The phoenix tetra (Hemigrammus filamentosus) is a small fish that is currently considered endemic to Filadélfia in the drainage of the Rio Tocantins. This fish grows to an adult size of 1.4 to 1.9 inches long. Mature females are noticeably more stocky and rounded than the males. Adult males exhibit prolonged dorsal and anal fins.
Phoenix tetras should be maintained in an aquarium of 20 gallons or larger. A soft, sandy substrate (CS7538) is a good choice. Driftwood (ZM2000) and live or artificial plants may also be incorporated.
Phoenix tetras prefer a temperature of 76°F to 82°F, a pH of 6.0 to 7.5, and a hardness of 2 to 15°H. Be sure water is clean and well oxygenated.
The phoenix tetra is a very peaceful fish well suited to a planted aquarium. Good tank mates include other small tetras, livebearers, danios, rasboras, cory catfish, loricariid catfish, and dwarf cichlids. Keep them in groups of 10 or more.
Phoenix tetras are easy to feed fish accepting almost any appropriately sized food offered. In the aquarium they will readily accept flakes (AL165) and small frozen foods. For maximum color, growth, and health these fish will look their best when given probiotics (AL169) in addition to a balanced diet.