The Ruby Tetra is known only from the upper Rio Meta, a major tributary of the Rio Orinoco in Colombia. Few details are known of the natural habitat, but the favoured environments are thought to be sluggish or almost still, and crowded with dense vegetation and an abundance of leaf litter. The water is very soft and acidic, and stained a tea colour from the tannins in the decaying leaves and wood. The home aquarium should be mature, with a dark substrate and background and with driftwood and plenty of plant cover – both rooted and floating – in order…