Cardinal tetras are famous for their glowing blue and bright red stripes that run across their bodies. People often mix them up with neon tetras, but cardinal tetras have a bright red line that goes ...

In a biological twist few believed possible, researchers discovered that the giant discus fish produces a nutrient-rich mucus “milk” to feed its fry — behavior once thought unique to mammals.

Saltwater and freshwater fish tanks are enjoyable to have around the home. But is one better for beginner tank owners than the other?