First published online April 23, 2004
Journal of Experimental Biology 207, 1941-1951 (2004)
Published by The Company of Biologists 2004
doi: 10.1242/jeb.00973
Hydrodynamic stimulation of dinoflagellate bioluminescence: a computational and experimental study
Michael I. Latz1,*,
Andrew R. Juhl1,
,
Abdel M. Ahmed2,
Said E. Elghobashi2 and
Jim Rohr1,3
1 Scripps Institution of Oceanography, University of California San Diego,
9500 Gilman Drive, La Jolla, CA 92093-0202, USA
2 Mechanical and Aerospace Engineering Department, University of California,
Irvine, CA 92697, USA
3 SSC San Diego, 53560 Hull Street, D363, San Diego, CA 92152,
USA
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Fig. 1. Imaging of luminescent response of cells of Lingulodinium
polyedrum for Re=5100. A composite of several video frames shows
responses for five cells superimposed on a view of the nozzle. Each streak
represents the trajectory of a single flash response.
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Fig. 2. Map of the nozzle flow field for numerical simulations at Re=5100
showing color contours of fluid shear stress (left half) and acceleration
(right half).
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Fig. 3. Downstream position of flash initiation (X1) by
Lingulodinium polyedrum (filled symbols) and Ceratocorys
horrida (open symbols) as a function of Reynolds number of the flow.
Symbols represent median values with minimum and maximum range for
approximately 40 cells at each flow. C. horrida responded at lower
flow rates, and flashes were typically located further upstream than for
L. polyedrum.
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Fig. 4. Flow conditions, based on numerical simulations, at the position
(X0, Y0) of stimulated cells of
Lingulodinium polyedrum for cell suspension experiments. Each point
represents the results for a single cell; approximately 40 cells were analyzed
for each flow rate. Filled symbols are for Re=800 while open symbols
are for Re=5100. (A) Position of stimulated cells. Curved line
represents the position of the wall. (B) Fluid acceleration. The broken line
represents a value of zero acceleration. (C) Fluid shear stress.
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Fig. 5. Flow conditions, based on numerical simulations, at the position
(X0, Y0) of stimulated cells of
Ceratocorys horrida for cell suspension experiments. Filled symbols
are for Re=400 while open symbols are for Re=5100. (A)
Position of stimulated cells. Curved line represents the position of the wall.
(B) Fluid acceleration. The broken line represents a value of zero
acceleration. (C) Fluid shear stress.
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Fig. 6. Relative fluid shear stress and acceleration at the position
(X0, Y0) of stimulated cells of
Lingulodinium polyedrum (closed symbols) and Ceratocorys
horrida (open symbols). Relative values were calculated as the ratio of
the flow parameter at the position of a stimulated cell to the maximum value
of that parameter for any Y at that downstream
(X0) position in the flow field. Boxes and circles are for
relative shear stress and acceleration, respectively. Values represent means
± S.E.M. for approximately 40 cells at each flow
condition.
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Fig. 7. Response of cells of Lingulodinium polyedrum injected at the
nozzle inlet at various radial positions for Re=2500. A radial
injection position of 1 is at the inlet wall (=Yin) while
a value of zero is at centerline. Symbols represent mean values ±
S.D. (A) Proportion of cells responding, based on approximately 7
cells injected s-1; cells injected at
<0.6Yin did not respond. All stimulated cells were
located downstream within the thin wall boundary layer. (B) Relative fluid
shear stress and acceleration at the position of stimulated cells
(X0, Y0).
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© The Company of Biologists Ltd 2004
