Toxicity of endosulfan to aquatic stages of anuran amphibians

Abstract

Abstract-The toxicity of endosulfan insecticide to wood frog (Rana sylvatica) embryos and tadpoles of wood frogs, American toads (Bufo americanus), and green frogs (R. clamitans) was examined in the laboratory. Following exposures to 0.03 to 0.4 mg/L endosulfan for 96 h, sublethal effects and postexposure mortality were assessed. In another experiment, premetamorphic American toad tadpoles (with developing hindlimbs but unerupted front legs) were exposed to 0.3 mg/L endosulfan for 96 h. The exposed wood frog embryos hatched successfully and were morphologically indistinguishable from the unexposed animals at the end of the 10-d postexposure period. However, extensive paralysis of exposed tadpoles of all three species occurred; all but one of the exposures resulted in 100% of the tadpoles experiencing paralysis at some point during the exposure or recovery period. Postexposure mortality of tadpoles was high and occurred at the lowest exposure concentrations (0.041-0.053 mg/L) for each species exposed as 2-week-old tadpoles. Newly hatched American toad tadpoles were more tolerant than tadpoles of the other two species, but no clear species differences in sensitivity of 2-week-old tadpoles was apparent. American toad premetamorphs exposed to endosulfan did not recover from the effects of the exposure. Our results indicate that the aquatic stages of anuran amphibians may be sensitive to levels of the pesticide endosulfan that could reach their habitat by means of direct applications or drift from aerial spraying.

Effects of Endosulfan (Thiodan 35 EC®) on Meiofauna Community Through a Microcosm Approach

“…Although kinorhynchs present their bodies covered by a strongly water-repelling cuticle (Giere, 2009), a fact that favors the passive uptake of pesticides, this group showed of the endosulfan applied through the Thiodan pesticide may have been degraded to endosulfan sulfate (unmeasured values). Both endosulfan isomers exhibited relatively short half-lives and the present results are consistent with other microcosm studies that reported significant losses of more than 50% in two weeks or even during the first days after the application of initial nominal concentrations (Guerin & Kennedy, 1992;Berrill et al 1998;DeLorenzo et al 1999). In addition, according to Laabs et al (2007), small microscosm systems ( < 1 L) have a low surface/volume ratio that favors endosulfan hydrolysis and losses by edge effects, fact also observed previously in the studies of Flemer et al (1995) and Barry & Logan (1998).…”

Acute toxicity and sublethal effects of the mixture glyphosate (Roundup® Active) and Cosmo-Flux®411F to anuran embryos and tadpoles of four Colombian species

“…This is consistent with Edginton et al (2004), who found that embryos (Gosner stage eight) of Xenopus laevis, Bufo americanus, Rana clamitans and Rana pipiens exposed to glyphosate formulated vision ® were less sensitive than larvae (Gosner stage 25). The greater sensitivity to pesticides of larval stage as compared with the embryonic stage of amphibians has been also reported by Hall and Swineford (1980), Berrill et al (1993), Berrill, Bertram, McGillivary, Kolohon and Pauli (1994), Berrill, Coulson, McGillivary and Pauli (1998), Edginton et al (2004). Surfactants have been demonstrated to cause lysis of gill epithelial cells in the rainbow trout (Partearroyo, Pilling, & Jones, 1991), and affect the ability of the gills to maintain osmotic balance.…”

Use of the microorganism Bacillus stearothermophilus as a model to evaluate toxicity of the lipophilic environmental pollutant endosulfan

“…Endosulfan, a mixture of a-and b-isomers, is a broad-spectrum insecticide, acaricide and miticide used to control a variety of pests that affect fruit, vegetables and ornamental plants (Berrill et al, 1998). This formulation with two isomers with different water solubilities and volatilities (Antonious et al, 1998) has been studied for its toxicity to aquatic organisms possibly affected by direct applications or drift from aerial spraying (Ernst et al, 1991;Berrill et al, 1998). Accumulated data concerning the toxicity hazard of endosulfan led to the recommendation that it should be replaced by less toxic alternatives wherever possible (Berril et al, 1998).…”