Juvenile parrotfish often have different color patterns compared to adults ... territorial disputes and courtship. Gobies are ...

The devil’s hole pupfish is small, reaching lengths of up to 1.2 inches, and colors vary between age and sex – the males exhibit a bright, metallic blue while juveniles and females are closer ...

If your aquarium feels a little blah, maybe it’s missing some bold personalities. We’re talking fins that flash like neon signs and colors that could outshine a fashion runway.

For years, scientists felt like the fish they were watching watched them back. A new study suggests they can recognize a diver's outfit.