Finding a Myth Inside an Article from ScienceDaily.com

I was reading through several recent articles about herps online and stumbled across a new article on ScienceDaily.com (http://www.sciencedaily.com/releases/2012/04/120416154051.htm) that discussed how the warm and wet weather the U.S. has had this year has lead to a proliferation of venomous snakes in Texas.  The article reports a higher than usual number of people bringing their pets in to treat snake bites.  The purpose of this article was to warn readers to be vigilant while outside, in the woods, and etc. in order to avoid the costly medical bills often associated with snake bites (a venomous bite + antivenin + tissue repair treatments + extended hospitalization = ~$50,000!).  This article then goes on to talk about how snakes are generally more afraid of us then we are of them, what to look for if you suspect your pet has been bitten, and etc.  This is all well and good until the author implied to pay special attention to smaller venomous snakes because "larger snakes tend to have lesser amounts of venom than smaller ones".

This made no sense to me.  I figured it might make some sense that smaller snakes have slightly more potent venom than their larger counterparts, perhaps to make up for the lack of volume.  But smaller snakes producing MORE venom?  I decided to investigate this further.  Here is what I found...

Volume of Venom

The volume of venom in a snake’s venom gland has been found to increase exponentially with the size of the snake, and can range from 1 – 850ml (or more). (Source: http://ufwildlife.ifas.ufl.edu/venomous_snake_faqs.shtml; http://www.llu.edu/behavioral-health/ebs/hayes/research-a-snake-venom.page)

In addition, larger snakes have larger fangs, which would allow deeper penetration of venom with increased venom flow.

 Hayes (1991) Toxicon 29:867-875

Potency of Venom

Researchers have shown that younger rattlesnakes often had stronger venom than their older counterparts.  In addition, Tun-Pe et al. (1995) showed that younger Russell's viper snakes possessed higher lethal activity and possessed more potent coagulating and defibrinogenating activities than adults. In some species, it has also been shown that younger individuals had more neurotoxins in their venom (Calvete et al., 2010).  However, more current research suggests their is a wide range of venom potency among individuals--young or old (http://www.ces.ncsu.edu/gaston/Pests/reptiles/venomousnake.htm) 

In summary, research shows that smaller snakes do not produce a greater volume of venom compared to larger snakes.  Perhaps the author meant to suggest that smaller, younger snakes may produce more potent venom than their mature counterparts, which has been shown to be possible!

Literature Cited

Calvete JJ, Sanz L, Cid P, De La Torre P, Flores-Diaz M, Dos Santos MC, Borges A, Bremo A, Angulo Y, Lomonte B, Alape-Giron A, Gutiérrez JM. 2010. Snake venomics of the Central American rattlesnake Crotalus simus and the South American Crotalus durissus complex points to neurotoxicity as an adaptive paedomorphic trend along Crotalus dispersal in South America. J Proteome Res 9:528–44.

Tun-Pe, Nu-Nu-Lwin, Aye-Aye-Myint, Kyi-May-Htwe, and Khin-Aung-Cho. 1995. Biochemical and biological properties of the venom from Russell's viper (Daboia russelli siamensis) venoms of varying ages. Toxicon 33:817-821.