The neon tetra is a freshwater fish native to Brazil, Columbia and Peru. It is very small and only grow to about 1 inch (2.5 cm) in length. It is most notable for its iridescent blue and red stripes that appear to glow. The blue lines cover each side horizontally from nose to the adipose fin, while the red stripes runs along from the middle to bottom of the caudal fin. Its unique appearance has made the neon tetra one of the most popular aquarium fish.
In addition to its appearance, the neon tetra is also a popular fish for aquariums because it is extremely hardy and able to withstand a variety of water conditions. Water temperature can range anywhere between 68 and 80 degrees Fahrenheit (20 to 27 degrees Celsius), and the pH can vary from 5.0 to 7.0.
Gravel or rock substrate is suitable, and as long as it has plenty of hiding spots to reduce stress it should be comfortable in most aquariums. Since it is very small, it does not need a large aquarium, and it is not aggressive to any other fish. Care must be placed in choosing tank mates though for the safety of the neon tetra. Its small size and docile nature can make it the ideal food for larger, more aggressive fish.
All tetras are schooling fish, and should be kept in groups of five or more. In the wild, the neon tetra will most often eat plants and small animals such as worms and insects, so it can be fed a variety of aquarium food. In an aquarium it will eat nearly anything, and can survive on flake food or meaty foods like brine shrimp. Under ideal conditions the fish can live for up to 10 years.
Neon tetras are unfortunately susceptible to a deadly fish disease called pleistophora. The neon tetra is so much associated with the illness that it is frequently just called "Neon Tetra Disease." Caused by a parasite, the disease first causes discoloration and restlessness before advancing and causing cysts and other scale abnormalities. It eventually leads to a curved spine and more often than not, death. There is no cure or viable treatment for the disease. It is important that all fish, not just neon tetras, are introduced to an aquarium slowly, and preferably put in a quarantine tank for a week or so, before being introduced to an aquarium.