Endosulfan exposure disrupts pheromonal systems in the red-spotted newt: Amechanism for subtle effects of environmental chemicals

Because chemicals introduced into the environment by humans can affect both long-term survivorship and reproduction of amphibians, discovering the spe cific mechanisms through which these chemicals act may facilitate the devel opment of plans for amphibian conservation. We investigated the amphibian p heromonal system as a potential target of common environmental chemicals. B y treating female red-spotted newts, Notophthalmus viridescens, to a common ly used insecticide, endosulfan, we found that the pheromonal system is hig hly susceptible to low-concentration exposure. The impairment of the pherom onal system directly led to disrupted mate choice and lowered mating succes s. There were no other notable physiologic or behavioral changes demonstrat ed by the animals at the insecticide concentrations administered. Our findi ngs suggest that the amphibian pheromonal system is one of the systems subj ect to subtle negative effects of environmental chemicals.