tag:blogger.com,1999:blog-3244394520661898405.post7864990776293555433..comments2023-06-26T06:21:26.689-05:00Comments on Serpent Research: Is DEET Toxic to Anacondas?John C. Murphyhttp://www.blogger.com/profile/06024060563494957012noreply@blogger.comBlogger5125tag:blogger.com,1999:blog-3244394520661898405.post-20750451481695164562013-01-19T16:59:23.162-06:002013-01-19T16:59:23.162-06:00"Amphibians, such as snakes and frogs..."..."Amphibians, such as snakes and frogs..."<br /><br />Snakes aren't amphibians; they're reptiles.arabiantealeaveshttps://www.blogger.com/profile/12788403741241604976noreply@blogger.comtag:blogger.com,1999:blog-3244394520661898405.post-49032443517652795762011-08-01T09:23:57.437-05:002011-08-01T09:23:57.437-05:00As a reptile ecotoxicologist, Id like to point out...As a reptile ecotoxicologist, Id like to point out that we are finding that so-called "new generation" insecticides can be VERY toxic to reptiles while having little toxicity to birds and mammals (e.g. pyrethroids). This is in large part due to newer insecticides being designed so that they are not toxic to organisms with high metabolism (i.e. birds and mammals). However, snakes and amphibians having lower metabolism are often more susceptible. <br /><br />A good example:<br /><br />Brooks et al. 1998. The oral and dermal toxicity of selected chemicals to brown tree snakes (Boiga irregularis). Wildlife Research 25: 427-435.<br /><br />I realize DEET is not, in reality, an insecticide, Im just pointing out that some chemicals that are considered "safe" can be quite toxic to organisms other than birds, mammals, and fish (who receive a majority of the ecotoxicology research).<br /><br />That said, Im skeptical as well. It is unlikely that DEET is killing off anacondas at environmentally relevant concentrations, however we need more data on reptiles to confirm this. A study on xenopus tadpoles doesnt really put my mind at rest (as xenopus are somewhat notorious for being more tolerant than other amphibian species). Also interspecies variability is huge in all taxa. I have found rotenone LD50s that range form 113 to 5000 ppm for various bird species. I was also unable to find that published study (Harada et al. 2008) given only the first authors last name and year. <br /><br />At low concentrations DEET (along with other anthropogenic PPCPs) could be causing endocrine disrupting effects, but I dont think it would be causing a short term mass die off.Scott W.noreply@blogger.comtag:blogger.com,1999:blog-3244394520661898405.post-19778615916960740652010-12-30T09:23:03.906-06:002010-12-30T09:23:03.906-06:00I took the time to write them a comment when i fir...I took the time to write them a comment when i first came across that article. It was done on their website, so I do not have a copy of it. Here is the response I got, and my response to the response:<br /><br />That article was so full of inaccuracies, it should be retracted and rewritten. Its no wonder that it was not attributed to an author, as no one would want to take credit for putting in print something that wasnt fact checked at a grade school level. Fundamental biological errors are blatant, but how does that fair for the validity of the subject matter? Is DEET really a concern to snakes? <br /><br />Pass this link along, to whomever penned that "article" : <br /><br /><br /><br />http://squamates.blogspot.com/2010/12/is-deet-toxic-to-anacondas.html<br /><br /><br /><br />I still find no substantiated claims that ANYTHING in your news clipping is correct. Maybe the tour guides name. Maybe.<br /><br /><br /><br /><br /><br />- Rob<br /> <br /><br /><br />--------------------------------------------------------------------------------<br />From: telegraphenquiries@telegraph.co.uk<br />To: -_@hotmail.com<br />Subject: Telegraph Reference: 678135<br />Date: Wed, 29 Dec 2010 10:19:37 +0000<br /><br /><br /> <br /><br /> <br /><br /> <br /><br /> <br /><br /> <br /><br /> <br /><br /> <br /><br /> <br /><br />29 December 2010<br /><br /> <br /><br />Dear Mr -,<br /><br /> <br /><br />Thank you for taking the time and trouble to write to the Telegraph and please accept my apologies for the delay in responding to you.<br /><br /> <br /><br />Your comments concerning how a snake breathes has been forwarded on to our editorial team for their reference and future knowledge when writing on the subject in the future.<br /><br /> <br /><br />We value your readership and appreciate your comments.<br /><br /> <br /><br />Yours sincerely<br /><br /> <br /><br />Andy King<br /><br />Editorial Information ExecutiveAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-3244394520661898405.post-60434743411809265542010-12-28T12:47:42.057-06:002010-12-28T12:47:42.057-06:00Here's what the toxicologist said:
Certainly,...Here's what the toxicologist said:<br /><br />Certainly, John C. Murphy’s point of view in the blog linked below referring to the article in The Telegraph is one with which I would agree:<br /><br />“…I have no doubt DEET is toxic to snakes at some level. However, it is difficult for me to believe that it is killing anacondas in the concentrations that it would be exposed to from being used by tourists. It seems to me an other [sic] cause of the snake mortality will be found once it is investigated. JCM”<br /><br />Interestingly, Roberto Justiniano, an Amazon basin (Yacuma River in northern Bolivia) tour guide and biologist states that “The high-strength insect repellant that tourists use to protect themselves from mosquitoes is absolutely fatal to the anacondas.” also is quoted in the The Telegraph article as saying, “They [anacondas] are amphibians and breathe through their skin.” In fact, anacondas are reptiles and breathe only through their lungs.<br /><br />Clearly, Mr. Justiniano is providing his opinion; however, he offers no data to support his contention that DEET is highly toxic to anacondas and as John C. Murphy points out in his blog, Google searches in Scholar (as well as comprehensive literature searches conducted by us) do not find articles that link DEET with toxicity in reptiles. A recently published study in an amphibian (which presumably would be more sensitive than reptiles because during early lifestages amphibians do “breathe water” with gills and their skin would be expected to be more permeable to an organic compound like DEET than skin of reptiles) using a standardized procedure called the Frog Embryo Teratogenesis Assay – Xenopus (Xenopus laevis), Harada et al. (2008) reported no effects at the highest concentration tested, 10 mg/L. To give this concentration perspective to levels of DEET reported in the environment, 10 mg/L is at least 1,000-fold greater than the DEET concentrations reported for surface waters in numerous published studies. Therefore, unless the Yacuma River is extremely polluted by insect repellents, it is not plausible that insect repellents, including DEET, are responsible for the high mortality among anacondas reported anecdotally for this region of Bolivia.<br /><br />Reference: Harada A, Komori K, Nakada N, Kitamura K, Suzuki Y. 2008. Biological effects of PPCPs on aquatic lives and evaluation of river waters affected by different wastewater treatment levels. Water Sci Technol 58: 1541-1546.gcstandhttps://www.blogger.com/profile/15599200196494901393noreply@blogger.comtag:blogger.com,1999:blog-3244394520661898405.post-68800622824069693232010-12-28T08:28:02.814-06:002010-12-28T08:28:02.814-06:00I work for the DEET Education Program. I spotted t...I work for the DEET Education Program. I spotted the same story YOU did and we are looking into it. I rather doubt this is true, but our toxicologists will have more information than I do. Reach me at DEETONLINE.org or 800-7898-3300. Soon as I have an answer, I'll let you know.gcstandhttps://www.blogger.com/profile/15599200196494901393noreply@blogger.com