Neon tetras are some of the most popular aquarium fish in the world, and for good reason! These little guys are hardy, beautiful, and can tolerate a wide range of water parameters. Here are ten cool facts about neon tetras.

1. Neon tetras owe their bright coloring to "blackwater" regions in which they evolved. The waters in their native habitat are full of tannins, which make it hard for fish to see one another. They developed their bright colors so they can see each other and school together in these tea-stained waters.

2. There are several other fish called "neon tetras," but these are different species, not color variations. The green neon tetra is closely related but has a green "neon" stripe instead of blue. The red neon tetra, or cardinal tetra, has a longer red stripe that extends across its body. Black neon tetras are black with a glowing silver stripe.

3. Neon tetras are susceptible to a common disease that is (not too creatively) known as neon tetra disease or NTD. Although it's extremely common, there is no cure.

4. Believe it or not, neon tetras are members of the same family as piranhas!

5. A common tankmate for the neon tetra is the glowlight tetra, which is similar in appearance but has a bright golden stripe instead of blue or red coloration. A school of glowlight tetras makes a beautiful complement to a school of neon tetras.

6. Neon tetras must be kept in schools of six or more, and do best in schools of ten or more. Neon tetras kept alone become stressed and depressed, which may cause them to die prematurely.

7. If neon tetras are kept alone or in groups that are too small, they may try to school with similar-looking fish, like glowlight tetras, green neon tetras, and cardinal tetras.

8. Neon tetras' colors tend to fade when they are stressed. You might notice that their iridescent stripes look less flashy when tank conditions are poor or when they are kept in small numbers.

9. Neon tetras are often confused with Glofish, painted glass fish, and other fish that have been modified by human intervention, such as genetic modification and tattooing. However, their bright coloration is entirely natural.

10. An estimated 1.8 million neon tetras are imported into the U.S. every single month. That's 22 million a year!

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