First published online June 29, 2006
Journal of Experimental Biology 209, 2704-2712 (2006)
Published by The Company of Biologists 2006
doi: 10.1242/jeb.02289
Metabolic and neuroendocrine effects on diurnal urea excretion in the mangrove killifish Rivulus marmoratus
Tammy M. Rodela and
Patricia A. Wright*
Department of Integrative Biology, University of Guelph, Guelph, ON,
N1G 2W1, Canada

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Fig. 1. Urea tissue levels in whole body R. marmoratus measured every 3 h
over a 1.5-day period (Series I). White and black bars above the graph
indicate periods of light and dark, respectively. Values are expressed as
means + s.e.m. (N=6). Columns labeled with different letters are
significantly different (P<0.05). The broken line represents the
Jurea pattern under corresponding 12 h:12 h L:D conditions
(Rodela and Wright, 2006 ). The
mesor of Jurea is 0.175±0.016 µmol N
g-1 h-1 and the acrophase occurs at 14:30±00:39
h.
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Fig. 2. Diurnal oxygen consumption rates in R. marmoratus over a 3-day
period measured every 6 h for 1 h. White and black bars above the graph
indicate periods of light and dark, respectively (Series II). Values are
expressed as means + s.e.m. (N=12). Oxygen consumption values
followed a significant rhythm (F2,9=15.5,
P=0.0012). The mesor of oxygen consumption is 14.79±6.59
µmol O2 g-1 h-1 and the acrophase is
13:48±00:34 h.
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Fig. 3. Oxygen consumption rates (solid circles) for R. marmoratus
measured for 1 h intervals over a 6 h period (Series III). The white bar above
the graph indicates constant light. Values are expressed as means + s.e.m.
(N=12). Columns labeled with different lowercase letters are
significantly different (P<0.05). Jurea (grey
bars) for R. marmoratus measured for 1 h intervals over a 6 h period
(Series IV). Values are expressed as means + s.e.m. (N=8). Columns
labeled with different uppercase letters are significantly different
(P<0.05).
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Fig. 4. The effect of a single 6 h exposure to 30 µmol l-1 ketanserin
(A) and 1 µmol l-1 RU-486 (B) on Jurea in
R. marmoratus (Series VI). Values are expressed as means ±
s.e.m. (N=8). The arrows indicates the time at which the single dose
of the drug was administered. Treatment values (dotted lines) labeled with an
asterisk are significantly different from control values (solid lines) at
corresponding time intervals (P<0.05). White and black bars above
the graph indicate periods of light and dark, respectively.
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Fig. 5. The effect of 30 µmol l-1 ketanserin on the diurnal cycle of
Jurea in R. marmoratus (Series VII). For
each 6 h time interval following the first exposure to ketanserin (12:00-18:00
h), fresh 30 µmol l-1 solutions were added to the chamber. White
and black bars above the graph indicate periods of light and dark,
respectively. Values are expressed as means + s.e.m. (N=8). Treatment
values (white bars) labeled with an asterisk are significantly different from
control values (black bars) at corresponding time intervals
(P<0.05).
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Fig. 6. The effect of 1 µmol l-1 RU-486 on the diurnal cycle of
Jurea in R. marmoratus (Series VII). For each 6 h
time interval following the initial exposure to RU-486 (12:00-18:00 h), fresh
1 µmol l-1 solutions were added to the chamber. White and black
bars above the graph indicate periods of light and dark, respectively. Values
are expressed as means + s.e.m. (N=8). Treatment values (white bars)
labeled with an asterisk are significantly different from control values
(black bars) at corresponding time intervals (P<0.05).
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© The Company of Biologists Ltd 2006