Black phantom tetra

The black phantom tetra inhabits the clear, plant-rich waters of the upper Madeira basin in Bolivia and western Brazil, with populations also found in the Pantanal wetlands. At just 3.6 cm standard length it is one of the smaller Hyphessobrycon species but makes up for its size with a dramatic colour pattern: the male's enlarged dorsal, pelvic and anal fins are jet black, while the female shows reddish fins and a deeper body. A long-finned ornamental strain is occasionally available.

Housing a group of eight to ten requires a tank with a footprint of at least 80 × 30 cm (72 litres). The water can range from 20–28 °C and pH 5.0–7.0, with the softer, more acidic end preferred for breeding. They show best colour in a dimly lit tank with dark substrate, floating plants and some leaf litter that encourages microbe colonies — a useful bonus if fry appear. They are not difficult to keep and adapt to a range of conditions as long as the water is clean and mature.

These tetras are omnivorous, accepting quality flakes and granules as a staple but needing live and frozen foods such as bloodworm, Daphnia and Moina for peak condition and colour. They are very peaceful and ideal for a well-researched community aquarium. Suitable tankmates include similarly-sized characins, hatchetfish, pencilfish, small corydoras and non-predatory cichlids.

Males form temporary dominance hierarchies and display more intensely in a group setting. The species is an egg-scatterer with no parental care. In a mature, planted tank small numbers of fry may appear spontaneously. For controlled breeding, set up a dimly lit spawning tank with a mesh bottom or fine-leaved plants, slightly acidic water and a slightly elevated temperature.