Which fish looks like a car driving at night?

Imagine scuba diving through a tropical reef late at night. You are drifting past the dark corals when suddenly two lights turn around a corner and head straight for you! They look exactly like the headlights on a car, but they actually belong to a flashlight fish!

Flashlight fish spend most of their time in deep water, but they move up into coral reefs at night. They get their names from an organ beneath each eye that actually glows in the dark! The glow actually comes from a kind of bacteria that live within these organs, and share a useful relationship with the fish. The bacteria get all the nutrients they need from the fish, and in return, the glow they produce helps attract plankton and tiny fish that are eaten by the flashlight fish.

Just like headlights on a car, the glowing organs can be “turned off” by a membrane the fish can pull across them. It can beckon to fish by blinking one “headlight” after another, just like a turn signal, and if a predator threatens the flashlight fish, it quickly covers its glowing organs and retreats into the dark!

Sometimes flashlight fish gather together in large schools, and their glow can be visible from the surface. Fishermen can follow the trail of glowing fish to help them steer through narrow reef passages in the dark!