Typically, tetras have compressed, diamond-shaped bodies with a small adipose fin located between the dorsal and caudal fins. They exhibit a wide range of colors and patterns, with some species displaying iridescent hues or distinctive markings. Most tetras are small, generally measuring between 2.5 to 5 centimeters in length, making them suitable for community aquariums.

In their natural habitats, tetras inhabit clear and blackwater streams and rivers with dense vegetation. They are schooling fish that thrive in groups, displaying synchronized swimming behaviors that enhance their visual appeal and provide a sense of security. As omnivores, tetras feed on small invertebrates, plant matter, and algae. In captivity, they adapt well to a diet of high-quality flake foods, supplemented with live or frozen options like brine shrimp and daphnia.