SPECIES OF OCEANIC DINOFLAGELLATES IN THE GENERA <i>DISSODINIUM</i> AND <i>PYROCYSTIS</i>: INTERCLONAL AND INTERSPECIFIC COMPARISONS OF THE COLOR AND PHOTON YIELD OF BIOLUMINESCENCE¹

Abstract

SUMMARY We have examined aspects of the bioluminescence of 5 clones of Dissodinium, 1 clone of Pyrocystis acuta, 4 clones of Pyrocystis fusiformis, and 5 clones of Pyrocystis noctiluca. All clones produced the same color bioluminescence with an intensity peak near 474 nm. The in vivo emission spectra of these clones agreed with those previously determined, for 4 other species of marine dinoflagellates. The amount of light emitted by the dinoflagellates in scotophase when mechanically stimulated to exhaustion was determined for most of the clones. The largest species, P. noctiluca and P. fusiformis, emitted 37–89 × 10 9 photons cell −1 and 23–62 × 10 9 photons cell −1 , respectively, about a thousand, times as much light as Gonyaulax species. Pyrocystis acuta emitted 3–6 × 10 9 photons cell −1 . Three of the 5 clones of Dissodinium were bioluminescent. The range for 3 clones was 5–13 × 10 9 photons cell −1 . All 5 clones of Dissodinium are morphologically distinct. Both the clones of Dissodinium and Pyrocystis produced much higher numbers of photons per cell nitrogen (ca. 7–50 times) than Gonyaulax polyedra or Pyrodinium bahamense. The data suggested that enzyme turnover occurred in the reactions producing light during mechanical stimulation of Dissodinium and Pyrocystis species.