Theses and Dissertations

Date of Award

5-2024

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Ocean, Coastal, and Earth Sciences

First Advisor

MD Saydur Rahman

Second Advisor

Alejandro Fierro

Third Advisor

Amit U. Raysoni

Abstract

Pesticides are used widely to control weeds and pests in agricultural settings but harm non-target aquatic organisms. We examined the effect of short-term exposure (one week) to pesticide mixtures (low dose: 0.5 μg/L Roundup®, 0.5 μg/L 2,4-D, and 0.4 μg/L atrazine; high dose: 1 μg/L Roundup®, 1 μg/L 2,4-D, and 0.8 μg/L atrazine) on American oyster (Crassostrea virginica, an important shellfish and seafood species) under controlled laboratory conditions. Histological analyses demonstrated the atrophy in oysters' gills, digestive glands, and connective tissue. The protein concentrations and glucose levels dropped significantly in the high-dose treatment. The number of hemocytes in connective tissue increased in low- and high-dose treatments. Immunohistochemical analyses showed significant upregulations in NTP and Na+/K+ ATPase expressions in the tissues of oysters. However, pesticide treatments decreased the amount of mucous in the gills and digestive glands. Our results suggest that exposure to pesticide mixtures causes morphological changes in oysters' tissues and alters body fluid properties, osmoregulation, antioxidant conditions, and homeostasis, leading to impaired oysters' physiological functions.

Comments

Copyright 2024 Asif Ahmed.

https://go.openathens.net/redirector/utrgv.edu?url=https://www.proquest.com/pqdtglobal1/dissertations-theses/effect-short-term-exposure-pesticide-mixture-on/docview/3085283702/sem-2?accountid=7119

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