Specimens of Porichthys notatus, which are naturally luminous along the coast of California, are non-luminous in Puget Sound. However, luminescence capability may be induced in the adult Puget Sound Porichthys by the administration of purified Cypridina (ostracod) luciferin, synthetic Cypridina luciferin, or Cypridina organisms. The bioluminescence emission spectra produced by the Puget Sound fish following induction is similar, if not identical, to that of the naturally luminous Porichthys notatus from California waters (maxima: 485 and 507 nm).