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Effects of diazinon on
blood parameters in the African catfish (Clarias
gariepinus)
Adedeji, O. B.*, Adeyemo, O. K. and Agbede, S. A.
Faculty of
Veterinary Medicine, University of Ibadan, Nigeria.
*Corresponding author.
E-mail:
oluadedeji2001@yahoo.com or
olufemi.adedeji@mail.ui.edu.ng. Tel: +23427515765 or
+2348034917181.
Accepted
17 February, 2009 |
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The aim
of this study was to assess the effect of diazinon
[0,0-diethyl 0-(2-isopropyl-6-methylpyrimidin-4yl)
phosphorothioate] on cultured and wild African catfish (Clarias
gariepinus). The effect was assessed based on results of
acute toxicity tests and on a comparison of results of
haematological examination of a control and an experimental
group exposed to DiazintolR pesticide preparation
(active substance 162 mg.l-1 of diazinon). The
acute toxicity test lasting 96 h was performed
semi-statically on the African catfish of mean weight
350 ± 15 g,
and mean total length of 35 ± 2.0 cm.
Examination of erythocyte and leucocyte profile was
performed on 16 control and 20 experimental specimens of the
catfish after 96 h of exposure to DiazintolR in
concentration of 9.4 mgl-1. The 96 h LC50
value of DiazintolR for the African catfish is
6.6 mgl-1. The experimental group of the African
catfish showed significantly lower values (p < 0.05) of
erythocyte count (RBC), haemoglobin content (Hb) and
haematocrit (PCV) compared to the control group. Values of
MCV, MCH and MCHC were comparable in both groups during the
study. On the contrary, there was a significant decrease in
leucocyte count (p < 0.05), as well as in both the relative
and absolute lymphocyte count (p < 0.05) and a significant
increase in both the relative and absolute count of
developmental forms of neutrophile granulocytes: myelocytes
(p < 0.05) and metamyelocytes (p < 0.05) in the experimental
group. Relative and absolute count of monocytes and both the
band- and segmented neutrophile granulocytes was comparable
in both groups during the study. Changes in values of both
the erythocyte and leucocyte profile after exposure to
diazinon-based preparation may be referred to disruption of
haematopoiesis as well as to a decrease on non-specific
immunity of the fish.
Key
words:
Pesticide, diazinon acute toxicity, erythocyte profile,
leucocyte profile, catfish. |
