The nature of the bioluminescence of Gonyaulax catenella is
similar to that observed for other dinoflagellates in culture, showing
photoperiod-entrained rhythms of luminescence and stimulability
with relatively constant luminescent capacity during scotophase. G.
catenella is very sensitive to stimulation and photoinbibition. The
nature of the response to stimulation by bubbling appears similar to
that of G. polyedra, and comparisons of the total stimulable light with
G. polyedra indicate that G. catenella emits approximately 6 x 10⁷
photons per cell, during exhaustive scotoptic stimulation.
Over a range of cell concentrations, the rates of cell removal
and filtration for Calanus pacificus when grazed on G. catenella were
considerably lower when the dinoflagellates were in a relatively non-luminescent
phase as opposed to a highly sensitive and luminescent
phase. These differences could not be attributed to differences in
particle size, culture age, distribution of dinoflagellates, ambient
light intensity, rhythms in copepod feeding activity, or other factors
reported to affect copepod grazing. Possible mechanisms of the
effect are discussed.
It is proposed that bioluminescence in dinoflagellates serves
as a protean display type of defense mechanism against copepod
grazing, has selective value, and is of adaptive and ecological significance.
Repository Record Id:
Curl, Herbert C. Jr
Oregon State University. Graduate School
Ecological significance of dinoflagellate bioluminescence