Banded Astyanax (Astyanax bimaculatus) — > 3cm

Overview

The Two-Spot Astyanax (Astyanax bimaculatus) is a hardy, peaceful South American tetra that brings classic characin charm and active movement to community aquariums. Native to freshwater systems across tropical and subtropical South America, this robust schooling fish is prized for its adaptability, ease of care, and engaging behavior. Available for sale UK-wide, the Two-Spot Astyanax is an excellent choice for aquarists seeking a resilient, mid-water schooling species that thrives in a variety of setups.

Appearance and Coloration

Astyanax bimaculatus displays a sleek, silver body with two distinctive dark spots: one behind the gill cover and another near the caudal peduncle. The fins may show subtle yellow or reddish hues, particularly in well-conditioned individuals. This species has a typical tetra profile with a streamlined body, forked tail, and large, expressive eyes. Males and females are similar in appearance, though females may be slightly fuller-bodied.

Natural Habitat

The Two-Spot Astyanax is widespread across tropical and subtropical freshwater systems in South America, including rivers, streams, and floodplain habitats. These environments feature soft to moderately hard water, abundant vegetation, and seasonal fluctuations in water level and flow. The fish form large schools in the wild, sheltering among plants and driftwood while foraging for insects, crustaceans, and plant matter.

Aquarium Setup

A minimum 150-litre aquarium is recommended for a school of Two-Spot Astyanax. Provide open swimming areas combined with planted zones using robust species like Vallisneria, Amazon Sword, or Anubias. Driftwood and smooth rocks create naturalistic hiding places and territorial markers. Moderate to strong filtration maintains water clarity and quality, and a secure lid is essential, as this species is an active swimmer that may jump.

Water Parameters

Maintain soft to moderately hard water with pH 5.5-7.5 and temperatures between 22-28°C. General hardness (GH) of 5-12 dGH is ideal. The Two-Spot Astyanax is highly adaptable and tolerates a range of water conditions, making it suitable for diverse community setups. Perform weekly water changes of 20-25% to control nitrate and maintain stable parameters. Avoid extreme pH swings or prolonged exposure to poor water quality.

Feeding and Diet

Astyanax bimaculatus is an omnivore that thrives on a varied diet. Offer quality flakes or micro-pellets as a staple, supplemented with frozen and live foods such as daphnia, brine shrimp, bloodworms, and cyclops. Occasional vegetable matter or spirulina-based foods provide balanced nutrition and enhance coloration. Feed 1-2 times daily in small portions, ensuring food is consumed promptly to prevent water quality degradation.

Behaviour and Personality

The Two-Spot Astyanax is a peaceful, active schooling fish that thrives in groups of 6-8 or more. Shoaling behavior is most pronounced in larger schools, with fish moving together in coordinated patterns. This species occupies the mid to upper water column and is constantly on the move, making it an engaging addition to community tanks. While generally non-aggressive, large schools may intimidate smaller, more timid species.

Tank Mates

Ideal tank mates include other robust, similarly sized peaceful schooling fish such as larger tetras, Corydoras catfish, peaceful medium-sized loricariids, and peaceful, non-aggressive cichlids of similar size. Avoid large predatory fish, fin-nipping species, very slow or long-finned fish, highly aggressive cichlids, and tiny fry or shrimp that may be eaten. The Two-Spot Astyanax coexists well with a variety of peaceful to semi-robust community fish.

Breeding

Astyanax bimaculatus is an egg scatterer that spawns readily in planted or fine-leaved setups. Breeding is most successful in a separate spawning tank with soft, slightly acidic water (pH 6.0-6.5) and abundant fine-leaved plants or spawning mops. Condition adults with live foods, then introduce a pair or small group. Remove adults immediately after spawning to prevent egg predation. Fry hatch in 24-48 hours and require infusoria or liquid fry food initially, graduating to baby brine shrimp as they grow.

Why Buy from Tropical Fish Co

Tropical Fish Co specializes in healthy, robust South American tetras sourced from reputable suppliers and quarantined for your peace of mind. We provide expert guidance on tank setup, water chemistry, and compatible stocking to help you create a thriving community aquarium. With fast, reliable delivery across the UK and a commitment to sustainable fishkeeping, Tropical Fish Co is your trusted partner for quality freshwater fish.