Squareback Anthias - Male
Squareback Anthias - Male
Goes well with:
FAQs Answers to the most common questions.
Is Pink Square Anthias best kept as a single fish, or does it need a group?
It is much better kept in a small harem or group, not alone. Like most anthias, the most stable setup is one dominant male with 3–6 females. A lone Pink Square Anthias often becomes timid, refuses food, or fades in color. If kept in a pair, make sure one is clearly male and the other is female; two similar-sized individuals may fight.
What foods reliably get Pink Square Anthias feeding in captivity?
They usually do best on frequent small feedings of meaty planktonic foods: enriched mysis, copepods, baby brine shrimp, finely chopped krill, and high-quality marine pellets designed for planktivores. The key is variety and frequency. Offer food 2–4 times daily if possible. Newly imported fish often start with live or frozen copepods and baby brine shrimp before accepting pellets.
How can I tell if a Pink Square Anthias is male or female?
Males are typically more intensely colored, more assertive, and often show more elongated dorsal, anal, or caudal fin extensions depending on the individual. Females are usually smaller, rounder in profile, and less vivid. In a group, the largest, most dominant individual often transitions into male if no male is present.
What tank setup suits Pink Square Anthias best long-term?
They do best in a mature reef-style aquarium with strong water movement, high oxygenation, and plenty of open swimming space plus some sheltered rockwork. Stability matters more than minimalism: low nitrate, no sudden salinity swings, and excellent filtration are important because they are sensitive to poor water quality. A tight-fitting lid is also important, since anthias are jumpers.
Why do Pink Square Anthias sometimes waste away even when they seem to be eating?
This is a common anthias problem and usually comes from not feeding often enough, foods being too large or too rich, or the fish being outcompeted at meals. They burn energy quickly and need frequent access to small, nutrient-dense foods. Another issue is internal parasites or shipping stress, especially in newly imported specimens. If one is eating less, isolate it if needed, increase feed frequency, and watch closely for rapid weight loss behind the head and belly.
All listed sizes are approximate, not guaranteed, and may vary slightly.
The Squareback Anthias (Pseudanthias pleurotaenia) is a planktivore with a magenta-to-violet body. Males have a golden-orange square patch and subtle fin elongation that distinguish them from females. This listing is for a male.
In the wild, these anthias form loose aggregations over current-swept reef slopes and pick zooplankton from the water column. In an established aquarium, a healthy specimen typically cruises open water in short, darting bursts. It requires frequent feeding, stable water quality, and experienced care.
Quick Care Guide
Care Level: Difficult
Minimum Tank Size: 50 gallons
Temperament: Semi-Aggressive
Diet: Carnivore
Reef Safe: Yes
Region: Western Pacific
Scientific Name: Pseudanthias Pleurotaenia
Tank Requirements
Provide ample open swimming room, with a larger footprint if additional anthias may be added. Long, wide aquariums suit their cruising behavior better than tall, narrow tanks. Arrange caves, ledges, and branching rockwork to break lines of sight and provide shelter.
Strong, non-turbulent flow and excellent oxygenation support its plankton-feeding behavior. Use a secure, tight-fitting lid because anthias may jump when startled or newly introduced. Maintain stable, pristine conditions and avoid sudden changes in salinity or temperature.
Diet and Feeding
As a planktivorous carnivore, it feeds continuously on small zooplankton in the wild. One daily feeding isn't enough. Offer small portions of mysis shrimp, enriched brine shrimp, and finely chopped meaty foods two to four times per day.
Rotate copepods, small pieces of krill, and vitamin-enriched frozen blends to support color and body condition. Marine vitamin supplements can help meet its high energy demands. Watch for a sunken belly or hollowness behind the head, and target feed when faster fish take most of the food.
Temperament and Tankmates
Assertive behavior usually centers on territory and feeding. Males can push conspecifics, establish a clear group hierarchy, and spar over food or preferred shelter. A single specimen, bonded pair, or harem of one male with several females can work when space allows.
Suitable tankmates include gobies, blennies, cardinalfish, clownfish, and peaceful wrasses. Avoid large tangs, triggerfish, dottybacks, aggressive wrasses, and other boisterous competitors. A solitary individual can thrive, but cramped or aggressive surroundings may cause withdrawal and poor feeding.
Reef Compatibility
It is reef safe and does not pick at stony or soft coral polyps. Sessile invertebrates are generally ignored while it focuses on food drifting through the water column.
Ornamental shrimp, snails, crabs, and clams are safe with it. Its diet centers on meaty planktonic foods instead of grazing on tankmates. Competition at feeding time is the main reef-tank concern, as faster or bolder fish may take the available food.
Water Parameters
Temperature: 75–80°F
Specific Gravity: 1.024–1.026
pH: 8.1–8.4
Alkalinity: 8–12 dKH
Keep these parameters stable and avoid rapid changes.
Common Considerations
- Frequent Feeding: Provide small meals two to four times daily, as once-daily feeding or competition from faster fish can quickly lead to weight loss.
- Quarantine: Quarantine for four to six weeks to confirm steady weight gain and screen for parasites before adding it to the display.
- Jumping Risk: Keep a tight-fitting lid in place because it may jump when startled or during early acclimation.
- Social Structure: Keep singly, as a bonded pair, or in a harem with one male and several females. Crowding multiple males can cause persistent aggression.
- Care Consistency: An established reef system and dependable feeding routine are important because inconsistent care and poor water quality are not tolerated.
