Juvenile parrotfish often have different color patterns compared to adults ... territorial disputes and courtship. Gobies are small fish that inhabit various environments, from coral reefs ...

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 ...

The two species of fish could look pretty similar on first glance, but they have slight variations in color and size. The Locust Fork darter is slightly bigger, but the fish are both fairly small ...