1. Quan%fying
the
schooling
behavior
of
Pimephales
promelas
when
exposed
to
a
predatory
s%mulus
Victoria Arling, Dana Calhoun, Pieter Johnson
Methods
§ Six
fathead
minnows
were
collected
and
placed
in
a
2.5
gallon
tank.
They
were
allowed
to
acclimate
for
5
minutes
and
then
10
trials
were
carried
out
to
track
and
quan?fy
their
schooling
behavior
as
a
response
to
a
predatory
s?mulus.
§ The
minnows
schooling
spread
area
was
calculated
before,
during,
and
aCer
the
introduced
predator;
their
reac?on
?me
to
forming
a
school
was
also
measured.
The
fish
were
alloFed
a
2
minute
recovery
?me
between
each
trial.
Abstract
Fish
schooling
is
an
evolu?onary
mechanism
for
predator
avoidance.
My
project
aimed
to
observe
and
quan?fy
the
schooling
behavior
of
fathead
minnows
(Pimephales
promelas)
when
exposed
to
a
predatory
s?mulus.
The
fathead
minnow’s
schooling
size
and
reac?on
?mes
were
measured
before,
during,
and
aCer
a
predatory
s?mulus
(ping
pong
ball)
was
introduced,
which
allowed
me
to
track
the
changes
in
their
schooling
behavior.
The
results
demonstrated
that
there
is
general
decline
in
the
minnow’s
schooling
size
aCer
the
predator
is
introduced,
emphasizing
that
the
minnows
are
schooling
together
in
?ght
forma?ons
as
a
predatory
avoidance
behavior.
Future Study
This
study
has
provided
baseline
data
on
the
schooling
behavior
of
fathead
minnows
when
exposed
to
a
predatory
s?mulus.
Next,
I
plan
to
infect
the
fathead
minnows
with
R.
ondatrae
and
use
that
data
to
test
and
quan?fy
their
schooling
behavior
aCer
parasi?c
infec?on.
This
will
allow
for
a
crosswise
comparison
of
my
data
between
non-­‐infected
and
infected
trials.
This
study
will
provide
valuable
insight
to
the
parasitology
community
by
showing
how
R.
ondatrae
directly
affects
the
fathead
minnows
schooling
behavior,
in
order
for
the
parasite
to
complete
it’s
life
cycle.
Results
Discussion
My
study
showed
that
fathead
minnows
form
rela?vely
?ght
schools,
as
a
defense
mechanism,
when
exposed
to
a
predator.
As
seen
in
Figure
1,
the
fathead
minnows
schooling
are
was
largest
before,
smallest
during,
and
mid-­‐sized
aCer
the
predator
was
introduced.
Figure
2
(leC)
shows
that
the
fathead
minnow’s
schooling
size
was
greatly
reduced
aCer
the
predatory
s?mulus
was
introduced.
Also
longer
reac?on
?mes
to
forming
a
school
corresponded
to
a
larger
reduc?on
in
area
(right).
These
results
suggest
that
minnows
tend
to
school
in
?ght
forma?ons
as
a
predatory
avoidance
behavior,
which
is
also
shown
in
the
results
found
in
Hager
et
al.,
1991.
References
Hager,
M.
C.,
&
Helfman,
G.
S.
(1991).
Safety
in
numbers:
shoal
size
choice
by
minnows
under
predatory
threat.
Behavioral
Ecology
and
Sociobiology,
29(4),
271–276.
Johnson,
P.
T.
J.,
&
Paull,
S.
H.
(2011).
The
ecology
and
emergence
of
diseases
in
fresh
waters:
Freshwater
diseases.
Freshwater
Biology,
56(4),
638–657.
doi:10.1111/j.1365-­‐2427.2010.02546.x
Johnson,
P.
T.,
&
Lunde,
K.
B.
(2005).
Parasite
infec?on
and
limb
malforma?ons:
a
growing
problem
in
amphibian
conserva?on.
Amphibian
Declines:
The
ConservaFon
Status
of
United
States
Species.
University
of
California
Press,
Berkeley,
124–138.
Department of Ecology and Evolutionary Biology, University of Colorado at Boulder
Introduction & Background
Previous
studies
in
freshwater
environments
show
that
parasites
can
have
adverse
effects
on
fish,
increasing
the
fish’s
suscep?bility
to
preda?on,
in
order
for
the
parasite
to
complete
it’s
life
cycle.
Research
in
the
Johnson
Laboratory
has
confirmed
that
Ribeiroia
ondatrae
metacercaria
(a
freshwater
trematode
parasite)
have
been
found
to
encyst
in
various
body
loca?ons
in
species
of
freshwater
fish
including
the
eye-­‐lids,
stomach,
and
the
lateral
line
(Johnson
et
al.,
2001).
However,
currently
liFle
is
known
if
R.
ondatrae,
manipulates
the
behavior
of
freshwater
fish,
specifically
fathead
minnows.
Schooling
is
one
known
useful
defense
mechanism
displayed
by
fish
(Hager,
et
al.,
1991).
My
study
aimed
to
collect
baseline
data
on
schooling
behavior
of
fathead
minnows
when
exposed
to
a
predatory
s?mulus.
This
baseline
data
will
allow
for
future
inves?ga?ons
in
how
R.
ondatrae
affects
the
schooling
behavior
of
fathead
minnows.
Acknowledgements
§ Thank
you
to
the
Undergraduate
Research
Opportuni?es
Program
Howard
Hughes
Medical
Ins?tute
for
funding
my
research.
§ Thank
you
to
Dana
Calhoun
and
other
members
of
the
Johnson
Laboratory
personnel
for
all
of
your
contribu?ons
and
assistance
with
running
my
experiment
and
analyzing
my
data.
§ Thank
you
to
Dr.
Pieter
Johnson
and
the
Johnson
Laboratory
for
this
research
opportunity
and
support
for
my
project.
0
100
200
300
400
500
pre peri post
Time point
Area
Figure
1:
Fathead
minnow’s
schooling
size
before,
during,
and
a@er
predatory
s%mulus.
0 100 200 300 400 500
2468
area
Reactiontime
initial area
area after stimulus
100
200
300
400
500
2.5 5.0 7.5
Reaction time
Reductioninarea
Figure
2:
Fathead
minnow’s
schooling
area
reduc%on
as
a
func%on
of
reac%on
%me.
LeC:
Ribeiroia
ondatrae
metacercaria
Right:
Ribeiroia
ondatrae
metacercaria
encysted
in
the
lateral
line
of
a
fish’s
scales.
(cm2)
(sec)
(cm2)
(sec)
(cm2)