The present study utilized the dinoflagellates Pyrocystis noctiluca Murray ex
Haeckel and L. polyedrum. Differences exist between these species in regards to several
parameters of bioluminescence. Pyrocystis noctiluca is a large (200 to >350 μm)
unarmored photosynthetic cell that is one of the brightest of all bioluminescent dinoflagellates,
emitting 3.7 × 1010 to 6.5 × 1011 photons cell−1 (Swift et al. 1973, Widder
et al. 1993). Lingulodinium polyedrum is a small (20–30 μm) armored photosynthetic
cell that emits light at approximately the same wavelength as P. noctiluca [472–474
nm (Widder et al. 1983)], but is >1000 times dimmer, emitting between 3.1 × 107 and
1.2 × 108 photons cell−1 (Seliger et al. 1969, Swift et al. 1973, Widder et al. 1993). Also
noteworthy in comparing the luminescent capacity of these two dinoflagellates is
that, under the same conditions, P. noctiluca flashes 10 or more times in response
to prolonged mechanical stimulation while L. polyedrum generally flashes only once
(Widder et al. 1993).