Squareback Anthias: Species Profile and Care Guide
Introduction
The Squareback Anthias (Pseudanthias pleurotaenia), also known as the Square Spot Anthias, is a stunning marine species admired for its vibrant colors and active swimming behavior. This fish, with its eye-catching square-shaped marking on the male’s body, is a favorite among marine aquarium enthusiasts. While its beauty is undeniable, Squareback Anthias require specific care to thrive, making them a more suitable choice for intermediate to advanced aquarists.
Species Overview
- Scientific Name: Pseudanthias pleurotaenia
- Common Name: Squareback Anthias, Square Spot Anthias
- Size: 8 to 10 inches (20 to 25 cm)
- Lifespan: 5 to 8 years in captivity
- Natural Habitat: Indo-Pacific coral reefs
- Diet: Carnivorous
Appearance and Behavior
The male Squareback Anthias is easily identified by its vivid pink body and the striking square-shaped purple spot on its side, which gives the fish its name. Females, on the other hand, are typically orange or yellow without the square marking. This species exhibits sexual dimorphism, meaning males and females look quite different.
Squareback Anthias are active, schooling fish that enjoy swimming in open water. In the wild, they live in large shoals, and they do best in captivity when kept in groups of at least three, with one male and multiple females. They can be shy when first introduced to a tank but become more confident as they acclimate to their surroundings.
Care Requirements
Tank Size
Squareback Anthias require a spacious tank due to their active swimming habits and social nature. A minimum of 125 gallons is recommended, especially if you are housing a group of them. In smaller tanks, they may become stressed and more prone to health issues.
Water Parameters
As reef fish, Squareback Anthias need stable, high-quality water conditions. They are sensitive to fluctuations in water parameters, so careful monitoring is crucial. The ideal water conditions are:
- Temperature: 72°F to 78°F (22°C to 26°C)
- pH: 8.1 to 8.4
- Salinity: 1.020 to 1.025 Specific Gravity
- Ammonia/Nitrite: 0 ppm
- Nitrate: Below 20 ppm (preferably closer to 10 ppm)
Aquascaping
In a tank setup for Squareback Anthias, provide plenty of open space for swimming as well as areas with rockwork or caves where they can retreat when feeling shy. They thrive in reef tanks with a moderate current and benefit from an aquascape that offers both hiding spots and areas of open water.
Feeding and Diet
Squareback Anthias are carnivorous, feeding primarily on zooplankton in the wild. In captivity, they need a varied diet of meaty foods. They may be reluctant to eat at first, so offering live or frozen foods such as brine shrimp, mysis shrimp, and copepods can help encourage feeding.
These fish have fast metabolisms and should be fed multiple small meals throughout the day. A high-protein diet is essential to keep them healthy. Over time, they may accept high-quality marine pellets or flakes, but frozen foods should still be a significant part of their diet to ensure proper nutrition.
Compatibility
Squareback Anthias are generally peaceful and can be kept with other non-aggressive fish. They do best in community tanks with other reef-safe species like tangs, wrasses, and gobies. Avoid keeping them with more aggressive species, which may outcompete them for food or stress them out.
Since Anthias are schooling fish, they thrive when kept in groups. It’s best to keep one male with several females, as males can become territorial with other males. In the absence of a male, the dominant female may change sex to take on the male role — a fascinating example of sequential hermaphroditism.
Breeding
Breeding Squareback Anthias in captivity is quite challenging, though not impossible. Like other Anthias species, they exhibit protogynous hermaphroditism, meaning all individuals are born female, and the dominant one will change into a male as needed. Spawning typically occurs in the late afternoon or evening, and males display elaborate courtship behaviors to attract females.
Successfully breeding these fish in an aquarium requires precise conditions, including a large, peaceful environment and careful attention to water quality. Raising the fry is even more difficult, as they require specialized care and tiny live foods like rotifers.
Common Issues and Health Concerns
Squareback Anthias are generally hardy once established, but they are prone to stress, especially during the acclimation process. Common health concerns include:
- Marine Ich (Cryptocaryon irritans): A parasitic infection that causes white spots and can be deadly if untreated.
- Malnutrition: Due to their fast metabolisms, Anthias require frequent feeding. Missing meals can lead to weight loss and weakness.
- Stress-Related Disease: Because they are sensitive to changes in water quality and tank conditions, poor water quality or aggressive tank mates can lead to stress and illness.
To prevent disease, it’s crucial to maintain pristine water conditions and provide a balanced diet. Quarantine any new fish before introducing them to the tank to avoid introducing parasites or diseases.
Final Thoughts
The Squareback Anthias is a stunning addition to any reef aquarium, thanks to its vibrant colors and active swimming habits. While they require more attention and care than some other marine fish, their beauty and fascinating social behavior make them a standout species. With proper care, these fish can thrive and bring life to your aquarium for years to come.
By following this care guide, you can enjoy the vibrant beauty and active nature of the Squareback Anthias in your marine setup.
