|
1-3 of 3 messages
|
Page 1 of 1
|
|
venom #1usa
|
Reply
|
|
by elapidking81 on September 1, 2003
|
Mail this to a friend!
|
ok, i still dont under stand the ld 50 but i need to know drop for drop is the coral snake the most venomous snake in the us or is the mojave rattle snake i thought that it was the coral snake but the ld50 made it look like the mojave was please help
|
| |
|
RE: venom #1usa
|
Reply
|
|
by Ferdelance_1 on September 1, 2003
|
Mail this to a friend!
|
We all definitely know, (for a change), which serpent is the most dangerous. The Mojave Rattlesnake of course!
When it comes to venom toxicity that's not quite the case:
(1): Crotalus tigris: LD50 .21
(2): Crotalus scutulatus: LD50 .34
(3) Micrurus fulvius LD50 1.3
Cheers,
Derek K.
|
| |
|
Ld50
|
Reply
|
|
by TomT on September 1, 2003
|
Mail this to a friend!
|
I've broken this down in previous answers to this question, but I can't recall when it was, so I'll have a go at it again here.
LD50= the amount of venom injected into an animal, in which 50% of the animals that receive a given amount of that venom (or other toxin I suppose) receive a Lethal Dose (LD).
If you look at the LD50 chart for venomous snakes, it is important to understand that these figures are calculated on MICE, not MEN. It is fairly accurate to extrapolate the data to men, but it is not a 100% safe assumption that the most lethal venoms on mice will also be the most lethal to men.
The way the tests are conducted, at least the way I understand them to be conducted, an amount of venom is injected into a population of mice and if more than 50% of the mice survive you have not yet reached the threshold of your lethal dose in 50% of the population. The doses are measured in milligrams per kilogram (mg/kg) of body weight. It would probably be a little easier to understand if the values were in mg/*gram* of body weight, since the mice used only weight a few grams, but once you get used to thinking in terms of mg/kg the data is a bit easier to digest.
Let's assume (you know what happens when you assume something, right?), for a few minutes, that these are accurate values for lethal doses in men instead of mice. Using the data from Dr. Fry's LD50 chart, Dendroaspis jamesoni has an LD50 rating of 1 mg/kg when injected subcutaneously (under the skin). That means that for every 1 milligram of Jameson's Mamba venom, there is enough toxicity to kill 50% of all of the 1 kilogram mice in the world.... not a very effective way to try to figure out if the snake's bite will kill a man, but there haven't been any volunteers to try this out on humans yet...
Let's go a little farther... if that Mamba venom extrapolates to humans on a 1:1 (humor me) basis, then 1 mg. of Dendroaspis jamesoni venom would kill 50% of the 1kg. humans it bites. If I weigh 100 kilos, and the snake is capable of injecting 100 mg. in a bite, then I could be in SERIOUS trouble if I were bitten.
So, you have to look at more than just the potency of the venom. You have to look at yield of the venom as well. The most potent venom is not as worrisome as something less toxic (look at Crotalus atrox as an example) that can produce massive quantites of the stuff and who has a track record, if you will, of not being shy about dosing it out...
Last comparison... think in terms of Derek's example of Crotalus tigris it's LD50 (subQ) is 0.21mg/kg WOW!! Right??? Not when you consider that it's yeild is extremely small... something on the order of 8-10 milligrams.... now consider the Western Diamondback whose LD50 is a whopping 18.5 mgs/kg.... a real wimp, until you take the fact into consideration that an adult C.atrox can produce over 100 mgs. of the stuff...
Perhaps this is a little clearer to you now than before? It isn't so much about how "strong" the venom is, but a combination of factors... how potent, how much, and how likely are you to take a bite deep into muscle tissue or into a vein.... give me a C. tigris bite over a C.atrox bite anyday..... better yet, I'll just pass on anymore bites... I've had all I want.
TomT
|
| |
|
Email Subscription
You are not subscribed to this topic.
Subscribe!
My Subscriptions
Subscriptions Help
Check our help page for help using
, or send questions, comments, or suggestions to the
Manager.
|
