Original scientific paper
The sublethal effects of (2,4-Dichlorophenoxy) acetic acid (2,4-D) on narrow-clawed crayfish (Astacus leptodactylus Eschscholtz, 1823)
A. Çağlan Karasu Benli
; Department of Environmental Sciences, Institute of Natural And Applied Science, Ankara, Turkey
Duygu Şahin
; Department of Medical Biochemistry, Ankara, Turkey
Mahmut Selvi
; Department of Science Education, Teknikokullar, Ankara, Turkey
Rabia Sarıkaya
; Department of Primary School Education, Ankara, Turkey
Burcu Koçak Memmi
; Gazi University, Insecticide Test Laboratory, Hacettepe University, Beytepe, Ankara, Turkey
Aylin Sepici Dinçel
; Department of Medical Biochemistry, Ankara, Turkey
Abstract
2,4-D is a widely used phenoxy herbicide, potentially toxic to humans and biota. The objective of the present study was to reveal short term sublethal effects of 2,4-D on narrow-clawed freshwater crayfish (Astacus leptodactylus Eschscholtz, 1823), based on histology, total haemocyte counts, selected haemolymph parameters, and oxidative stress parameters. In the laboratory conditions crayfish specimens were exposed to 9 mg L-1 of 2,4-D for one week. Experiments were conducted under semi-static conditions in 20 L-capacity aquaria where 10 freshwater crayfish were stocked per aquarium. Exposure (experimental) and control groups were used and the experiments were repeated two times. No mortality and behavioural changes were recorded during the experiments. Total haemocyte counts decreased significantly, while haemolymph glucose levels increased (P<0.05), when compared to the control group. Haemolymph levels of calcium, chloride, sodium, potassium, magnesium, total protein, and lactate did not change. Exposure resulted with increased levels of malondialdehyde (MDA) only in hepatopancreas. However, results of gill FOX assay showed a significant decrease in oxidative stress parameters (P<0.05). MDA levels of gill and abdominal muscle tissues and FOX levels of hepatopancreas and abdominal muscle tissues did not change when compared to the control group. Significant histopathological alterations were observed both in hepatopancreas (multifocal deformations in tubule lumen) and gill tissue (melanisation of gill lamella). Exposure of crayfish even to a sublethal concentration of 2,4-D alters histopathology and lipid peroxidation due to stress. Biomarkers studied here seem to be useful for the assessment of adverse/toxic effects of pesticides on non-target, indicator aquatic organisms.
Keywords
haemolymph; herbicide; histology; oxidative stress; toxicity
Hrčak ID:
170510
URI
Publication date:
14.12.2016.
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