Why do anglerfish have lights?

Answer: Luring prey within reach

Communicating with other fish — Wrong. Deep-sea anglerfish are solitary and use light for hunting, not social communication. Males find females by scent, not light signals.

Warning predators to stay away — Wrong. The light attracts rather than repels. It's a hunting tool that draws curious prey close enough to ambush.

Luring prey within reach ✓ — Correct! Female anglerfish have a bioluminescent lure (modified dorsal spine) dangling above their mouths. In pitch-black deep ocean, curious prey investigate the glowing light—and get eaten! The glow comes from bacteria living in the lure that produce light. It's fishing with a living lightbulb!