The Effects of a 24-hour Exposure to Carbaryl or Atrazine on the Locomotive Performance of Juvenile Spotted Salamanders (Ambystoma maculatum)

Amphibian ecotoxicology research has traditionally focused on chronic aquatic exposure of early life stages. However, multiple studies have shown that the survival of juvenile salamanders, frogs, and toads has the largest impact on population growth. Studies on species within the genus Ambystoma have shown that juvenile salamanders are the most likely of any life stage to disperse to new ponds. Because chemical contaminants are widely used throughout agricultural lands in the U.S. and have been shown to have effects on the central nervous system, it is important to determine any potential role they might have on locomotive performance. Our study sought to determine whether a 24-hour exposure to environmentally relevant concentrations of carbaryl (a neurotoxic insecticide) and atrazine (an herbicide) affected the locomotive performance of juvenile spotted salamanders (Ambystoma maculatum). Exposed salamanders were tested for either speed (max-burst in a U-shaped Plexiglas track) or endurance (time spent running at a constant speed on a treadmill). We found that carbaryl and atrazine treatment did not significantly affect speed or endurance ability. However, we did find that individuals exposed to carbaryl in the speed test experienced significantly increased fatigue throughout the speed trials. In addition, we found that mass to be significantly correlated with speed ability. Overall, our study suggests that a 24-hour exposure to environmentally relevant concentrations of carbaryl and atrazine does not directly significantly affect maximum burst speed or endurance ability in juvenile spotted salamanders

Histopathological analysis of carbaryl-induced toxicity in the spleen of Levantine frog, Pelophylax bedriagae (Anura: Ranidae)

WOS: 000443012600032PubMed ID: 29931639This study describes the histopathological effects of carbaryl in the spleen of Levantine frog, Pelophylax bedriage. Due to its primary role in immune system, it is important to research the toxic effects of pesticides, which play an important role in environmental pollution, on spleen. To that end, adult frogs were exposed to carbaryl for 96 h. Experimental groups contained low dose, (0.05 mg/g), medium dose (0.1 mg/g) and high dose (0.2 mg/g). After following exposure to carbaryl, the frogs were euthanised and dissected. In low-dose group, there were no important changes in spleen tissue. In medium-dose group, prominence in haemorrhage just below the capsule and an increase in the melanomacrophage number were determined. In high-dose group, in addition to increases in the melanomacrophages, separations in capsule, haemorrhage below capsule and within splenic tissue, sinusoidal enlargement, congestion in dilated sinusoid, hypertrophic plasma cells and fibrosis were determined as important histological lesions in exposed frogs. This study clearly showed that carbaryl caused important histopathological damages in splenic tissue of Pelophylax bedriagae. In view of these findings, it can be said that this insecticide has the capacity to disrupt spleen' functions