Why do deep-sea fish glow?
Show answer & explanation
Answer: Bioluminescence for survival
From eating glowing bacteria — Wrong. While some fish do host light-producing bacteria, many create light themselves through chemical reactions in specialized organs called photophores.
Bioluminescence for survival ✓ — Correct! Deep-sea fish use bioluminescence to find mates, lure prey, confuse predators, or camouflage against faint surface light. In the pitch-black deep ocean, making your own light is a powerful survival tool!
Reflection of surface light — Wrong. No sunlight reaches the deep sea—it's completely dark below 1,000 meters. Fish must produce their own light through chemical reactions called bioluminescence.
Go deeper: Bioluminescence
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