Go for a dive in the Indo-Pacific at night, and you may see what look like little blue flashlights flitting about in the dark.
![](https://tigerblue.info/wp-content/uploads/2023/03/5dc41b2a78cf53ff3384f8ae_header-flashlight-fish.jpeg)
But there’s nothing supernatural afoot—only a quirk of biology. That neon-blue glow belongs to splitfin flashlight fish and their built-in headlamps.