Susceptibility of common carp fry (Cyprinus carpio L.) to infection by gill and muscle Myxosporea


Maskur, D.D.

Biotropia 3: 62-66

1989


Three species of Myxosporea (Myxobolus koi, M. toyamai, and Thelohanellus callisporis) were found in the gills, and 2 species (T. callisporis and Myxosoma sp.), were found in the muscles of common carp in Indonesia. T. callisporis could infect the fry as early as 2 days after hatching, whereas Myxobolus koi, M. toyamai, and Myxosoma sp. infected older fry, around 6-8 days after hatching. The mature spores of T. callisporis were found 21 days pi whereas those of M. koi, M. toyamai, and Myxosoma sp. were found 41, 23 and 55 days pi respectively. The control of these parasites is discussed in the light of these findings.

BIOTROPIA
No.
3,
1989/1990:
62
66
SUSCEPTIBILITY
OF
COMMON
CARP
FRY
(CYPRINUS
CARPIO
L.)
TO
INFECTION
BY
GILL
AND
MUSCLE
MYXOSPOREA
MASKUR
Fresh
Water
Aquaculture
Development
Center,
Sukabumi,
Indonesia
DARNAS
DANA
Bogor
Agricultural
University,
Bogor, Indonesia
ABSTRACT
Three
species
of
Myxosporea,
Myxobolus
koi,
M.
toyamai,
and
Thelohanellus
callisporis,
were
found
in
the
gills,
and
two
species
Thelohanellus
callisporis
and
Myxosoma
sp.
were
found
in
the
muscles
of
common
carp
in
Indonesia.
Lack
of
knowledge
of
the
biology
of
these
parasites,
especially
of
the
Indonesian
species,
makes
it
difficult
to
prevent
infections
of
aquaculture
systems.
This
problem
is
aggravated
by
the
transfer
of
seed
(susceptible
fish)
between
localities,
which
is
a
common
practice
to
extend
the
production
system
in
Indonesia.
It
is
shown
that
Thelohanellus
callisporis
could
infect
the
common
carp,
the
fries,
as
early
as
2
days
after
hatching,
whereas
Myxobolus
koi,
M.
toyamai,
and
Myxosoma
sp.
infect
older
fries,
around
6
8
days
after
hatching.
The
mature
spores
of
Thelohanellus
callisporis
were
found
21
days
post-infection,
whereas
those
of
Myxobolus
koi,
M.
toyamai,
and
Myxosoma
sp.
were
found
41,
23
and
55
days
post-
infection,
respectively.
The
significance
of
the
findings
is
discussed
in
relation
with
establishing
proper
control
methods
of
these
parasites.
One
important factor
is
the
age
of
fries
or
fingerlings
to
be
transferred.
More
than
44-day
old
fries
or
fingerlings
are
believed
to
be
free
of
the
parasites.
INTRODUCTION
The
emphasis
of
freshwater
fish
culture
development
in
Indonesia
is
still
placed
on
common
carp
(Cyprinus
carpio).
This
is
due
to
the
high
demand
and
the
high
(commercial)
value
(US$
2/kg)
of
this
species.
But
more
importantly,
the
culture
technique
of
common
carp
is
well
established.
Disease
is
one
of
the
most
serious
limiting
factors
in
aquaculture.
This
is
especially
true
in
unnaturally
high
population
density
which
is
a
common
practice.
In
addition,
the
transfer
of
this
species
from
one
place
to
another
is
a
vital
daily
activity
to
extend
the
production
system
throughout
the
country
(Indonesia).
Such
conditions
favour
the
spread
of
disease
and
parasites.
One
of
the
important
parasites
that
limit
the
production
of
common
carp,
especially
during
fry
and
fingerling
stages
62
Susceptibility
of
common
carp
fry
(Cyprinus
carpio
L.)—Maskur
&
D.
Dana
in
Indonesia,
is
the
Myxosporean
group.
According
to
Rukyani
(1978),
mortality
could
reach
99
0
7o
in
a
massive
infection.
The
outbreak
of
myxosporeasis
in
Indonesia
could
be
traced
back
to
as
early
as
1935
(Sachlan
1952).
Billions
of
fries
were
killed
due
to
Myxobolus
pyriformis
infection,
although
the
affected
species
was
not
common
carp.
In
spite
of
the
de-
vastating
effects
of
this
parasite,
little
is
known
about
the
biology
of
the
organism.
This
paper
reports
the
earliest
susceptible
age
of
common
carp
to
gill
and
muscle
Myxosporea.
By
doing
this,
it
is
hoped
that
the
spread
of
this
pathogen
can
be
limited
through
transportation
strategy,
taking
into
consideration
that
no
effective
control
measures
for
this
parasite
is
yet
established.
MATERIALS
AND
METHODS
Eggs
of
common
carp
were
obtained
from
one
female
brood
stock
spawned
in
concrete
pond
supplied
with
spore-free
spring
water.
One
hundred
eggs
from
this
lot
were
taken
for
spore
contamination
examination.
The
spore-free
eggs
were
hatched
in
transmission
ponds
with
high
natural
myxosporean
infection.
The
transmission
pond
was
supplied
with
regular
irrigation
water.
To
pre-
vent
the
experimental
fish
going
out
and
the
wild
fish
coming,
the
inlet
and
the
outlet
were
provided
with
wire
screen
layered
with
linen.
The
pond
was
fertilized
with
chicken
manure
at
the
rate
of
500
g/m
2
.
Several
periods
after
hatching
(2,
4,
6,
8,
12,
16,
20, 24,
28,
32, 36,
40,
and
44
days),
a
batch
of
150
fish
was
taken
for
each
period
from
the
transmission
pond.
They
were
placed
in
separate
(13)
plastic
containers
and
supplied
with
spore-free
spring
water.
The
fishes
were
fed
with
young
Daphnia
and
crumbled
artificial
feed.
Examination
for
Myxosporea
infection
was
conducted
at
weekly
intervals
for
nine
weeks
beginning
at
the
first
week
after
the
fishes
were
kept
in
the
plastic
con-
tainers.
Two
fishes
were
examined
at
each
interval.
The
gills
were
scraped
and
the
flesh
were
ground
for
spore
detection.
Examination
of
the
eggs
and
the
fish
was
conducted
with
the
use
of
an
Olympus
stereo
microscope.
For
the
spores,
observation
and
measurements
were
conducted
under
ophtiphot
phase
contrast
Nikon
compound
microscope.
63
BIOTROPIA
No.
3,
1989/1990
RESULTS
AND
DISCUSSION
Identification
of
spores
The
description
of
Myxosporea
is
usually
based
on
the
morphological
charac-
teristics
of
their
vegetative
stages
and
spores.
In
many
instances,
especially
among
histozoic
forms,
species
have
been
described
on
the
basis
of
spores
alone.
Based
on
spore
characteristics,
three
species
of
Myxosporea,
Myxobolus
koi,
M.
toyamai,
and
Thelohanellus
callisporis,
were
found
in
the
gills,
and
two
species
of
Myxosporea,
Thelohanellus
callisporis
and
Myxosoma
sp.
were
found
in
the
muscles
of
common
carp.
The
species
and
spore
measurements
are
presented
in
Table
1.
The
results
are
in
close
agreement
with
those
reported
by
Kudo
(1917)
for
Myxobolus
toyamai,
by
Ha
Ky
(1971)
for
Thelohanellus
callisporis,
and
by
Pav-
lovskii
(1962)
for
the
others.
Myxobolus
toyamai
and
Thelohanellus
callisporis
were
new
species
recorded
in
Indonesia.
In
Asia,
these
parasites
were
first
recorded
in
Japan
(Kudo
1917)
and
in
Vietnam
(Ha
Ky
1971).
Table
1.
Measurements
(in
micron)
of
Myxosporea
from
the
gill
and
muscles
of
common
carp
(Cyprinus
carpio).
Number
in
parentheses
indicates
the
spores
examined
Characters
Kind
of
Myxosporea
Myxobolus
koi
Myxobolus
toyamai
Thelohanellus
callisporis
Myxosoma
sp.
Spore
Length
range
average
Width
range
12.5
13.5
6.3
-
15.0
±
0.7
-7.5
(100)
(100)
(100)
13.8
15.1
5.0
-
17.5
±
0.8
-
6.3
(103)
(103)
(103)
18.8
-
25.0
22.3
±
1.2
8.8
-
12.5
(26)
(26)
(26)
7.5
8.0
10.0
-
9.4
±
0.6
-
13.1
(101)
(101)
(101)
average
Thickness
range
6.5
5.0
±
0.5
-
6.3
(100)
(87)
6.1
5.0
±
0.4
-
6.3
(103)
(103)
10.7
±
0.9
8.8
-
10.0
(26)
(11)
12.2
5.6
±
0.7
±
6.9
(101)
(50)
average
Polar
capsule
Length
range
6.0
6.3
±
0.3
-
7.5
(87)
(100)
5.1
6.3
±
0.3
-
10.0
(103)
(103)
9.6
10.0
±
0.4
-
13.8
(11)
(26)
6.3
4.4
±
0.1
-
6.3
(50)
(101)
average
Width
range
7.8
2.5
±
0.6
-
3.8
(100)
(100)
8.3
3.1
±
0.9
-
4.8
(103)
(103)
11.7
7.5
±
0.9
-
10.6
(26)
(26)
5.4
2.5
±
0.6
-
5.0
(101)
(101)
average
2.5
±
0.2
(100)
3.7
±
0.2
(103)
8.5
±
0.9
(26)
3.8
±
0.3
(101)
64
Susceptibility
of
common
carp
fry
(Cyprinus
carpio
L.)
Maskur
&
D.
Dana
Susceptibility
The
earliest
susceptible
age
of
common
carp
to
myxosporean
infection
and
time
scale
development
of
Myxosporea
varied
between
species
(Table
2).
The
table
shows
that
Thelohanellus
callisporis
could
infect
the
common
carp
as
early
as
2
days
after
hatching
whereas
Myxobolus
koi,
M.
toyamai
and
Myxosoma
sp.
infect
older
fry,
around
6
8
days
after
hatching.
However,
no
spore
was
found
from
the
eggs.
Table
2.
Susceptibility
of
common
carp
fry
(Cyprinus
carpio)
to
infection
by
Myxosporea
Parasite
Age
after
hatching
(days)
0
2
4
6
8
12
16
20
24
28
32
36
40
44
Myxobolus
koi
+
+
+ +
+
+ +
Myxobolus
toyamai
+
+
+
+
+ +
+ +
+
Thelohanellus
callisporis
+ +
+
+ + +
+
+ +
+ + +
Myxosoma
sp.
+ +
+
+
+
+
+
+
Note:
(
)
Spores
not
detected
(
+
)
Spores
detected
Observations
on
the
initial
stages
of
Myxosporean
parasites
were
limited.
The
work
revealed
that
the
mature
spores
of
Thelohanellus
callisporis
was
found
21
days
post-infection
whereas
those
of
Myxobolus
koi,
M.
toyamai,
and
Myxosoma
sp.
were
found
41,
23,
and
55
days
post-infection,
respectively.
The
experiment
also
showed
that
44-day
old
fingerlings
were
free
from
the
parasites.
The
fish
culture
activities
rely
on
fish
transfer,
i.e.
of the
fry
or
fingerlings
from
hatcheries
to
rearing
ponds
and
of
the
fish
harvested
from
the
ponds
to
the
markets.
The
most
realistic
option
to
minimize
the
risk
of
disease
spread
is
the
es-
tablishment
of
a
quarantine
system.
In
the
case
of
Myxosporea,
since
the
early
stages
of
this
parasite
are
hardly
detected
and
symptoms
of
the
disease
could
not
be
seen
in
early
infection,
the
fish
quarantine
system
is
important.
From
the
foregoing
facts,
two
options
could
be
taken
as
a
strategy
to
limit
the
risks
of
spreading
Myxosporea.
Firstly,
only
eggs
could
be
transported
between
places,
and
secondly,
the
fingerlings
should
be
older
than
44
days.
ACKNOWLEDGMENTS
The
research
was
partly
supported
by
the
International
Development
Research
Centre
(IDRC)
of
Canada
under
grant
number
3
P
82
0198.
65
BIOTROPIA
No.
3,
1989/1990
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KY
1971.
Some
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of
freshwater
fishes
of
the
North
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Protozoologica
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298.
Kuoo,
R.R.
1917.
Contribution
to
study
of
parasitic
protozoa.
II.
Myxobolus
toyamai
nov.
spec.,
a
new
myxosporidian
parasite
in
Cyprinus
carpio
L.
J.
Parasitol.
3:
163
—170.
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E.N.
(Ed.).
1962.
Key
to
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of
freshwater
fish
of
the
USSR.
(English
transl.,
A
Birron
1964.
Israel
Prog.
Sci.
Transl.
Jerussalem),
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p.
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A.
1978.
Occurrence
of
Myxobolus
koi
(Myxobolidae)
in
cultured
fishes
in
Java,
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The
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on
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Fish
Diseases,
Cisarua,
Bogor,
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p.
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H.
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66