spencer cushen, lindsey graham, steven bull, baylor university
TRANSCRIPT
Spencer Cushen, Lindsey Graham, Steven Bull, Baylor University, Waco Texas, 76798
Abstract: The objective of the experiment was to examine the overall effects of Fluoride pollution
on reproduction rates of Simocephalus serrulatus. The hypothesis was if S. serrulatus
exposed to 251 mg/L there would be a significant reduction in reproduction. Small
populations of S. serrulatus were maintained in controlled conditions each submerged in
solutions of varying concentrations of sodium fluoride. The general trend showed that as
the concentration of sodium fluoride increased the reproduction rate decreased.
Introduction: Sodium Fluoride is a common constituent in
everyday products including toothpaste,
medications and drinking water. When
experienced in high concentrations Fluoride
ions can be toxic to humans and other
organisms (Anderson, 1946).The hypothesis
was the higher levels of sodium fluoride will
cause a change in reproductive behavior.
Methods and Materials: • 12 containers (1L) were set up as 3
variables and 1 control with 3 trials each.
• The control group contained Lake Waco
Wetlands water filtered with a 120 micron
mesh filter to remove zooplankton; as were
the experimental groups A,B and C with
added concentrations of (100, 158 and
251mg NaF/L respectively). These
concentrations were based off the values
used in Fiesers’ experiment.
• The test was conducted over 3 weeks on a
12-12 light cycle at room temperature. The
first week was to allow the 10 S. serrulatus
per container to mature and become
reproductively active. Counts of overall
organisms were conducted both of the
following weeks. The babies were removed
and the 10 adults were returned to the
containers.
Conclusion & Discussion: Due to the common dispersal of Sodium Fluoride in water the effects
this pollutant has on S. serrulatus could have a correlation to toxicity in
humans when exposed in high concentrations. In comparison to the
findings of Fieser et al the results were similar however we performed a
field type experiment instead of the sterile technique type where
filtered wetlands water was used instead of double distilled water with
nutrients added. Although a different species this contributes to the
credibility of their findings by corroborating the reproduction numbers
seen in their Daphnia magna cultures by the reproduction numbers of
S. serrulatus (Fieser et al, 1986). Measuring the effect of sodium
fluoride on S.serrulatus allows for a better understanding of the way
pollutants released as byproducts of industrial activity makes an
impact on local ecosystems.
Acknowledgments: A special thanks to Dr. Marty Harvill; Nora Schell, Lake Waco
Wetlands coordinator and Baoqing Ding.
Literature cited : Anderson, B. G. (1946). The toxicity Thresholds of Various Sodium Salts Determined by
the Use of Daphnia Magna. Sewage Works Journal, 82-87.
Fieser, A. H., Sykora, J. L., Kostalos, M. S., Wu, Y. C., & Weyel, D. W. (1986). Effect of
Flouride on Survival and Reproduction of Daphnia Magna. Journal (Water Pollution
Control Federation), 58(1), 82-86.
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Control 100mg/L 158mg/L 251mg/L
Co
un
t o
f S
.se
rru
latu
s
Concentration of Sodium Fluoride
S.serralutus reproduction count over a one week interval in
varying concentrations of Sodium Fluoride
Figure 2
Figure 1
Figure 3