Luminescent System in a Myctophid Fish, Diaphus elucens Brauer

Abstract

THE myctophids, or lantern fishes, which migrate diurnally to the surface at dusk, are among the most common and widely distributed deep-sea fishes known. They emit a blue light from tiny dermal photophores¹ arranged in species-specific patterns over the ventral and lateral surfaces of the body. Certain species also possess a large nasal or caudal organ. Although hydrogen peroxide stimulates the photophores to luminesce², nothing is known about the molecular mechanism involved. We report that photophore extracts of the myctophid, Diaphus elucens Brauer, cross-react to give light with highly purified luciferin (substrate) and luciferase (enzyme) of the marine ostracod crustacean, Cypridina hilgendorfii. The Cypridina luminescence reaction is due to the oxidation of luciferin by molecular oxygen, catalysed by luciferase.