Cardinal Tetras (Paracheirodon axelrodi) are small, vibrant freshwater fish famous for their iridescent blue stripe and deep red lower body that spans the entire length of their torso.
Vs. Neon Tetra: Unlike Neon Tetras (where the red stripe only covers the back half), the Cardinal's red stripe extends all the way from head to tail.
 Size: Maxes out around 1.5–2 inches (3.8–5 cm).
 Behavior: Extremely peaceful schooling fish that swim together in tightly knit groups of 6 or more.
 Care: Thrives in warm, soft, slightly acidic water (73–81°F / 23–27°C, pH 5.5–7.0) with dense live plants and gentle lighting.