Care
The Broken-Line Tetra is known only from tributaries of the Rio Paraguay in Brazil. This is an attractive, peaceful shoaling species, ideal for good-sized, mature softwater aquaria. The tank should be furnished with plenty of driftwood to create lots of shady areas, and the tannins that are gradually released from the wood should help to acidify the water whilst giving it a natural, clear tea-colour. Peat filtration can also help in this respect. Although little detailed information is available regarding the natural habitat of this species, it is unlikely that aquatic plants are found in any great abundance. However, in the home aquarium, these fish seem very at home in tanks with areas of dense, robust planting and a moderate water flow. Lighting should not be too bright (tannins and floating plants can help to diffuse brighter lighting), and darker substrate and background choices will help to show off their exquisite colouration. Broken-Line Tetras should always be maintained in good sized groups, 6 would be the minimum recommended, 10+ would be better. Not only will the fish feel more secure, but this will result in a far more effective, natural-looking shoal. Ideally, tankmates will also be small and peaceful, and could include Corydoras catfish, small dwarf cichlids such as Apistogramma or Mikrogeophagus, some of the smaller Loricariidae (suckermouth catfish), and many of the more peaceable Botiid loaches. Broken-Line Tetras are highly sought after, although unfortunately rarely imported. You may also see this fish labelled up as Ulrey's Tetra, or, erroneously as Astyanax sp. Lago Tefe.
Feeding
Offer a varied diet including a good quality flake, micropellets, and small frozen foods such as bloodworm, white mosquito larvae, vitamin-enriched brineshrimp, and daphnia.
Breeding
Challenging to breed. In the confines of a well planted community tank, you may see small numbers of young appear from time to time. However if you wish to raise a good number of fry, a separate, softwater breeding aquarium should be set up for the purpose. It is thought that well-conditioned specimens can be coaxed into breeding by "overwintering" at a slightly cooler temperature, then gradually and carefully increasing the temperature and frequency of partial water changes. Clumps of Java moss or a few bunches of fine-leaved plants should be added to the breeding tank to give the fish somewhere to scatter their eggs, and very gentle filtration should be provided via an air-driven sponge filter (a small bag of peat can be incorporated here). No dedicated lighting should be used, as eggs and fry are rather light sensitive. The parents should be removed immediately after spawning ceases as they will predate on the eggs. Some aquarists like to use a fine mesh in the tank so that the scattered eggs can fall to safety, away from the attention of the adult fish. Ideally try and keep the tank in darkness once eggs have been scattered, to protect them and the resultant sensitive young fry from being damaged by bright light. The eggs should hatch within 24-36 hours (temperature dependent) and the young will initially feed from their yolk sacs. Once free-swimming (usually after 3-4 days), microscopic foodstuffs such as infusoria/Paramecium should then be offered, followed by baby brineshrimp (Artemia nauplii) and microworm as they grow.
