Squareback Anthias (Pseudanthias pleurotaenia)

The Squareback Anthias, also known as the Squarespot Anthias, is one of the most visually stunning anthias species, known for its vibrant colors and striking square-shaped patch on the male's side. Males are particularly impressive with their bright pinkish-purple bodies and a prominent lavender square on their flank, while females display a more subtle orange and yellow coloration. This species is a peaceful and active schooling fish, making it an ideal addition to large, well-established reef tanks.

Care Information

• Maximum Size: Up to 8 inches.
• Tank Size: 125 gallons minimum; Squareback Anthias thrive in larger tanks with plenty of open swimming space and rockwork for hiding.
• Diet: Carnivorous; requires a varied diet of meaty foods such as mysis shrimp, brine shrimp, and finely chopped seafood. High-quality frozen foods and pellets are also accepted. Anthias benefit from multiple feedings per day due to their high activity level.
• Water Temp: 72-78°F.
• Salinity: 1.020-1.025.
• Aggression: Peaceful; best kept in groups of one male with multiple females, as anthias exhibit a natural harem structure. They get along well with other peaceful tankmates.
• Skill Level: Intermediate; requires stable water conditions and a balanced diet, along with multiple daily feedings due to their active nature.
• Reef Compatibility: Reef-safe; does not harm corals or invertebrates, making it a great addition to large reef tanks.

Special Feature - Schooling Behavior
Squareback Anthias thrive when kept in groups, particularly with one dominant male and several females. Anthias are known for their social structure, where the dominant male may turn more vibrant, while females remain smaller and may eventually change sex to replace a lost male. Their active swimming and schooling behavior add life and movement to the aquarium.

Coloration

• Indo-Pacific Region: Males are known for their bright pinkish-purple coloration with a bold lavender square on their side, which becomes more vibrant during courtship. Females display a softer orange and yellow coloration, making the species visually striking in any tank. The sexual dimorphism adds visual interest and diversity​.

Typical Habitat

• Distribution: The Squareback Anthias is found in the Indo-Pacific region, where it inhabits deeper coral reefs. It prefers areas with strong water flow and plenty of hiding spots, where it schools in the water column and feeds on planktonic food.