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Narrator: Listen to part of a lecture in a biology class. Professor: Today we're going to talk about a fascinating adaptation in certain deep-sea fish: bioluminescence. Now, many of you know that bioluminescence is the production and emission of light by living organisms. But in the deep ocean, where sunlight doesn't penetrate, this ability is not just for show. It serves critical survival functions. For example, some species use counter-illumination. They produce light on their ventral side, or their belly, to match the faint light coming from above. This makes them invisible to predators swimming below, because their silhouette blends with the background. Another use is for communication. Some fish have light organs that flash in specific patterns to attract mates, much like a visual language. And then there's the classic lure, like the anglerfish, which uses a glowing appendage to attract prey right to its mouth. So, bioluminescence isn't just a pretty light show—it's a suite of evolutionary tools for survival in a dark world.
❓ 题目 What is the main purpose of counter-illumination in deep-sea fish, according to the professor?

✅ 正确答案

To hide from predators by blending with the light from above

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