The British Herpetological Society

The Herpetological Journal is the Society's prestigious quarterly scientific journal. Articles are listed in Biological Abstracts, Current Awareness in Biological Sciences,Current Contents, Science Citation Index, and Zoological Record.

The 2017/18  impact factor of the Herpetological Journal is 1.268

  pdfBHS Ethics Policy

Download Access:

  • The latest 20 issues can be downloaded when logged in with a Herpetological Journal subscription membership.
  • Individual articles can be purchased for download.
  • Older issues and occasional Open Access articles are available for public download

pdf 03. Effects of four types of pesticides on survival, time and size to metamorphosis of two species of tadpoles (Rhinella and Physalaemus centralis) from the southern Amazon, Brazil

99 downloads

Open Access

Authors: Figueiredo, Jaime & de Jesus Rodrigues, Domingos

Abstract: Pesticides have been implicated as one of the main factors responsible for amphibian population declines. Although Brazil is one of the countries that harbours the largest diversity of amphibians on the planet and is a leader in the use of pesticides, few studies have addressed the effects of these substances on amphibians in Brazil. We evaluated the effect of four herbicides (glyphosate, 2,4-D, picloram and a picloram and 2,4-D mixture) commonly used in the southern Amazon on tadpoles of Rhinella marina and Physalaemus centralis. To address the acute toxicity of each pesticide, we calculated LC5096 values and compared them with values reported for several fish species provide by manufacturers, which are often used to infer toxicity of pesticides in Brazil. To address the chronic effects of each pesticide, we maintained tadpoles from Gosner stage 25 until stage 42 or metmorphosis and tested how fractions of LC5096 (25%, 50%, and 75% of LC5096) affected survival, time to metamorphosis and size of metamorphs of the tadpoles. Picloram and the mixture of picloram and 2,4-D showed the highest acute toxicity (LC5096) among the pesticides tested, with a much higher value than those reported for fish. Survival was affected by different concentrations depending on the type of pesticide, without a standard for chronic toxicity. The time to metamorphosis was reduced only in P. centralis, with 2,4-D at 25 and 50% of the LC5096 concentration. Therefore, with the other pesticides, the tadpoles were not able to accelerate their metamorphosis. The size of the metamorphs was increased or reduced depending on the concentration of the pesticide and the species, and in some cases, it was intermediate concentrations that had the greatest effect. These results indicate the need to reassess the current methods of estimating environmental risk because the effects on amphibian fauna are drastic and there is great expansion of agriculture areas in the Amazon.

Keywords: ECOTOXICOLOGY, PESTICIDES, TADPOLES, AMAZON, AMPHIBIAN

Submissions:

For further information and submission guidelines please see our Journal Instructions to Authors

 

 

NOTE: as of January 2017, all new editions of the HJ are ONLY available online via the BHS website. The BHS no longer has a commercial hosting agreement with Ingenta  -  although editions prior to end 2016 remain accessible on Ingenta .  Those editions are of course also accessible on the BHS website for subscribers with an active and valid membership.  Should you experience any difficulty accessing HJ editions via the website or have any queries in this regard, please contact