caves. Providing plenty of open swimming space alongside complex rock formations is essential for their comfort. Their active presence brings a wonderful sense of movement and life to the upper reef zones.
Scientific Parameters & Models
FishBase
Window to the official scientific data of the species
Data synced on: 06/15/2026
- Trophic level
- 3.3 ± 0.4 se
- Resilience
- High (less than 15 months)
- Phylogenetic uniqueness (PD50)
- 0.5312
- Bayesian Length-Weight
- a = 0.01413, b = 3
- VulnerabilityLow vulnerability (10 / 100)
Image gallery
Licensed images linked to the species or, when marked, to the closest representative taxon.
Related species
Recommendations grouped by close relatives, companion choices, and similar care.
