A new study reveals that female anglerfish evolved glowing lures not just to catch prey but also to attract mates in the deep ocean. Researchers examined over 100 species of anglerfish in museum collections, creating a comprehensive family tree that traces the evolution of these specialized dorsal fins back 72 million years to the age of dinosaurs.

Alex Maile, a Ph.D. candidate at the University of Kansas, led the research that found bioluminescent anglerfish species are diversifying at higher rates than non-bioluminescent ones. The study, published in Ichthyology and Herpetology, suggests that the variety of glowing lures helps females signal to potential mates in the pitch-black waters thousands of feet below the surface, where food is scarce and visibility is near zero.

The research team used preserved specimens and DNA analysis to understand why these fish developed such diverse lure capabilities, from bioluminescent bacteria to chemical sprays. Tracey Sutton, a professor at Nova Southeastern University who was not involved in the study, called the dual-purpose evolution "an elegant solution" to the challenges of survival and reproduction in one of Earth's harshest environments. The findings provide crucial insights into how these remarkable creatures thrive in conditions that would seem impossible for most marine life.