Veterinary Archives, Vol. 79 No. 6, 2009.
Original scientific paper
Cypermethrin induced respiratory and behavioural responses of the freshwater teleost, Labeo rohita (Hamilton)
Shambanagouda Rudragouda Marigoudar
; Department of Studies and Research in Zoology, Karnatak University, Dharwad, Karnataka, India
Raichur Nazeer Ahmed
; Department of Studies and Research in Zoology, Karnatak University, Dharwad, Karnataka, India
Muniswamy David
; Karnatak University’s Research Laboratory, Toxicology Division, Department of Zoology, Karnatak Science College, Dharwad, Karnataka, India
Abstract
A short term definitive test by the static renewal bioassay method was conducted to determine the acute toxicity (LC50) of technical grade pyrethroid insecticide, cypermethrin (92.25%) in freshwater indigenous carp, Labeo rohita. Carp fingerlings were exposed to different concentrations (2.0 to 6.0 μg/L) of cypermethrin for 96 h. The acute toxicity value was found to be 4.0 μg/L and one fi fth of LC50 (0.57 μg/L) was selected for sub acute studies. Behavioural patterns and oxygen consumption were studied in lethal (1, 2, 3 and 4 d) and sub
lethal concentrations (1, 5, 10 and 15 d). Carp in toxic media exhibited irregular, erratic and darting swimming movements, hyper excitability, loss of equilibrium and sinking to the bottom, which might be due to inactivation of (AChE) acetyl cholinesterase activity which results in excess accumulation of acetylcholine in the cholinergic synapses leading to hyperstimulation. Variation in oxygen consumption (1.289 to 17.409 %; 20.580 to 109.77 %) was observed in both lethal and sub lethal concentrations of cypermethrin respectively. Alterations in oxygen consumption may be due to respiratory distress as a consequence of impairment in oxidative metabolism. Fish in the sublethal concentration were found under stress, but that was not fatal.
Keywords
cypermethrin toxicity; oxygen consumption; behaviour; Labeo rohita
Hrčak ID:
53085
URI
Publication date:
18.12.2009.
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