FOOD: Poisonous snakes

MatC · 336855. Thu May 15, 2008 6:12 am

Q: Can you name a poisonous snake?

F: Cobra, rattlesnake, viper, adder, cottonmouth, mamba, boomslang, copperhead, etc. (NB: if anyone offers “garter snake,” SF should ask “Which garter snake?”)

A: There are two names you could have given me: Rhabdophis tigrinus (the Japanese grass snake), and Thamnophis sirtalis (common garter snake).

Notes:
Vipers, cobras and the rest aren’t poisonous - they’re venomous. Poison does you harm when you ingest it; venom does you harm when it’s injected into you. It’s “poisonous” when you bite it - it’s “venomous” when it bites you.

However, the Japanese grass snake becomes poisonous by eating toxic toads, which it is able to tolerate. It stores their poison in glands in its neck. When attacked, the snake
arches its neck, to make these glands prominent, so that any creature biting them will get poisoned. The neck, of course, is where predators usually bite snakes when trying to kill them.

The orange-bellied, rough-skinned newt is one of the most poisonous creatures on earth. A 29-year-old man in a bar in Oregon, in 1979, swallowed one for a bet. He was dead within hours, the prat. The only animal known to eat the newt is the common garter snake, some of which have evolved a tolerance to the toxin. This makes them deadly prey for, for instance, foxes which eat their livers. Which is bugger-all help to the snakes, of course.

Experts think there may well be more poisonous snakes, yet to be discovered.

Extra note:
Virtually all spiders are venomous - including the cute little spiders we know in this country. It’s just that most of them can’t puncture human skin to deliver their venom.

As far as is known, there are no poisonous spiders.

S:
http://www.nytimes.com/2007/01/30/science/30observ.html
http://www.scienceblog.com/cms/node/7478
http://community.seattletimes.nwsource.com/archive/?date=20030224&slug=newt24m
http://www.wildaboutbritain.co.uk/forums/insects/10951-spider-venomous.html
http://www.washington.edu/burkemuseum/spidermyth/myths/2marks.html

Picture: A close-up of dripping fangs?

MatC · 340767. Wed May 21, 2008 5:19 am

Cinnabar moth caterpillars have evolved to store the deadly ragwort alkaloid in their bodies, which they use as a defence against being eaten by birds; the caterpillars’ colours “advertise their borrowed toxins.”

S: “No nettles required” by Ken Thompson (Eden Project Books, 2006)

Jenny · 340962. Wed May 21, 2008 8:28 am

I know that cobras are venomous, not poisonous, but I can't resist bringing you, even while I shudder, this news item about a man who set a world record for kissing a cobra.