The Effects of 2; 4-D, Triclopyr, Dicamba, and Pyraflufen Herbicide on Xenopus laevis Survival, Growth, Behavior, and Pathology

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Biology | Life Sciences


Elizabeth Wurdak, Biology


Manufacturers of herbicides that combat broad-leafed plants warn that they may be toxic to fish and aquatic invertebrates. Six days post hatch, African clawed frogs (Xenopus laevis) were exposed to either 5.6ml (100%) or 0.56ml (10%) of 40 ml solution containing a combination of 2,4-D, Triclopyr, Dicamba and pyraufen ethyl herbicides for 7 or 16 days, respectively. The 100% group had a survival fraction of 0.18; this was a significant difference (p < 0:0001) from the survival fractions of 0.794 and 0.8 for the 10% group and control group, respectively. Exposed tadpoles were lethargic, observably less hungry, displayed abnormal swimming, and demonstrated a higher variability in mass. Tadpoles, after being preserved in buffered formalin; embedded in paraffin; sectioned; and stained with either hematoxylin and eosin, Mallory Trichrome stain, or the periodic acid-Schiff were examined under the light microscope. There were no striking differences in the gut. Examinations under the SEM revealed no external differences.