Blue Emperor Tetra Care Guide - Aquarium Setup, Diet & Breeding

The Blue Emperor Tetra is a small, elegant characin with a dark bluish to violet body, a subtle metallic sheen and a distinctive dark stripe running along the side. Its fins may show yellow, orange or reddish tones, while the eye often has a noticeable blue-green sparkle. Males are typically more intensely coloured than females.

This species is peaceful, active and sociable, spending much of its time in the middle levels of the aquarium. In a group, males may display to one another by spreading their fins and intensifying their colours, but these interactions are normally harmless and add movement to a planted community aquarium.

In the wild, Blue Emperor Tetras inhabit quiet forest streams and backwaters influenced by fallen leaves, branches and dense vegetation. Leaf litter and submerged roots can release tannins into the water, creating the soft, warm, amber-coloured conditions associated with South American blackwater habitats.

Although sometimes less widely seen than other small tetras, Inpaichthys kerri has become a valued aquarium fish because of its attractive colour, manageable size and generally peaceful temperament. It looks especially impressive in a planted aquarium with subdued lighting and a dark background.

Blue Emperor Tetras are native to Brazil in South America, where they occur in tributaries and slow-moving forest waters of the upper Madeira River basin, including the Rio Aripuanã region. Their natural habitats are often shaded, tannin-stained blackwater environments with dense marginal vegetation.

A group of Blue Emperor Tetras should have at least a 60-litre aquarium, with a footprint of approximately 60 by 30 cm or larger. Use a dark, fine substrate with dense planting around the sides and rear, leaving open swimming space through the centre. Driftwood, roots, leaf litter and floating plants create useful shelter and replicate their shaded forest habitat. Gentle filtration, subdued lighting and stable, clean water are preferable; a small amount of peat or botanicals may be used to create natural tannin-stained conditions if water chemistry is monitored carefully.

Males reach approximately 3.5 cm (1.4 inches), while females can grow to around 4.5 cm (1.8 inches) in length.

Blue Emperor Tetras are omnivores and should receive a varied diet of quality small flakes or micro-pellets supplemented with frozen or live foods. Daphnia, baby brine shrimp, cyclops and finely chopped bloodworm are suitable additions and can help maintain colour and condition. Offer small portions once or twice daily, with food reduced to a size they can readily swallow.

Blue Emperor Tetras are suitable for peaceful community aquariums and can be kept with other similarly sized tetras, rasboras, pencilfish, small danios, peaceful Corydoras and small, non-aggressive Loricariid catfish. They also mix well with other calm South American species such as small peaceful Apistogramma, provided the aquarium offers sufficient space and cover. Avoid large or predatory fish, fin-nipping barbs and boisterous tankmates that may intimidate them or outcompete them for food.

Blue Emperor Tetras are egg-scattering fish that breed most readily in a separate, dimly lit spawning aquarium containing soft, slightly acidic water and fine-leaved plants or spawning mops. Condition males and females with plenty of small live or frozen foods, then introduce them as a breeding pair or small group. The adults may eat the eggs, so remove them after spawning or protect the eggs with a mesh barrier. Eggs generally hatch in about 24 hours, and the tiny fry can be raised initially on infusoria or other suitably fine liquid food before progressing to newly hatched brine shrimp.

Males are generally slimmer and more vividly coloured, with a stronger blue sheen and more elongated, often pointed fins. Females are usually deeper-bodied, paler and slightly larger, particularly when carrying eggs.