Dichlorvos and Paraquat induced spatial avoidance response: A more realistic determinant of population decline of Oreochromis niloticus

Authors

  • Evelyn Tibiebi Soriwei Laboratory of Ecotoxicology, Department of Zoology, University of Lagos, Akoka-Yaba, Lagos, Nigeria
  • Hilary Chikaelo Umeokeke Laboratory of Ecotoxicology, Department of Zoology, University of Lagos, Akoka-Yaba, Lagos, Nigeria https://orcid.org/0000-0002-4285-8393
  • Nnamdi Henry Amaeze Laboratory of Ecotoxicology, Department of Zoology, University of Lagos, Akoka-Yaba, Lagos, Nigeria. https://orcid.org/0000-0003-4588-7066
  • Olusola Ojo Ogunfeitimi Laboratory of Ecotoxicology, Department of Zoology, University of Lagos, Akoka-Yaba, Lagos, Nigeria https://orcid.org/0000-0002-5087-1272
  • Suuru Ayomide Labinjo Laboratory of Ecotoxicology, Department of Zoology, University of Lagos, Akoka-Yaba, Lagos, Nigeria

DOI:

https://doi.org/10.5132/eec.2021.01.04

Abstract

The present study evaluated the ability of Dichlorvos and Paraquat to provoke avoidance response in fingerlings of Nile tilapia Oreochromis niloticus and estimate the population immediate decline (PID). The non-forced multi-compartmented system used for non-forced assays, were constructed to allow free movement of fishes along six compartments. Fishes (n=3 per compartment/treatment, totaling 18 per system) were exposed to a gradient of Dichlorvos (1.0, 2.0, 4.0, 5.0 and 6.0 mg L-1) and Paraquat (10.0, 30.0, 50.0, 70.0, 100.0 mg L-1) and their distribution were recorded at 20 min interval for a 3-h period. Mortalities recorded in forced exposures were 17% and 0% at lowest concentrations and, 67% and 83% at highest concentrations for Dichlorvos and Paraquat correspondingly. For non-forced exposure, fishes presented a significant (p < 0.005) gradient-dependent spatial avoidance for both pesticides after 3-h. They avoided the lowest concentrations of Dichlorvos and Paraquat (1.0 and 10.0 mg L-1) by 40% and 90% respectively and 100% at the highest concentrations for both pesticides. The PID was driven by avoidance behavior rather than mortality. This result indicates that the dangers of pesticide contamination is not only in their toxicity to organisms, but also, in habitat selection processes by organism resulting in serious environmental turbulence.

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Author Biographies

Evelyn Tibiebi Soriwei, Laboratory of Ecotoxicology, Department of Zoology, University of Lagos, Akoka-Yaba, Lagos, Nigeria

Department of Zoology, Research Assistant.

Hilary Chikaelo Umeokeke, Laboratory of Ecotoxicology, Department of Zoology, University of Lagos, Akoka-Yaba, Lagos, Nigeria

Department of Zoology, Research Assistant.

Nnamdi Henry Amaeze, Laboratory of Ecotoxicology, Department of Zoology, University of Lagos, Akoka-Yaba, Lagos, Nigeria.

Department of Zoology, Senior Lecturer.

Olusola Ojo Ogunfeitimi, Laboratory of Ecotoxicology, Department of Zoology, University of Lagos, Akoka-Yaba, Lagos, Nigeria

Zoology Department, Research Assistant.

Suuru Ayomide Labinjo, Laboratory of Ecotoxicology, Department of Zoology, University of Lagos, Akoka-Yaba, Lagos, Nigeria

Department of Zoology

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Published

03-10-2021

How to Cite

Soriwei, E. T., Umeokeke, H. C., Amaeze, N. H., Ogunfeitimi, O. O., & Labinjo, S. A. (2021). Dichlorvos and Paraquat induced spatial avoidance response: A more realistic determinant of population decline of Oreochromis niloticus. Ecotoxicology and Environmental Contamination, 16(1), 27–34. https://doi.org/10.5132/eec.2021.01.04

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Original Articles