Black widow tetra

The black widow tetra reaches about 6 cm standard length and is one of the hardiest and most adaptable tetras in the hobby. It comes from the Paraguay and Guaporé River basins of South America, where it lives in slow-moving, well-vegetated waters. A school of six or more fits comfortably in a tank with a base of 75 by 30 cm (about 70 L). Temperature of 20–26 °C and pH 6.0–7.0 cover a wide range of conditions; the species tolerates cooler temperatures better than most tetras. The subdued grey body with bold black vertical bands and flowing fins makes a striking contrast against more colourful tankmates. Diet is omnivorous and unfussy — quality flake, granules, and regular live or frozen foods. It is generally peaceful and mixes well with livebearers, danios, rasboras, corydoras, and dwarf cichlids. Males are slimmer with more pointed dorsal and anal fins. Commercially bred colour variants include long-fin and gold forms. This species is an excellent choice for newcomers.