Etmopterus lantern sharks use coelenterazine as the substrate for their luciferin-luciferase bioluminescence system

Abstract

The lantern shark genus Etmopterus is a group of deep-sea bioluminescent fishes. Theyemit blue light mainly from the ventral body surface, and the primary biological functionis considered to be for camouflage by counterillumination. In this study, we detected bothcoelenterazine and coelenterazine-specific luciferase activity in the ventral photophoretissues. The results suggested that bioluminescence in lantern sharks is produced usingcoelenterazine as the substrate for the luciferin-luciferase reaction. Bioluminescence in cartilaginous fish has been reported in species of the squaliform familiesDalatiidae, Etmopteridae, and Somniosidae1,2. They have numerous tiny photophores mainlythroughout the ventral body surface, and its biological function is considered to becounterillumination, a strategy for camouflage from predators by cloaking their silhouette andmaking them indistinguishable from environmental downwelling light3,4.