Bioluminescence in the Marine Teleost, Porichthys notatus, and its Induction in a Non-luminous Form by Cypridina (Ostracod) Luciferin

Abstract

THE midshipman fish, Porichthys notatus Girard, 1854, of wide distribution along the Pacific Coast from Alaska to Baja California, Mexico^1–3, is characterized by more than 700 tiny dermal photophores, arranged in rows over the body surface⁴ (Fig. 1). Except for specimens from Puget Sound, Porichthys photophores luminesce spontaneously only during courtship⁵. Luminescence may be evoked artificially by electrical stimulation or injection of epinephrine, norepinephrine, or amphetamine^6–9. Strum^10,11 reports that Puget Sound fish do not luminesce, even when injected with epinephrine, even though their photophores did not differ at the ultrastructural level from those of the luminous California variety. Professor J. A. C. Nicol (personal communication to F. I. T.) has observed that Porichthys collected near Friday Harbor Marine Laboratory are also non-luminous when injected with epinephrine. In luminescent Porichthys, light is emitted following a luciferase-catalysed oxidation of luciferin by molecular oxygen^12,13. Since Porichthys luciferin and luciferase reciprocally cross react to give light with the luciferin and luciferase of the small marine ostracod crustacean Cypridina^12,13, the possibility that Porichthys might obtain elements of its luminescent system from its diet¹³ has been investigated.