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Bicolor Anthias

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Pseudanthias bicolor

Also known as: Bicolor Fairy Basslet, Sunset Anthias

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Description

Pseudanthias bicolor is a vibrant and moderately sized anthias species, highly prized in the aquarium trade for its striking coloration and active schooling behavior. It exhibits sexual dimorphism, with males typically displaying more intense coloration and elongated fin rays. These fish are protogynous hermaphrodites, meaning all individuals are born female and can later transition to male.

Physical Characteristics

Body shape
elongated
Coloration
Males typically exhibit a striking bicolor pattern: the anterior half of the body is bright yellow to orange-yellow, transitioning sharply to a magenta or purplish-pink posterior half. The dorsal fin often has elongated rays, and the caudal fin is deeply forked with elongated filaments. Females and juveniles are generally more uniformly orange-yellow to pinkish-orange, lacking the distinct bicolor demarcation and elongated fin rays of the males. Some individuals may display a prominent red or purple stripe running from the eye to the pectoral fin base.
Scale type
ctenoid
Mouth position
superior
Distinctive features
Sharp bicolor demarcation in males (yellow anterior, magenta posterior), Elongated dorsal fin rays and caudal fin filaments in mature males, Deeply forked caudal fin, Small, ctenoid scales
Dorsal fin
X spines, 16-17 soft rays; third dorsal spine often elongated in males.
Tail fin
Deeply forked with elongated filaments in males.
Pectoral fin
16-18 rays, typically clear to yellowish.
Distinctive fins
Pelvic fins are relatively long, reaching beyond the anal fin origin in males.

Identification Tips

Coloration (Males)

Look for the distinct yellow anterior and magenta/purplish-pink posterior body coloration. This sharp bicolor pattern is a key identifier for mature males.

Fin Elongation (Males)

Observe the elongated third dorsal fin spine and the filamentous extensions on the deeply forked caudal fin of males.

Coloration (Females/Juveniles)

Females and juveniles are more uniformly orange-yellow to pinkish-orange, lacking the sharp bicolor pattern. They also lack the elongated fin rays.

Habitat

Typically found hovering in schools over outer reef slopes and drop-offs, feeding on zooplankton.

Habitat

Water type
saltwater
Depth
10-60 meters (33-197 feet), occasionally deeper.
Environment
Found in clear, outer reef slopes and drop-offs, often associated with coral formations and rocky outcrops where they can find shelter. They typically hover in mid-water, feeding on zooplankton.
Geographic range
Indo-Pacific region, from the Maldives and Sri Lanka eastward to Samoa, north to southern Japan, and south to the Great Barrier Reef and New Caledonia.

Aquarium Information

  • Care level: intermediate
  • Temperament: peaceful
  • Diet: carnivore
  • Minimum tank size: 75 gallons
  • Temperature: 72-78°F (22-26°C)
  • pH level: 8.1-8.4
  • Hardness: 8-12 dKH
  • Compatibility: Generally peaceful with other reef-safe fish, but can be territorial with conspecifics or similar-looking species if not introduced properly or in sufficient numbers. Best kept in groups (harem) with one male and multiple females.
  • Special requirements: Requires a well-established reef aquarium with ample live rock for hiding and perching. A tight-fitting lid is essential as they are known jumpers. Needs multiple feedings per day of small, meaty foods to maintain health and coloration. Good water quality and strong water flow are crucial.

Wild Information

  • Conservation status: least concern
  • Seasonality: Breeding typically occurs year-round in tropical waters, with peak activity influenced by lunar cycles.
  • Market price: Moderate to high, depending on size and coloration.
  • Commercial importance: medium
  • Taste: Not typically consumed due to small size and value as an ornamental fish.
  • Texture: N/A
  • Nutritional value: N/A

Key Facts

Protogynous Hermaphroditebehavior

All Bicolor Anthias are born female and can later transition into males, typically when the dominant male in a harem is removed or dies. This is a common reproductive strategy among many anthias species.

Schooling Behaviorbehavior

These fish are typically found in large schools or harems, with one dominant male overseeing a group of females and juveniles. This social structure is crucial for their well-being in both the wild and captivity.

Zooplankton Feederbehavior

Pseudanthias bicolor are obligate planktivores, feeding primarily on zooplankton in the water column. Their superior mouth position is adapted for this feeding strategy.

Sexual Dimorphisminteresting

The striking difference in coloration and fin morphology between males and females is a clear example of sexual dimorphism, making it easy to distinguish sexes.

Safety Information

Safe
  • Safety level: safe
  • Venomous: No
  • Edibility: not recommended
  • Handling notes: No specific handling precautions are required beyond standard fish handling practices to minimize stress and injury to the fish. They are not venomous and do not possess any known harmful spines or toxins.

Similar Species

Dispar Anthias

Pseudanthias dispar

P. dispar males have a more orange-red anterior and a pinkish-purple posterior, but the demarcation is less sharp. The caudal fin lobes are also elongated, but the third dorsal spine is not as prominently elongated as in P. bicolor. P. dispar also tends to have a more pronounced red stripe through the eye.

Squareback Anthias

Pseudanthias pleurotaenia

P. pleurotaenia males are much larger and have a distinctive square-shaped dorsal profile and a prominent purple or magenta stripe along the flank. Their coloration is generally more pinkish-purple with yellow accents, not the distinct yellow/magenta bicolor of P. bicolor.

Lyretail Anthias

Pseudanthias squamipinnis

P. squamipinnis males are typically orange to red with a prominent red spot on the pectoral fin base and a deeply lyre-shaped caudal fin. They lack the distinct yellow anterior and magenta posterior body coloration of P. bicolor.

Scientific Classification

Kingdom
Animalia
Phylum
Chordata
Class
Actinopterygii
Order
Perciformes
Family
Serranidae
Genus
Pseudanthias
Species
bicolor

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