Saddleback Journal of Biology - Saddleback College

Spring 2010 Biology 3B Paper
Effect of pH on vinegar eel (Turbatrix aceti)
Sophia Iribarren
Department of Biological Sciences
Saddleback College
Mission Viejo, California 92692
Turbatrix aceti can tolerate a pH range of 1.6 to 11 for various periods of time. The
objective of this experiment was to test the forward velocity as the pH on the external
medium of T.aceti was changed. The forward velocity was expected to decrease in more
basic and acidic mediums compared to the control group. T.aceti nematodes were placed in
six 30 ml beakers with of solutions at pH of two, four, six, eight, and ten. To determine the
forward velocity ten vinegar eels were timed with a stop watch and distance traveled was
measured through the microscope for each solution. Based on the results obtained, pH did
affect the locomotion of T.aceti in the five experimental groups in comparison to the control
group. 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).These results indicate that pH does affect the
locomotion of T .aceti (p=0.001). One reason for this may be that their naturally
functioning enzymes and ions involved in locomotion do not function well with pH change.
Introduction
The vinegar eel (Turbatrix aceti) is free
living nematode that has been fascinating to many
naturalists. They are a few millimeters in length and
are barely visible to the naked eye. In 1765 Linnaeus
included the Vinegar eel in his Systema Naturae and
named it Chaos redivivum (Peters, 1928). During the
18 th century there was a controversy on the name
given by Linnaeus; he had given the same name to
the worms found in vinegar and the worms found in
book binder’s paste. This issue remained unresolved
until DeMann published a paper on vinegar eels in
1910. The vinegar eel received its new name
Turbatrix aceti (MacGowan, 1982).
T. aceti tolerates a pH range of 1.6 to 11 for
various periods of time and grows in a pH ranging
from 3.5 to 9 (Goodey, 1963). The eelworm can be
recognized by its lack of circular muscles and by its
rapid lateral lashing movement (Galen, 1971). They
move by muscle contraction producing wave like
functions and undulations (Gray, 1939).Vinegar eels
are sinusoidal swimmers (Drewes et. al, 2002).
Nematodes can sense variations in their external
surroundings and respond to them. Muscles of the
body wall are controlled by inhibitory and excitatory
neuromuscular synapses (Alexander, 2002).
The objective of this experiment was to test
the forward velocity as the pH in the medium of
T.aceti was changed. The purpose is to understand
the movement of the muscles and how locomotion is
affected by changes in the concentration of H + ions.
In this study the forward velocity of T. aceti is
expected to decrease in more basic and acidic
mediums compared to the control group.
Materials and Methods
Vinegar eels used in this experiment were
obtained from Wards Biological Society in San Luis
Obispo, CA. Randomly chosen T. aceti were placed
in six 30 ml beakers with solutions at pH of two,
four, six, eight, and ten. The solutions were made
using 1M sodium hydroxide, 0.01M sodium
hydroxide, 1M hydrochloric acid, and 0.01 M
hydrochloric acid. A solution with a pH of three was
used as the control group since the optimum pH level
of T.aceti is three (Ells et al., 1961). The vinegar eels
were allowed to get acclimated to the different pH
levels for 24 hours at room temperature.
After the acclimation period, a sample of
vinegar eels was placed under the E2000 microscope
at low power (4x). Ten vinegar eels were timed with
a stop watch and the distance traveled was measured
through the microscope for each solution. The head
of the vinegar eel was used as the start and finish
reference point. By determining the traveled distance
and time elapsed, the forward velocity was
determined.
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Saddleback Journal of Biology
Spring 2010