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Should hobbyists ever free handle venomous reptiles with their hands?
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Most venomous/toxic Naja species in the world? I have read that the Philippine cobra is the most venomous (mice, 0.2 mg/kg SC with the lowest reported value being 0.14 mg/kg SC) (Brown, 1973). I have recently, come across something in the Indian Journal of Experimental Biology (Vol. 30, (issue 12), pages: 1158-1162, 1992) which stated that the LD50 for Naja oxiana was the most toxic/venomous (mice, 0.18 mg/kg SC and lowest reported value was 0.10 mg/kg). Along with that, the mortality rate for untreated Naja oxiana bites are the highest among all Naja species (70-80%). N.oxiana also produced the lowest known lethal dose (LCLo) of 0.005 mg/kg, the lowest among all cobra species ever recorded, derived from an individual case of poisoning by intracerebroventricular injection.
Following N. oxiana and N. philippinensis are N. melanoleuca at 0.225 mg/kg SC and then N. samarensis at 0.23 mg/kg. The water cobras (N. annulata and N. christyi also have very toxic venoms, but no SC values are listed. Only intraperitoneal (IP) values of 0.143 mg/kg for N. annulata and 0.12 mg/kg for N. christyi. IP values tend to be generally lower (more toxic than subcutaneous values, so it would be unfair to compare their IP results to the subcutaneous (SC) results of other Naja species. Then I have heard that (without solid evidence) that Naja nivea is the most venomous, although their murine SC LD50 range anywhere from 0.4 mg/kg (Toxicon, Vol. 5, issue 1, page 47, 1967) to 0.72 mg/kg (Australian venoms and toxins Databse).
So which is the most venomous? To me it seems obvious that it is the Caspian or Oxus cobra (Naja oxiana), followed by the Philippine cobra (Naja philippinensis). What do you think or know?
I've noticed that the Australian venom and toxin Database seems to have higher LD50 values for all snakes across the board. For example, for the black mamba IP value of 0.01 mg/kg is listed (http://www.sciencedirect.com/science/article/pii/004101018890219X) and Ernst and Zug et al 1996, list a SC value of 0.05 mg/kg for the black mamba. While the Australian venom and toxin Database listed much less toxic LD50's. So there seems to be a lot of variation.
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Most venomous/toxic Naja species in the world? I have read that the Philippine cobra is the most venomous (mice, 0.2 mg/kg SC with the lowest reported value being 0.14 mg/kg SC) (Brown, 1973). I have recently, come across something in the Indian Journal of Experimental Biology (Vol. 30, (issue 12), pages: 1158-1162, 1992) which stated that the LD50 for Naja oxiana was the most toxic/venomous (mice, 0.18 mg/kg SC and lowest reported value was 0.10 mg/kg). Along with that, the mortality rate for untreated Naja oxiana bites are the highest among all Naja species (70-80%). N.oxiana also produced the lowest known lethal dose (LCLo) of 0.005 mg/kg, the lowest among all cobra species ever recorded, derived from an individual case of poisoning by intracerebroventricular injection.
Following N. oxiana and N. philippinensis are N. melanoleuca at 0.225 mg/kg SC and then N. samarensis at 0.23 mg/kg. The water cobras (N. annulata and N. christyi also have very toxic venoms, but no SC values are listed. Only intraperitoneal (IP) values of 0.143 mg/kg for N. annulata and 0.12 mg/kg for N. christyi. IP values tend to be generally lower (more toxic than subcutaneous values, so it would be unfair to compare their IP results to the subcutaneous (SC) results of other Naja species. Then I have heard that (without solid evidence) that Naja nivea is the most venomous, although their murine SC LD50 range anywhere from 0.4 mg/kg (Toxicon, Vol. 5, issue 1, page 47, 1967) to 0.72 mg/kg (Australian venoms and toxins Databse).
So which is the most venomous? To me it seems obvious that it is the Caspian or Oxus cobra (Naja oxiana), followed by the Philippine cobra (Naja philippinensis). What do you think or know?
I've noticed that the Australian venom and toxin Database seems to have higher LD50 values for all snakes across the board. For example, for the black mamba IP value of 0.01 mg/kg is listed (http://www.sciencedirect.com/science/article/pii/004101018890219X) and Ernst and Zug et al 1996, list a SC value of 0.05 mg/kg for the black mamba. While the Australian venom and toxin Database listed much less toxic LD50's. So there seems to be a lot of variation.
Posted: Jan 23, 2014
(51 votes, 6 comments)
by Mamba84
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Survey Results
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Naja melanoleuca
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8% (4)
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Naja samarensis
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0% (0)
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Naja oxiana
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45% (23)
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Naja philippinensis
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22% (11)
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Naja nivea
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18% (9)
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Naja annulata
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6% (3)
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Naja christyi
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2% (1)
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Survey Comments
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Naja venom toxicity
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There is perhaps some misunderstanding here. Broadly, Naja venoms can be subdivided into two groups: i) venoms of relatively low toxicity (African spitters) and ii) venoms of high toxicity (African and Asian nonspitters and most Asian spitters). It should be noted that the latter group owes essentially all of its lethality, be it in prey animals or humans, one group of venom toxins: the post-synaptically acting alpha-neurotoxins of the so-called three finger type (causing muscle paralysis). Now these toxins, if purified and analyzed isolated, i.e., not in the context of the whole-venom, typically have LD50s in mice of approximately 0.05-0.15 milligram per kilogram mice. Since, as mentioned above, these whole-venom components are the primary lethal factors, and co-operativity (the working-together) of different venom components does not seem to play a role in Naja venoms, these numbers thus set the limit for whole venom toxicity! More specifically, it is the proportion of the lethal component relative to the total dry mass of the whole-venom that determines the toxicity of a Naja venom. So if, for instance, an alpha-neurotoxin of, say, an LD50 of 0.1 milligram per kilogram mice makes up about 50% of the dry mass of a whole-venom, the LD50 of that Naja venom would amount to approximately 0.2 milligramm per kilogram mice, a value that is well within the range of the toxicity of the most venomous Naja species (including philippinensis, oxiana and annulata/christyi). However, it seems to be precisely the relative proportion of lethal venom component that is most variable EVEN WITHIN A SPECIES, in specimen from different localities. For example, although good-old Naja kaouthia venom has an LD50 of around 0.4 milligram per kilogram, recent findings have revealed that N. kaouthia from the Northeast of India have a venom that is at least twice as toxic and thus has an LD50 in the range of the most toxic Naja species mentionend above. So in sum, the question which Naja is the most venomous is not easy to answer and will be depend in part on species locality, but it is clear that, given that Naja venoms have been comparatively well studied, it is unlikely that there will be a major surprise with an LD50 below 0.1 milligram per kilogram.
Posted by
venomics
on November 11, 2014
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No question: Naja philippinensis followed by N.
nivea.
Posted by
Phobos
on August 18, 2014
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Toxic Venom
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I think the most powerful/toxic venom by
snake of he land is Inland Taipan
Speaking about Naja family i think the most
toxic venom is from the Cape Cobra, Indian
Cobra but also Egyptian Cobra ( Naja Haye)
About NeuroToxic venom Australian snakes like
Tiger Snake, Eastern and Coastal Taipan have
powerful venom ( also Papuan Taipan one of
the most dangerous snakes for byte in those
areas)
I also think about CytoToxic venom the most
dangerous is from Saw scaled viper from India
and Africa but also snakes like Malayan
PitViper and all rattlesnakes from USA
Posted by
RattleAbe
on April 16, 2014
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If your asking which species is the most toxic your post
statement answers it. Caspian cobra venom is reported
most toxic. I know of no other reports/ studies of venom
tests via injection directly into the brains of mice. I've
not found any abstracts for those studies either but the
info that I've read in those report do not state the age of
the mice in question. Age is a very valid variable that
must be taken into account. I suspect a day old pink
would have a different ld50 than an adult as their
anatomy is still developing. Dead is dead though. What's
the difference in toxicity between 1 and 2 mg/kg really?
Its 100% right, but dead is dead. I'm wondering if there's
really a practical reason to quantify venom toxicity other
than statistically speaking. It's not like people are being
medically injected with processed venom when they get
bit, non the less being injected into their brains!
Posted by
Online
on April 2, 2014
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Bryan fry might be the person to ask about
this, but from what I gather there tends to
be quite a bit that goes into this. When you
talk about LD50's its one thing. Then talking
about the level of danger to people its a
whole different beast of a conversation. It
also depends on if the bite is intravenous,
intramuscular, or just subcutaneous. This
would be a difficult question to answer
without the LD50's of all the above. Then you
also have to take into account the venom
yield of each animal. Depending on who you
ask the answers may vary.
Posted by
vanerka
on February 14, 2014
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most venomous cobra
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I would think snakes that have a fish diet
would probably have more potent or faster
acting venom because prey can get away
quicker???? It's just my guess. But then
nerodia (watersnakes) are not venomous and have
been surviving for thousands of years.
Posted by
choppergreg74
on January 30, 2014
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