FishMarineAdvanced
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Sunset anthias
Pseudanthias parvirostris
A vibrant and delicate marine schooling fish displaying beautiful pink and yellow hues, requiring multiple feedings and strong water flow.
Water Temperature
22 - 27 °C
pH Value
8.1 - 8.4
Water type
Marine
Tank level
Bottom and middle
Adult size
7.5 cm
Minimum tank volume
>= 250 L
Minimum group
>= 4
KH
8 - 12 dKH
Species description
Geographical Origin and Habitat: Pseudanthias parvirostris is native to the central-western Indo-Pacific, ranging from the Maldives to the Solomon Islands, and extending north to southern Japan and south to Palau. It inhabits steep outer reef slopes, deep channels, and drop-offs exposed to strong currents at depths of 10 to 60 meters, swimming in loose groups.
Taxonomy and Morphology: Belonging to the family Serranidae, subfamily Anthiadinae, and genus Pseudanthias, this small fish features a slender, compressed body with large eyes and a terminal mouth. The caudal fin is deeply forked, developing long filaments in mature males. Adults reach a maximum size of 6 to 7.5 cm.
Social Behavior: Schooling fish with a strict haremic social hierarchy. In the aquarium, they must be kept in groups consisting of a single dominant male and several females (at least 4-5 specimens). The male actively patrols the group, displaying vibrant colors and performing minor chase rituals to maintain dominance over the harem.
Coloration and Sexual Dimorphism: Sexual dimorphism is highly pronounced. Females are mostly solid yellow or pinkish-orange. Dominant males display a breathtaking sunset-like coloration featuring magenta-pink bodies, a yellow or orange patch on the upper back, and iridescent violet or blue stripes on the head and fins.
Care, breeding and tankmates
Aquarium Setup: Requires a marine tank of at least 300 liters (approx. 80 gallons) to house a small school. The aquarium must have strong water movement provided by wavemakers to simulate reef currents. The aquascape should feature an open structure with plenty of caves and crevices for shelter at night.
Diet and Feeding: Demanding planktivore. They have a very high metabolism and must be fed small amounts multiple times a day (at least 3-4 times). Their diet should consist of high-quality fine frozen foods such as mysis, brine shrimp, krill, chopped clams, and lobster eggs. They will accept fine dry foods once acclimated.
Water Quality: Highly sensitive to poor water conditions. Maintain pristine reef parameters: temperature 23-26°C (73-79°F), pH 8.1-8.4, and specific gravity 1.022-1.025. A heavy-duty protein skimmer, efficient filtration, and weekly water changes are mandatory to handle the high bio-load from frequent feedings.
Compatibility and Cohabitation: Peaceful and entirely reef-safe. It is an ideal addition to stony or soft coral reef tanks. Coexists peacefully with other non-aggressive fish such as tangs, wrasses, gobies, and cardfish. Avoid keeping them with very aggressive or fast-feeding fish that could intimidate them and prevent feeding.
Aquarium Breeding: Breeding in home aquariums is extremely rare. They are protogynous hermaphrodites: all individuals are born female, and if the dominant male dies, the largest female in the group will transition into a male over a period of several weeks to assume control of the harem.
Risks and Diseases: Highly prone to shipping stress and acclimation issues. Starvation is a major risk if not fed frequently enough, leading to rapid muscle loss. They are susceptible to marine ich (Cryptocaryon) and velvet (Oodinium); a dedicated quarantine period is strongly recommended before tank introduction.
Geographic Origin and Distribution
Pseudanthias parvirostris is native to the central-western Indo-Pacific, ranging from the Maldives to the Solomon Islands, and extending north to southern Japan and south to Palau. It inhabits steep outer reef slopes, deep channels, and drop-offs exposed to strong currents at depths of 10 to 60 meters, swimming in loose groups.
Origin
Tropical oceans and reefsSouth and Southeast AsiaEast AsiaAustralia, New Guinea, and Oceania
Fish profile
- Temperament
- Peaceful
- The temperament of Pseudanthias parvirostris 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 parvirostris 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
- 5-7 years
- The Diadem Anthias typically has a lifespan of 5 to 7 years in captivity under proper, diligent care. To support their long-term health, they require stable water parameters, a stress-free environment, and high-quality nutrition. Ensuring a peaceful tank dynamic and keeping them in a harem group will help minimize stress, which is vital for their longevity. Excellent filtration and regular water maintenance are also essential to support their high feeding frequency.
- Adult size
- 7.5 cm
- The catalog's scalar value is 7.5 cm. The FishBase SPECIES table (v25.04 snapshot) source reports a maximum adult measurement of 7.5 cm for this species, recorded as standard length (SL). The taxonomic link follows a synonym to the FishBase SPECIES table (v25.04 snapshot) record for Pyronotanthias parvirostris (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
- Twice daily
- Due to their incredibly active metabolism and natural grazing behavior, Pseudanthias parvirostris 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 parvirostris 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 parvirostris 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 parvirostris 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
- Oviparous
- Breeding Pseudanthias parvirostris 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
- Reef safe
- This species is generally considered completely reef safe and makes a stunning addition to mixed reef aquariums. Pseudanthias parvirostris 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 parvirostris 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)
- 0.502
- 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.
