Broken-Line Tetra Care Guide - Aquarium Setup, Diet & Breeding

The Broken-Line Tetra is a small, elegant characin with a silvery body, translucent fins and a distinctive dark lateral marking that appears as a broken line along the flank. A warm golden or amber sheen can show through the body, particularly when the fish is settled and displaying well. Its modest size and understated pattern give it a refined appearance rather than the intense colours seen in some closely related tetras.

This is an active but generally peaceful schooling fish. In a group, the tetras move through the middle levels of the aquarium, maintaining loose formation while regularly breaking away to investigate their surroundings. Their natural confidence and liveliness become more apparent when they are kept in an appropriately sized shoal.

In the wild, Broken-Line Tetras inhabit freshwater streams and tributaries in southeastern Brazil. These environments may contain submerged roots, fallen leaves and areas of marginal vegetation, creating a mixture of open swimming space and shaded cover. Seasonal changes can alter water flow, clarity and the amount of organic material in the water.

Hemigrammus ulreyi remains less common in the aquarium trade than many familiar ornamental tetras, but it is valued by enthusiasts for its natural appearance and peaceful character. A healthy group provides subtle movement and attractive schooling behaviour in a South American community aquarium.

Broken-Line Tetras are native to Brazil in South America. They are associated with clear to lightly stained freshwater habitats and slow-moving tributaries within the Paraná River basin.

A group of Broken-Line Tetras should have at least a 60-litre aquarium, ideally measuring around 60 cm long by 30 cm wide or more so they have uninterrupted swimming space. Use a dark or natural fine substrate with driftwood, smooth roots and live plants arranged to provide shaded retreats around the edges while leaving an open central area. Floating plants, leaf litter and subdued lighting can create a more natural, gently dappled environment, while gentle filtration and stable, well-maintained water are important.

Up to about 4 cm (1.6 in) in total length. Females are usually slightly deeper-bodied and may be marginally larger than males.

Broken-Line Tetras are omnivores and do best on a varied diet of high-quality small flakes or micro-pellets, supplemented with frozen or live foods such as baby brine shrimp, daphnia, cyclops and mosquito larvae. Small portions offered regularly are preferable to large meals, and occasional vegetable-based ingredients can contribute useful dietary variety. Food should be fine enough for their small mouths.

Broken-Line Tetras suit peaceful community aquariums and can be kept with similarly sized tetras, peaceful rasboras, small danionins, pencilfish, Corydoras, otocinclus and other calm South American community fish. They should be kept away from large, aggressive or predatory species, fin-nippers and boisterous tankmates that may intimidate them or outcompete them for food. Their own group should be large enough to encourage natural, confident behaviour.

Broken-Line Tetras are egg-scattering spawners that breed most readily in a separate, mature breeding aquarium with soft, slightly acidic water and subdued lighting. Add a conditioned pair or small group, together with fine-leaved plants or spawning mops for the eggs to fall among. Adults may eat the eggs, so remove them after spawning or protect the eggs with a mesh divider. The eggs usually hatch in roughly 24 to 36 hours, and the tiny fry need infusoria or another suitably fine first food before progressing to larger foods.

Females are generally fuller through the abdomen, especially when carrying eggs, while males tend to be slimmer and slightly more streamlined. The differences are subtle, and sexing young or unconditioned fish can be difficult.