Why do anglerfish have glowing lures? It might be sex: Species proliferated after evolving bioluminescence, possibly because mates could find each other more easily.

The article focuses on the evolutionary role of bioluminescent lures in deep-sea female anglerfish, suggesting that these glowing lures not only attract prey but also help males locate mates, potentially driving a rapid diversification of anglerfish species. Research analyzing DNA, anatomical traits, and fossils indicates that bioluminescent lures evolved between 34 and 23 million years ago, with longer lure spines possibly preventing the female’s body from being illuminated. Male anglerfish, which lack lures and are much smaller, use enhanced sensory organs and vision to find females, after which they permanently attach to them for reproduction. This unique reproductive strategy has contributed to deep-sea anglerfishes comprising 43% of all living anglerfish species. [Extracted from the article]