The term Tetra covers several species of freshwater fish belonging to the Characidae family. They are very popular in aquariums due to their bright colors, peaceful behavior, and ease of maintenance.
 General characteristics:
 Size: From 2 to 7 cm depending on the species.
 Behavior: Peaceful and gregarious, must be kept in schools of at least 6 individuals.
 Some popular Tetra species:
 Neon Tetra (Paracheirodon innesi): Electric blue and bright red, very popular in aquariums.
 Tetra Cardinalis (Paracheirodon axelrodi): Similar to the Neon, but with more red.
 Lemon Tetra (Hyphessobrycon pulchripinnis): Translucent yellow with bright highlights.
 Black Phantom Tetra (Hyphessobrycon megalopterus): Black and silver with elegant fins.