Deep-sea fish with enhanced vision: silver spinyfin (top), tube-eye (bottom) and lantern fish (middle). Illustration: Pavel Riha, University of South Bohemia, Ceske Budejovice, Czech Republic

How Fish See in the Deep Dark Sea

You can’t ask fish what they see. But you can study their genomes to get clues about how their eyes work. When scientists did that with some freaky deep-sea fish, they saw something surprising: Four species seem to have evolved four distinct and previously unknown systems for spotting color amid utter darkness more than a mile down.

Sunlight reaches about 3,280 feet into the ocean under the right conditions, but there is rarely any significant light beyond 656 feet, according to NOAA scientists. Image: NOAA
Female anglerfish, like this species discovered in 2015, dangle a bright lure off a bit of dorsal spine, then consume whatever is attracted to it. Photo: Theodore Pietsch, University of Washington
The two pearlside species studied. Photo: Fanny de Busserolles/University of Queensland

Explainer of things, independent health and science journalist, author, former editor-in-chief of LiveScience and Space dot com.

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