Bimaculatus Anthias - Male

The male Bimaculatus Anthias, Pseudanthias bimaculatus, is a striking saltwater fish prized for its intense pink, red, and lavender coloration. Mature males develop intricate magenta to violet markings across the body, contrasting fin accents, and the characteristic dorsal spotting associated with the species. Its active midwater swimming behavior and vivid coloration make it an impressive centerpiece for larger reef aquariums and fish-only marine aquariums.

Native to the Indo-West Pacific from East Africa through the Maldives to Indonesia, this species naturally inhabits reef-associated coastal drop-offs, often in deeper water. In captivity, it performs best in a mature, stable aquarium with excellent water quality, generous swimming space, and plenty of rockwork for shelter. Although generally compatible with peaceful community fish, adult males can be assertive toward other anthias, particularly competing males. 

Quick Care Guide

Care Level: Moderate
Minimum Tank Size: 125 gallons
Temperament: Semi-aggressive
Diet: Carnivore / Planktivore
Reef Safe: Yes
Region: Indo-West Pacific – East Africa, Maldives, and Indonesia
Scientific Name: Pseudanthias bimaculatus

Tank Requirements

Provide a mature, well-established aquarium with substantial open swimming space above and around the rockwork. Bimaculatus Anthias are active water-column swimmers, so a long aquarium with unobstructed areas is preferable to a densely packed aquascape.

Live rock should include caves, overhangs, and shaded retreats where the fish can shelter at night or withdraw from more assertive tankmates. Moderate to strong, well-distributed water movement and high oxygenation are beneficial, while efficient filtration helps compensate for the frequent feeding schedule anthias require.

A secure lid or mesh cover is strongly recommended because anthias can jump, particularly when newly introduced or startled. Adults can reach approximately 5–5.5 inches, making generous swimming room important for long-term housing. 

Diet and Feeding

In nature, Pseudanthias bimaculatus is adapted to feeding on small planktonic animals and crustaceans suspended in the water column. Captive specimens should receive a varied, protein-rich marine diet offered in small portions several times throughout the day.

Suitable foods include enriched mysis shrimp, enriched brine shrimp, copepods, frozen plankton, finely chopped marine seafood, high-quality frozen carnivore blends, and appropriately sized marine pellets. Foods that drift through the water column often produce the strongest feeding response. Aim for at least two to three small meals daily, with additional small feedings beneficial when practical. 

Temperament and Tankmates

Male Bimaculatus Anthias are generally compatible with unrelated community fish but may become territorial toward other anthias. A mature male can aggressively challenge another male, particularly when both are competing for the same swimming and sheltering areas.

They may be maintained as a single specimen or as one male with several females in an appropriately sized aquarium. Avoid keeping multiple mature males together unless the system is exceptionally large and provides extensive swimming space and visual barriers.

Suitable companions include clownfish, gobies, blennies, fairy and flasher wrasses, tangs, and other non-predatory marine fish. Extremely aggressive or predatory tankmates may intimidate anthias and interfere with their frequent feeding behavior. 

Reef Compatibility

The Bimaculatus Anthias is considered reef safe and does not normally damage or consume stony corals, soft corals, clams, or other sessile reef organisms. It is also generally compatible with ornamental shrimp, crabs, and snails.

As a natural planktivore, it will consume copepods and other very small planktonic organisms present in the aquarium, but this behavior does not normally present a concern in an established reef system.

Water Parameters

Temperature: 75–80°F
Specific Gravity: 1.024–1.026
pH: 8.1–8.4
Alkalinity: 8–12 dKH

Stable, consistent water conditions are more important than repeatedly adjusting the aquarium to achieve an exact number.

Common Considerations

• Requires frequent small feedings due to its natural planktivorous feeding strategy.

• Adult males can be territorial toward other anthias, especially other males.

• Provide a secure aquarium cover because anthias may jump when startled.

• A mature aquarium with open swimming space, strong oxygenation, and multiple sheltered retreats is recommended.

• Bimaculatus Anthias are protogynous, with dominant females capable of transitioning into males as social conditions change.