Description: Cardinal tetra fish have a horizontal bright, neon-like blue stripe and directly below it, a brilliant red stripe. These stripes run the entire length of their body, from the nose to the tail and take on an iridescent blue and green coloration as changes occur in the angle of light that strikes them. During the night and at times when no light hits the fish, they appear to be transparent and brown. The back and underbelly are whitish-silver. Males and females look the same, except females have a rounder belly. Cardinal tetras, as with other characids have an adipose fin (soft fleshy fin on the back located between dorsal and caudal fins).
Size: In the wild, these fish reach a total length of about 1.25 inches (3 cm) and weigh 0.004 ounce (0.13 gr). Females are slightly larger and wider than males.
Behavior: They are a schooling fish that can number into the thousands. Cardinal tetras are active during the day.
Diet: Cardinal tetra fish are omnivores, eating crustaceans, worms, insect larvae and some vegetable matter.
Reproduction: Females spawn in the rainy season, laying about 500 eggs which are fertilized by the males. Eggs fall onto plants or drop to the bottom. Because the eggs are light sensitive, only those in shaded areas will hatch. The eggs hatch in about three days. with the fry freely swimming four to five days later.
Habitat/range: They prefer slow-moving waters of the upper Orinoco and Negro Rivers in South America.
Status: Not listed by IUCN.