Save Our Seas Foundation 83d ago

The eyes of long-spined porcupinefish are quite the sight (pun intended), as with most nocturnal fish. In the shallow coral reefs where they live, the  corneal iridescence (or the metallic sparkle that can be seen in their eyes) significantly increases their visual range as they hunt for snails, sea urchins and hermit crabs under the cover of darkness. At night, this iridescence lessens to allow more light into the eye, while on bright, sunny days, it limits the amount of light that can enter, allowing them to see even in the bright daylight conditions of their shallow reef home.