Transcript The effect of depressants on the heart rate of Lumbriculus

The effect of depressants on the heart rate of Lumbriculus variegatus
By:
Zachary Beecher
Brendan Beecher
Introduction:
Lumbriculus variegatus, better known as a
black worm, is a unique creature. They are
used for pulse rate testing because they
have transparent skin which allows one to
easily observe it’s closed-circulatory system.
Black worms are commonly found in
shallow bodies of water such as marshes,
ponds, or lakes. This experiment is testing
the effects of depressants on the worm’s
pulse rate. Our group made the hypothesis
that if a worm lives in depressant water,
then it will have a slower pulse rate than a
worm living in plain spring water.
Trial
Plain
Depressed
1
24
13
2
17
11
3
20
14
4
19
17
5
23
19
Methodology:
Get 5 worms from the plain and
depressant water. Place them in the well
slides with water. View them one at a time
with the microscope, observe and record
the pulse rate of all worms. Draw a
conclusion to prove or disprove the
hypothesis. Place the worm in a cup with
water and then return the water.
Results:
We found that the difference
between the mean of both the
plain spring water and of the
depressant
water
is
5.8.
30
25
20
15
10
5
Plain
WaterDepresse…
0
Materials: Well slides, spring water,
depressant water, stimulant water,
blackworms, microscope, cover slips.
Trial 1
Trial 2
Trial 3
Trial 4
Trial 5
Mean
Median
Discussion:
We can conclude that the
depressants in the water do, in
fact, decrease the pulse rate of
each worm. The blackworms in
the depressant water have a
slower heart rate than the ones
in plain water. The depressants
in the water slow down the
pulse rate of blackworms. Our
results support our hypothesis.