Their most striking feature is the fluorescent blue stripe running ... for every centimeter of the adult fish. This means a 5-centimeter-long adult cardinal tetra would require a tank holding ...

colorful fish — red-and-blue neon tetras, for example — that look this way in the wild and are not dipped or dyed. You, as the owner, play a big part in how long your fish lives. On average ...

The Mexican tetra fish that lives in the rivers of Northern Mexico can heal its heart, while its cave-dwelling relative cannot A fish that can repair its heart may hold clues for future treatments ...