Saddleback Journal of Biology - Saddleback College

Spring 2010 Biology 3B Paper
The forward velocity (V F ) of the vinegar eel was
measured using the following formula:
change in distance(mm·s-1)
VF =
change in time(s)
This same procedure was repeated with all of the six
solutions.
Results
Sixty vinegar eels were used in this
experiment. Results indicate (Figure 1) that the
average forward velocity of T.aceti after acclimated
in the five different pH solutions was significantly
different (ANOVA, p= 0.001). The control group
demonstrated a significantly higher V F on average
than the experimental groups. As the pH of the
solution was increased or decreased, the average V F
of T.aceti lowered over the measured period. The
mean V F for pH 2 was 10.7 ± 1.43 mm · s -1 (±SEM,
N=10), for pH 3 was 16.8 ± 5.61 mm · s -1 (±SEM,
N=10), for pH 4 was 11.0 ± 2.36 mm· s -1 (±SEM,
N=10), pH 6 was 9.24 ± 1.98 mm · s -1 (±SEM,
N=10), pH 8 was 9.23 ± 1.66 mm · s -1 (±SEM,
N=10), and for pH 10 was 4.84 ± 2.70 mm · s -1
(±SEM, N=10). A Bonferroni correction was run and
the results showed significance between pH: 2 and 3,
2 and 10, 3 and 4, 3 and 6, 3 and 8, 3 and 10, and 4
and 10.
16
Forward velocity (mm · s -1 )
14
12
10
8
6
4
2
0
0 2 4 6 8 10 12
pH
Figure 1. Average forward velocity (mm·s -1 ) of T.aceti after being acclimated in different pH. ANOVA showed a
significant difference (p=0.001).
Discussion
T. aceti locomotion was affected with the
change in pH. The effect on locomotion was shown
by the decrease of the forward velocity. T. aceti, in
more acidic and basic medium was not able to
maintain the same velocity when compared to the
control group. This confirms that the vinegar eel’s
optimum pH is three; however they also have the
ability to tolerate abrupt pH changes ranging from
three to ten.
There may be some reasons why the V F of
T. aceti was affected. The naturally functioning
enzymes and ions involved in locomotion do not
function well with changes in pH. In nematodes
locomotion depends on transmission forces generated
by muscular contractions (Gaugler et al., 2004).
Enzymes have an optimum pH at which their
activity is maximal, as the pH increases or
decreases the enzymatic activity can be altered
leading to a change in other metabolic functions
(Lehringer et al., 2005). Ion imbalance could
have affected their locomotion. In acid-stressed
fish populations an ionic imbalance is the
physiological mechanism responsible for fish
depletion (Jones, 1985).
Another reason why the V F of T. aceti
was affected could have been from the stress of
pH change. This stress could have altered their
balance and coordination forcing them to swim
at a slower speed. In studies done by Jones et
al. (1985) fish that were placed in acidic
mediums presented it difficult and strenuous to
swim; normal activities such as eating were no
longer a priority. Since a gradual pH acclimation
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Saddleback Journal of Biology
Spring 2010