Mixed toxicity of chlorpyrifos and dichlorvos show antagonistic effects in the endangered fish species golden mahseer (Tor putitora).

Autor: Kunwar PS; Central Department of Zoology, Tribhuvan University, Kirtipur, Kathmandu, Nepal; Central Fisheries Promotion and Conservation Centre, Balaju, Kathmandu, Nepal. Electronic address: prabeshkunwar@yahoo.com., Parajuli K; Central Department of Zoology, Tribhuvan University, Kirtipur, Kathmandu, Nepal., Badu S; Central Department of Zoology, Tribhuvan University, Kirtipur, Kathmandu, Nepal., Sapkota B; Central Department of Zoology, Tribhuvan University, Kirtipur, Kathmandu, Nepal., Sinha AK; Department of Aquaculture and Fisheries, University of Arkansas at Pine Bluff, 1200 North University Drive, Pine Bluff 71601, AR, USA., De Boeck G; Systemic Physiological and Ecotoxicological Research, Department of Biology, University of Antwerp, Groenenborgerlaan 171, BE-2020 Antwerp, Belgium., Sapkota K; Central Department of Zoology, Tribhuvan University, Kirtipur, Kathmandu, Nepal. Electronic address: kumar.sapkota@cdz.tu.edu.np.
Jazyk: angličtina
Zdroj: Comparative biochemistry and physiology. Toxicology & pharmacology : CBP [Comp Biochem Physiol C Toxicol Pharmacol] 2021 Feb; Vol. 240, pp. 108923. Date of Electronic Publication: 2020 Oct 26.
DOI: 10.1016/j.cbpc.2020.108923
Abstrakt: Golden mahseer (Tor putitora) is an economically important but endangered fish species in many countries. Increasing pesticide application can possess a threat to this species but their sensitivity to pesticides, typically chlorpyrifos and dichlorvos, is unknown. We determined 96 h-LC 50 of chlorpyrifos and dichlorvos to be 0.753 mg/L and 12.964 mg/L, respectively, indicating higher toxicity of chlorpyrifos than dichlorvos. Despite the same mode of action, their joint effect was antagonistic, with an additive index value of - 0.58 at 96 h-LC 50 . Moreover, to get insights in the temporal sub-lethal effects, fish were exposed to 10% and 50% of the 96 h-LC 50 values of the respective pesticides. Aerobic metabolism, opercular movements, and feeding behavior were examined for sub-lethal end-points following 24 h, 48 h, 72 h and 96 h exposure. Both chlorpyrifos and dichlorvos in single exposures induced a significant drop in oxygen consumption rate; while it was significantly elevated in the mixed pesticide exposure. Accelerated opercular movements were observed in all pesticide treatment groups but were more persistent in chlorpyrifos treatments. Reduced feeding attempts were more pronounced in chlorpyrifos and mixture treatments wherein feeding attempts dropped to zero. Overall, the acute toxicity data reported in the present study can be used to assess the maximum tolerance level of golden mahseer to chlorpyrifos and dichlorvos, and their mixture. Furthermore, the sub-lethal end point responses can be applied in monitoring the environmental risk posed by these waterborne pesticides either individually or in combination to the aquatic life.
(Copyright © 2020 Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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