Effects of deltamethrin on some haematological parameters of brown trout
(Salmo trutta fario)
Tayfun Karatas*
Health Services Vocational School,
Agri Ibrahim Cecen University, Agri, 04100, Turkey.
Received: 16-05-2015 Accepted: 13-06-2015
Abstract
This study was to assess the effects of deltamethrin on some haematological parameters of brown trout (Salmo trutta fario).
During the 4 day, 10 brown trout were exposed to two different concentrations of Deltamethrin which they were
20% (0.91 g·L-1) and 40% (1.88 g·L-1) respectively, (LC50=4.7 g·L-1). The results obtained from this study showed that
the White Blood Cell (WBC), Hemoglobin content (Hb), Hematocrit percentage (PCV), Mean Corpuscular Volume (MCV)
and Mean Corpuscular Hemoglobin (MCH) were decreased in two treated groups when compared to the control (p<0.05).
However, the number of Red Blood Cell (RBC) increased in deltamethrin treated fish (p<0.05). Mean Corpuscular
Hemoglobin Concentration (MCHC) values were insignificant when compared to control group (p>0.05).
Key words: Brown trout, Deltamethrin, Effect, Hematological parameters, Toxicity.
Introduction
Deltamethrin is extensively used in agriculture, for
controlling pests, insects and vectors of endemic diseases,
protecting seeds during storage and fighting household
insects because of their low environmental persistence
(Braguini et al., 2004). The extensive use of deltamethrin
on land may be washed into surface water and can adversely
influence or kill the life of aquatic organisms and other higher
animals. Aquatic organisms, particularly fish, are highly
sensitive to Deltamethrin. Due to their lipophilicity,
pyrethroids have a high rate of gill absorption, which would
be a contributing factor in the sensitivity of the fish to aqueous
pyrethroid exposures. Fish seem to be deficient in the enzyme
system that hydrolyzes pyrethroids (Bhattacharjee and Das,
2014). It has been found that the fish exhibit several
symptoms of stress when treated with deltamethrin (Datta
and Kaviraj, 2003). Generally, deltamethrin affects the
overall physiological profile in fish with particular reference
to the energy metabolism, biochemical and haematological
characteristics (El-sayed et al., 2007). The mechanism of its
neurotoxic effectiveness is the same as that of other type II
pyrethroids: blockage of the sodium channels and inhibition
of ã-aminobutyric acid receptors. Effects of deltamethrin on
nervous, respiratory and haematological systems have been
reported (Golow and Godzi, 1994). Possible toxicological
actions of the pyrethroids include disruption of calcium and
phosphate homeostasis and abnormalities in haematopoiesis
and protein synthesis (Svobodova et al., 2003). Deltamethrin
causes severe morphological alterations in the gills and liver
and causes toxic effects on the hematopoietic organs, liver
and gills (Yildirim et al., 2006). Deltamethrin may disturb
the calcium and phosphate homeostasis and may lead to an
effect on the reproductive state of the fish (Maund et al., 2002).
Many studies conducted in recent years have showed the
harmful effects on fishes and the aquatic ecosystem of
pesticides. Haematological parameters in fish living in the
different environmental conditions are very important for
toxicological studies (Schlenk, 2005; Banaee et al., 2008;
Banaee et al., 2011). Therefore, they are used as indicators
of the physiological stress response to endogenous and
exogenous changes in fish (Bhattacharjee and Das, 2014).
This study was to determinate the effects of deltamethrin on
haematological parasmeters in brown trout.
MATERIALS AND METHODS
Collection and maintenance of fish: Fish samples were
obtained from the brown trout farm of a commercial
enterprise. The live Brown trout (n = 30) used in this study
were mature, healthy, 1 years old and with an average weight
of 150–190 g. The average water temperature was 10 ± 2oC
during the tests. At the time of sample collection, fish had
been fed with a commercial trout feed at 2% body weight
once a day. Prior to the experiment, fish in each group were
kept in 1 x 1.2m (wide-deep) fiber-glass tanks for 1 month.
Aeration was provided along the experiments. The water
2 INDIAN JOURNAL OF ANIMAL RESEARCH
quality parameters were measured as O2
= 8.5 ppm,
pH = 7.4, SO4
-2 = 0.30 mg/L, PO4
-3 = trace, NO3
– = 3.15 mg/
L, NO2
–
= trace and conductivity = 230 ls/cm (Karatas, 2014).
Acute toxicity: The effect of acute toxicity of the agricultural
toxicant, deltamethrin was determined as LC50 (96h). For
this purpose, 3 treatments including control were set up to
test toxicity; each treatment was replicated three times with
10 fish per tank with 60 liters water capacity. Fishes were
exposed to deltamethrin at a nominal concentration of
0.0 g·L-1 (control group), 0.91 (20%) g·L-1and 1.88 (40%) g·L-1
,
respectively, which were equivalent to approximately 30%
and 60% of 96 h LC50 value (4.7g·L-1) for 4 days toxicity
testing (Banaee et al., 2011). Mortality was recorded at
24, 48, 72 and 96 h after the beginning and dead fishes were
removed immediately from the tank.
Haematology assay: After the test period, fish were
quickly taken out from the water and held firmly on a bench
with a cloth covering the head to obtain blood samples
and blood samples were withdrawn from caudal vessels
by a vacuum syringes and then samples were taken
haematology tubes. The tubes filled with blood samples
were shaken a few times in order to prevent freezing.
Handling time of fish was less than 1 minute to minimize
stress effects (Karatas et al., 2014).
At the time of blood sampling, the appropriate
smears were prepared for Giemsa staining. The smears were
air-dried, fixed in 96% ethanol for 30 minutes and stained
with Giemsa staining about 30 minutes. The smears were
examined for leucocyte differential count under a
compound microscope. The haematological parameters
were examined for erythrocyte count (RBC, ×106
/mm3
),
hematocrit (Hct, %), haemoglobin (Hb, g/dL), mean
corpuscular haemoglobin (MCH= (Hb in gr / RBC in
millions) × 10pg ), mean corpuscular volume (MCV=
(packed cell volume as percentage/RBC in millions) ×
103, fl), mean corpuscular haemoglobin concentration
(MCHC= (Hb in g/packed cell volume) × 100 g per 100 mL, %),
leucocyte count (WBC×104
/mm3
and differential leucocyte
count (Klont et al., 1994).
Statistical analysis: The data obtained from this study was
subjected to various statistical tools. The differences in the
means (±SEM) between groups were assessed using
Independent Samples-t test, adjusted to 95% confidence
limits some important. SPSS program version 15.0 was used
for statistical analysis.
Results and discussion
Sub-lethal concentrations of deltamethrin were
equivalent to approximately 20% and 40% of 96 h LC50
value for 4 day toxicity testing. In some cases, fish exposed
to deltamethrin exhibited vertical and downward swimming,
patterns, swimming near the water surface. Variations in
haematology parameters such as RBC, WBC, PCV, Hb,
MCH, MCV, MCHC levels were showed in Table 1. WBC,
Hb and PCV levels were reduced after exposure to the
pesticide deltamethrin. Nevertheless, RBC value increased
significantly. Significant differences were observed in the
RBC, WBC, PCV, Hb levels (p<0.05). The MCV and MCH
values of exposed fish showed a significant decrease
(P<0.05). There were slight fluctuations in the MCHC values.
But, MCHC values were not significantly different from each
other during the study (P>0.05).
Haematological parameters have been
acknowledged as valuable tools for monitoring fish health,
confirming maturation and monitoring any changes in the
quality of water (Satheeshkumar et al., 2003). Therefore, a
change in water is one of the most important factors for fish
haematology. On the basis of haematological studies, it is
done to determine the sensitivity to environmental conditions
and toxic substances of fish (Fernandes and Mazon, 2003).
The reduction of oxygen-carrying capacity in fish
may be associated with a decrease in hemoglobin
concentration that is affected by deltamethrin. The need for
hemoglobin content increased. Hb content increasing may
depend on the deformed osmoregulation balance of fish. This
chemical compound appears to interfere with the ability to
bind hemoglobin to oxygen during respiration (Atamanalp
et al., 2010). Kumar et al. (1999), Atamanalp and Yanik
(2003) and Atamanalp et al. (2010) reported a significant decrease in Hb contents of O. mykiss and brown trout which
can be related with Hb destroying or a decrease in the rate
of Hb synthesis. Both the decrease in hemoglobin
concentration and the increase in the number of RBC can be
explained with the increase in respiration of the fish for the
oxygen they need. Similar changes in the white blood cell
are also reported by Svobodov´a et al. (2003) in carp
following acute toxicity with permethrin and reported by
Velisek et al. (2007) in rainbow trout following acute toxicity
with deltamethrin. Bradbury and Coast (1989) reported signs
of fenvalerate poisoning in fish.
Haematological parameters of brown trout to the
acute effect of the deltamethrin at a 0.91 and 1.88 µg/L-1
concentration were a significant decrease in white blood cell,
haematocrit, and haemoglobin content in blood plasma as
compared to the control group. In freshwater catfish,
Heteropneustes fossilis, the Hb (%) decreased after 30 days
exposure to deltamethrin (Sayeed et al., 2003). In a study,
Pimpao et al. (2007) observed an increase in the total
erythrocyte counts in catfish (Ancistrus multispinis)
intoxicated with deltamethrin, while, El-Sayed et al. (2007)
observed a significant increase in erythrocytes, hemoglobin
and hematocrit rate in Nile tilapia (Oreochromys niloticus)
exposed to the same toxic substance.
Significant decrease was observed in MCH and
MCV values are similar to other studies. MCH was
significantly decreased in C. idella after 48 h exposure to
fenvalerate (Mughal et al., 1993). The decreased MCH and
MCV levels may be a sign of hypochromic microcytic
anemia (Shakoori et al., 1996). In contrast to our findings,
there were increases in Hb and MCH values in T. mossambica
exposed to cadmium chloride (Aziz et al., 1993) and C. idella
exposed to sublethal doses of mercuric chloride (Shakoori
et al., 1996) and in O. mykiss exposed to cypermethrin
(Atamanalp et al., 2002). RBC indices such as MCV and
MCHC fell during prolonged exposure to Mercuric
chloride (Mousevi and Yousefian, 2012). The decrease in
other hematological parameters is attributable to reduced
MCV (Ahmad et al., 1995) while Carvalho and Fernandes
(2006) found no significant effects in MCHC fish,
Prochilodus scrofa on copper toxicity, that are
consistent with present study regarding no significant
in MCHC values.
Conclusion
Deltamethrin toxicity in brown trout showed that it
causes varied effects including oxidative stress,
haematological changes. Also, 40% concentration of
deltamethrin was found to be toxic to brown trout. Further
research is needed since different fish species and different
growing stages of fish may respond to pollution factors at
different levels.