Mediterranean Aquaculture Journal 2008 1(1); 1-9
Original Article
Study on Some Ectoparasitic Diseases of Catfish, Clarias gariepinus with
their Control by Ginger, Zingiber officiale
J F. K. Abo-Esa
Parasitological Unit, Fish Diseases Research Department, Animal Health Research Institute, Egypt
Abstract
Parasitological investigation was performed in one hundred naturally collected Nile catfish Clarias
gariepinus. It revealed skin and gill infestation with ectoparasitic protozoan Trichodina and Epistylis
and monogenean Gyrodactylus spp. with average 20, 15 and 25%, respectively. The average of the total
ectoparasitic infestation in the examined catfish was 60%.The significance of herbal control measures
using ginger Zingiber officiale as a new method to eradicate such parasites, was evaluated. A bioassay
of 96 hours LC of ginger emphasized that its value was 192mg/L. The herbal control with ginger was
50
safe and effective to treat the ectoparasitic protozoa Trichodina and Epistylis spp. at dose 20mg/L, but
not suitable for treating the monogenean Gyrodactylus spp. The estimation of dissolved oxygen, pH
and total ammonia of aquarium water pre and during treatment was indicated that the use of ginger in
aquaculture operation will improve its water quality especially the total ammonia.
Key Words: Clarias gariepinus, Trichodina spp., Epistylis spp., Gyrodactylus spp., Ginger,
Aquaculture.
Received: 30 June 2007
Accepted: 16 October 2007
---------------------------------------------------------------------------------------------------------------------------
Introduction
The African catfish, Clarias gariepinus is
fingerling mortalities, especially in culture
one of the most important fish species for an
system due to the invasion of parasites. The
economically successful aquaculture. However,
protozoan Trichodina spp. and the monogenean
farmers are constraint with massive fry and
Gyrodactylus spp. were the dominant parasites
----------------------------------------------------------------------------------------------------------------------------
Correspondence:
Jihan FathAlla Khalifa Abo-Esa
Parasitological Unit, Fish Diseases Research Department, Animal Health Research Institute,
Dokki, Giza, Egypt. Tel. : +2 0166544331,
E-mail: Dr.Jihan_f@Yahoo.com
Copyright : All rights reserved to Mediterranean Aquaculture and Environment Society (MAES)

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Study on Some Ectoparasitic Diseases of Catfish
which were aggravated pathological effects
gariepinus fish with calculating optimum dose
on fish and increasing mortality (Akoll 2005).
that can completely eradicate these parasites by
Moreover, Kristmundsson et al. (2006) stated
determination of the lethal concentration 50 of
that the rearing environment with a subsequent
ginger and safety margin for such fish.
increase in biomass and decreasing temperature
caused a proliferation of trichodinids. Also,
Materials and Methods
during parasitological surveys in Chogqing,
China, Zhao and Tang (2007) investigated
Parasitological examination of fish:
three trichodinids infesting a freshwater fish
A total of 145 freshwater Clarias gariepinus
and a mollusc. Hubert and Warner (1975)
ranged from 200-250 g body weight were
recorded that Epistylis first appeared on the
collected alive from El-Monib, Giza governorate
tips of both dorsal and pectoral fin spines.
fish market and transported immediately to the
When untreated, Epistylis colonies spread and
lab in large plastic bags partially filled with
eventually covered much of the anterior region
water and containing air according to Langdon
of the body and causes mortality of catfish.
and Jones (2002). The fish were examined for
Paperna (1996) mentioned that fish heavily
gross clinical signs and pathological lesion.
infested with Gyrodactylus appeared pale, due
The necropsy technique of parasitological
to excessive mucus secretion and epithelial
examination of skin, fins and gills was carried
proliferation. In the more heavily infested skin
out for the presence of external parasites with
zones, there are skin erosion, desquamation
recording the average and intensity of the isolated
of the skin epithelium, focal hemorrhagic
parasites from one hundred catfish, the other 45
lesions and severe mortalities. In addition,
catfish were kept for applying the treatment. The
Boeger et al. (2005) reported that viviparous
recovered protozoa and monogenea were fixed,
gyrodactylids exhibit extraordinary species
preserved and stained according to Paperna
diversity and broad host range if compared to
(1996), Langdon and Jones (2002).
other monogenean groups.
Ginger (Zingiber officiale):
In the last few years, the herbal treatments
It was obtained as patent preparation in a Tablet
were developed for replacing the chemical
form from MEPACO. Ginger is belonging to
used for eradication of the most harmful
the Zingiberaceae plant family. Ginger contains
parasites infesting terrestrial animals. In this
several chemical components as outlined by
respect, several herbs were used in pest and
Murray (1995): starch (50%), protein (9%),
parasitic control as ginger which contains over
lipids (including glycerides, phosphatidic
four hundred chemically active ingredients,
acid, lecithins, and fatty acids, 6-8%), protease
has long been used for treatment a variable
(2.26%) and volatile oils (including gingerol,
diseases. It has a wide range of actions against
shogoal, zingiberene and zingiberol, 1-3%). In
parasites (Leo 2001). In addition, Pro (2003)
addition, it contains vitamins A and B3 (niacin)
stated that ginger is the newest homeopathic
treatment to be suggested. Practically, Colorni
Ginger lethal concentration-50 (LC ):
(1987) succeeded to treat fish infected with
50
A total number of 100 fish were divided into
Cryptocaryon irritans with ginger for ten days
ten groups. The fish were exposed to different
with changing water every three days.
concentrations of ginger (Table 2), kept under
observation for 96 hours and numbers of dead
The present study was planned to endeavour
fish were recorded. The results were statistically
of evaluating the possible use of new herbal
analyzed according to Behrens and Karber
control (Ginger) against some ectoparasitic
(1953) by this equation:
protozoa and monogenea that infested Clarias
2
Mediterranean Aquaculture Journal 2008 1(1); 1-9

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Jihan F. K. Abo-Esa
AXB
spp. revealed pale skin and excessive mucus
LC = Largest dose - ?---------------------
secretion. Skin erosion with local hemorrhagic
50
N
lesions was demonstrated in some infested fish
(Fig. 1a&b).
Where A is the mean of dead fish between two
successive doses.
B is dose differences between two successive
doses.
N is the total number of fish.
Efficacy of Ginger bath on the ectoparasites
infesting C. gariepinus:
A total of 45 alive naturally infested C.
gariepinus were divided in three groups of 15
fish each in a volume of water (100x 40x 15
cm, 60 liters) with good aerated conditions. The
safe level of ginger applied to infested fish was
Fig. 1a: Clarias gariepinus showing pale mucus, erosions
the 10 times lower than the value of ginger 96
and ulceration in the skin.
hours LC (Boyd 1998). It was approximately
50
20 mg/L. The fish in the first group was exposed
to 10 mg/L ginger while the second group was
exposed to 20 mg/L ginger and the third group
was considered a control.
The water quality of fish aquarium before
and during treatment:
The fish were kept in the same volume of cleaned
water (60-L for 15 fish) with good aeration and
dechlorinated tap water, for at least one week
before treatment. Water samples from each
aquarium were analyzed at room temperature
before and during treatment for estimating
the dissolved oxygen, pH and total ammonia
(Masser and Jensen 1991). The dissolved
Fig. 1b: Clarias gariepinus showing pale mucus and
oxygen was measured by Cole Parmer 5946-50-
ulcerative as well as erosive skin lesions.
oxygen meter, Analog field kit. The pH of water
was measured by pH meter (Economy pH/mV/
Parasitological examination:
ºC, Benchtop Meter) and the total ammonia was
The parasitological examination revealed single
measured by the colorimeter apparatus (Model
and mixed infestation of some C. gariepinus
6030-operating manual-Janway).
with the ciliated ectoparasites Trichodina
and Epistylis spp. in addition to monogenean
Results
ectoparasites Gyrodactylus spp. (Table 1).
Gross macroscopic examination:
Based on the morphological examination of the
The gross examination of infested fish with the
isolated ectoparasites, they were identified as the
isolated ectoparasitic protozoan, Trichodina,
following:
Epistylis and monogenean Gyrodactylus
Mediterranean Aquaculture Journal 2008 1(1); 1-9
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Study on Some Ectoparasitic Diseases of Catfish
Table 1: Average and intensity of infestation with external parasites infested Clarias gariepinus.
No of Examined
Total infested
Single
Mixed infestation
Intensity of
Parasites
fish
fish %
infestation%
%
infestation
No./ field (10X)
Trichodina spp.
20
8-10
Epistylis spp.
100
60
15
30
15-18
Gyrodactylus spp.
25
6-8
Ectoparasitic protozoa:
•
Phylum: Ciliophora
•
Class: Ciliatea
•
Subclass: Peritricha
•
Order: Mobilina
•
Family: Trichodinidae
•
Genus: Trichodina
•
Species: Trichodina species
Based on the morphological examination of the
isolated ectoparasites, they were identified as the
following:
Ectoparasitic protozoa:
•
Phylum: Ciliophora
•
Class: Ciliatea
•
Subclass: Peritricha
Fig. 2: Trichodina spp. isolated from the skin and of C.
•
Order: Mobilina
gariepinus (Stained with Giemsa´s stain) (X400).
•
Family: Trichodinidae
•
Genus: Trichodina
•
Phylum: Ciliophora
•
Species: Trichodina species
•
Class: Ciliatea
•
Subclass: Peritricha
Trichodina spp. is isolated from skin, fins and
•
Order: Peritrishida
gills of infested C. gariepinus. It is large with disc
•
Suborder: Sessilina
shaped body. The adhesive disc is saucer shaped.
•
Phylum: Ciliophora
The parasite is provided with several rows of
•
Class: Ciliatea
cilia at the circular periphery and the inner circle
•
Subclass: Peritricha
of toothed denticles. The macronucleus is horse
•
Order: Peritrishida
shoe-shaped and micronucleus is small and
•
Suborder: Sessilina
difficult to be seen in some specimens (Fig. 2).
•
Family: Epistylidae
•
Genus: Epistylis
•
Species: Epistylis spp.
Epistylis spp. is isolated from skin and gills of
infested catfish. It is a sessile contractile ciliate.
4
Mediterranean Aquaculture Journal 2008 1(1); 1-9

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Jihan F. K. Abo-Esa
Stalk is long and non contractile. Often forms a
branched colony. The distal end of the organism
is surrounded by rapidly moving cilia which
appear as a blur (Fig. 3).
Fig. 4: Gyrodactylus spp. recovered from the gills of C.
gariepinus (stained with Borax carmine stain) (X50).
Fig. 3: Epistylis spp. recovered from the gills of C. gariepinus
(wetpreparation) (X100).
Ectoparasitic monogenea:
•
Phylum: Platyhelminths
•
Class: Dactylogyroidea
•
Family: Gyrodactylidae
•
Genus: Gyrodactylus
•
Species: Gyrodactylus spp.
The monogenetic Gyrodactylus is detected
in gills and skin of infested C. gariepinus. It
is flat worm with one pair of projection at its
anterior pole. It can be distinguished from other
Fig. 5: Morphology and structure of recovered Gyrodactylus
monogeneans by the absence of eye spots and
spp (stained with Borax carmine stain).
the occurrence of the embryos in the mid-region
of the body (Viviparous monogenean). Posterior
Ginger lethal concentration-50 (LC ):
50
end has the organ of fixation, opisthaptor, which
The result of LC of ginger for C. gariepinus
50
is guarded with a number of marginal hooklets
after 96 hours appeared to be 192 mg/L
and a central one pair of hooks (Fig. 4&5).
(Table 2).
Mediterranean Aquaculture Journal 2008 1(1); 1-9
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Study on Some Ectoparasitic Diseases of Catfish
Table 2: Conducting of ginger LC for Clarias gariepinus
50
(Fig. 6).
after 96 hours.
Exposure
Fish
No. of
A
B
AXB
dose
Numbers/
dead
(mg/L)
groups
Fish
20
0
0
0
0
40
0
0
0
60
1
0.5
10.0
80
2
1.5
30.0
100
10
3
2.5
20
50.0
120
5
4
80.0
140
7
6
120
160
8
7.5
150
180
9
8.5
170
200
10
9.5
190
?
100
800
LC = 192 mg/L
50
Fig. 6: Ulceration and bloody erosion in the skin and fins of
(A) is the mean of dead fish between two successive doses.
C.gariepinus due to overdose of ginger.
(B) is dose differences between two successive doses.
Estimation of the aquarium water quality
Efficacy of Ginger bath on the ectoparasites
before and during treatment:
infesting C. gariepinus:
The estimation of water parameters (Dissolved
The results of ginger efficacy on the infested C.
oxygen, pH and total ammonia) pre and during
gariepinus with mixed infestation of Trichodina,
treatment with ginger revealed that the water
Epistylis and Gyrodactylus spp. indicated that
quality during treatment was better than pre-
long exposure of infested fish for three days
treatment especiallythe total ammonia which
(long bath) to ginger at concentration 10 mg/L
decreased in value in comparing with pre-
was insufficient to eradicate the protozoa and
treatment (Table 4).
monogenea while ginger concentration of 20
mg/L was sufficient to eradicate the protozoa
Discussion
(Trichodina and Epistylis spp.) but can not
eradicate the monogenean (Gyrodactylus spp.)
All ectoparasites appear to be an important
(Table 3). Overdose of ginger caused ulceration
pathological stressor affecting fish populations in
and erosion in the skin and fins of catfish
Table 3: Efficacy of ginger bath on ectoparasites infesting C. gariepinus.
Fish groups Ginger doses
Period of
Trichodina,spp. 8/
Epistylis,spp.18/
Gyrodactylus,spp.
mg/l
treatment/day
field (10X)
field(10X)
6/field(10X)
1
8
18
6
1st group
(15)
10
2
6
10
5
3
4
5
4
2st group
(15)
20
1
5
6
6
2
3
2
4
3
-
-
3
3st group
(15)
none-treated
1
8
18
6
2
11
18
6
3
13
20
8
6
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Jihan F. K. Abo-Esa
Table 4: Estimation of some water parameters pre and during ginger treatment (20 mg/L).
Parameter
24 hours pre-treatment During treatment
1st day
2nd day
3rd day
1-Dissolved oxygen (PPM)
5.6
6.4
6.5
6.7
2- pH
7.1
6.92
7.2
7.2
3-Total ammonia (PPM)
14.2
9
10.1
11.2
the water stratum. In the present study, the gross
15–18 and 6-8 parasites per field, respectively
clinical appearance of infested C. gariepinus
Table (1). These numbers of ectoparasites per
with ectoparastic protozoa (Trichodina and
fish were considered a moderate infestation in
Epistylis spp.) and the monogenean Gyrodactylus
O. niloticus as mentioned by El-Tantawy (2003).
spp. demonstrated pale skin, excessive mucus
It may be attributed to that, in wild, catfish have
secretion and skin erosion with local ulcerative
many species of parasites with small numbers
lesions (Fig. 1 a&b). These results were similar
(FAO 2007).
to that recorded by (Kuperman and Matey 2000
and El-Tantawy 2001).
The taxonomy of the isolated Trichodina,
Epistylis and Gyrodactylus spp. was typical
In Table (1), the total average of ectoparasites
to that reported by Paperna (1996), Huh et al.
was 60%. This result was lower than that of (El-
(2005) and Rotkiewicz (2006) Moreover, their
Tantawy 2001) (100% for protozoa and 76% for
morphological identification was similar to the
monogenea) in Oreochromis niloticus and higher
description of El-khatib (1993), Lynn (2002)
than that recorded by Diab et al. (2006) as (44.4%)
and Lome (2006).
among cultured C. gariepinus in Abassa. In
addition, the average of the Trichodina spp. Fig.
In respect to the undesirable side effects of the
(2) in the infested catfish was 20% which was
chemical treatment of parasitic diseases and its
lower than the finding of Hanna (2001) who
public health hazards, the herbal treatment is
recorded Trichodina spp. from gills of common
taken place to relieve the harmful side effects
carp. With concern to Epistylis spp. Fig. (3), its
of chemicals. So, in this study, the ginger was
average was 15%. This result was lower than
screened for its efficacy in treating C. gariepinus
that recorded by El-Tantawy and Younis (2003)
infested with a mixed infestation of Trichodina,
in Oreochromis niloticus (25%).
Epistylis and Gyrodactylus spp. To avoid
overdosing of ginger and to determine an effective
The average of monogenean Gyrodactylus spp.
control dose for ectoparasites, a bioassay of
Fig. (4, 5) was 30% among infested C. gariepinus.
ginger LC after 96 hours was conducted (Table
50
This result was lower than that obtained by
2). The value of 192 mg/L ginger after 96 hours
(Endraws 2001). Also, a higher average (100%)
appeared to be its lethal concentration 50 for the
was recorded by Paperna (1996) in the Nile fish.
exposed fish. So, the safe ginger dose must be
These variations in results might be attributed to
19.2 mg/L which is 10 times lower than such
the inhibitive quality of physical (Depth, current,
value as recommended by US Environmental
temperature) and chemical (Oxygen, salinities)
protection Agency (Boyd 1998) but in this
factors of the environment and fish species.
study, the safe and effective dose of ginger for
the exposed catfish was 20 mg/L which was
In the present study, the intensity of the
approximately near the calculated safe dose 19.2
ectoparasitic protozoa Trichodina, Epistylis and
mg/L. The higher ginger doses than 20 mg/L
the monogenean Gyrodactylus spp. were 8-10,
caused various ulcerations and bloody erosions
Mediterranean Aquaculture Journal 2008 1(1); 1-9
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Study on Some Ectoparasitic Diseases of Catfish
in the skin and fins of the treated fish (Fig. 6).
Conclusion
The efficacy of herbal treatment with ginger
Ginger has a good effect on treating ectoparasitic
(long bath) on ectoparasites of catfish (Table 3)
protozoa Trichodina and Epistylis spp. at dose
determined that the suitable dose of ginger for
20 mg/L. It also improves the water quality
eradication of ectoparasitic protozoa Trichodina
for aquaculture operation with absence of
and Epistylis was 20 mg/L for three successive
undesirable side effects in comparison to other
days. On the other hand, neither the doses of 10
chemicals used in this trend.
mg/L nor 20 mg/L of ginger was sufficient to treat
the monogenean Gyrodactylus spp. That dose of
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