Robert C. Jadin

 

Venomous vs. Poisonous

by 

Robert C. Jadin

    People often ask what the difference between venomous and poisonous.  They ask why I tell them not to call a snake poisonous.  Well technically all venoms are a poison however not all poisons are venoms.  Too many times people get confused because someone on television says that a snake is poisonous while another says venomous.  So to make things simple I will explain it.  Any type of animal that injects a toxin into your body is venomous.  If you touch or ingest a toxin from a plant or animal and become sick then it is poisonous.  Snakes that inject toxins from fangs and the two species of Helodermatid lizards are venomous while plants, amphibians, and fungi (mushrooms) are all poisonous.  There are varying types of poisons and venoms that I won't get into a lot of detail with.  Some snake venoms are designed to destroy blood and tissue cells (Hemotoxins) while others are designed to cause nerve damage (Neurotoxin).  Some amphibians such as salamanders have toxins that are harmful if you touch or swallow them.  The Rough-skinned Newt has a toxin found throughout its body called Tarichotoxin which is a type of tetrodotoxin.  Tetrodotoxin is a toxin made famous by the Japanese Puffer Fish dish, Fugu, where if it isn't cooked just right you can die from eating it.  There is an article I read a few years back, in I believe the book Amphibians and Reptiles of the Pacific Northwest, where a college student from Oregon got dared to swallow a Rough-skinned Newt and he ended up dying a couple hours later.  This story inspired me to catch some of these newts so I found some in Washington state.  I have photos in the summer of 2001.  

     I am sure that all amphibians are poisonous since they all have granular glands in their skin.  I haven't heard of any amphibians that aren't poisonous so if you handle any make sure you wash your hands afterwards.  If you got some toxins from a Taricha sp. or some poison dart frog and got that in your eye or mouth you could end up in the hospital.  Most toads of course have paratoid glands, which are highly condensed toxin glands at the tops of their heads, as well as granular glands.  My teacher Dr. Cobb told a story to our class about a herpetologist who was licking salamanders by a creek bed to find differences in taste.  His students apparently found him passed out on the side of the creek.  Probably pretty embarrassing for a university professor. 

     There is a difference between venoms and poisons.  I have read that a person can swallow snake venom without feeling any ill effects.  As long as your mouth and throat have no sores or open wounds you should be fine.  However, if you swallow a poison you will become poisoned.  So scientifically speaking it is proper to say that there are venomous snakes not poisonous snakes.   

 

Bibliography

      The Merck Index

      Medical Herpetology by Steve Grenard

      Herpetology by Zug, Caldwell, and Vitt


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