Lanternsharks produce and perceive bioluminescent light in order to communicate, find prey, and camouflage themselves against predators in the mesopelagic twilight zone.
The mesopelagic twilight zone is 200-1000 meters deep in the sea - a vast, dim habitat, where, with increasing depth, sunlight is progressively replaced by point-like bioluminescent emissions. To better understand strategies used by bioluminescent predators inhabiting this region that help optimize photon capture, the authors of a new study analyzed the eye shape, structure, and retinal cell mapping in the visual systems of five deep-sea bioluminescent sharks, including four Lanternsharks (Etmopteridae) and one kitefin shark (Dalatiidae).