A deepwater fish with ‘lightsabers’ – dorsal spine-associated luminescence in a counterilluminating lanternshark

We report the discovery of light organs (photophores) adjacent to the dorsal defensive spines of a small deep-sea lanternshark (Etmopterus spinax). Using a visual modeling based on in vivo luminescence recordings we show that this unusual light display would be detectable by the shark's potential predators from several meters away. We also demonstrate that… (More)