Neon tetras originated from the clear water and blackwater streams and tributaries in the Orinoco and Amazon basin in Brazil, Columbia, and Peru. These are regions of blackwaters beneath dense forest canopies that allow very little light to get through. Neon tetras live in shoals mainly in the middle water layers and feed on worms and small crustaceans.

Neon tetras are now generally all captive-bred, with most coming from the Far East and eastern Europe. Several varieties of captive-bred specimens are now available. These include the long-finned neon tetra, though it is rather rare, as well as a golden strain that is basically a semi-albino variety, and a diamond neon tetra that appears sprinkled with metallic scales along the top portion of the body.

The neon tetra has a slender torpedo-shaped body that reaches no more than an inch and a half in length. What this fish lacks in size, it makes up for in color. From the tip of its nose to the adipose fin, the neon tetra has a bright neon blue stripe. It is believed this bright stripe makes them more readily visible to each other in blackwater conditions.

Like other colorful fish, the bright colors of the neon tetra will fade at night when it is resting, if it becomes alarmed, or when it is ill. At the fish store choose specimens that are active and robustly colored, as faded colors can be an indication of poor health. Always keep neon tetras in schools of a half dozen or more.