# LD50

All data in the table that follows must be viewed with grave suspicion. The Mouse LD50 is a figure that is indicative of a dosage that will kill 50% of the mice envenomated within 24 hours. These are standard 20 g mice. Thus a simple calculation involving yield and LD50 SHOULD be indicative of how many mice such a snake is capable of killing and by very crude approximation the weight of a human it would kill.

Example:
Dendroaspis polylepis (Black Mamba) has a LD50 (subcutaneous) of 0.32 mg/kg and a yield of 50.0 - 120.0 mg of venom. This means that it takes 0.32mg of venom to kill 500 grammes, of mice (remember it only kills half of those it is administered to). We use a standard 20g mouse, thus there are 50 mice to a kilogramme or 25 mice to 500 grammes. 1 mg of venom is enough to kill 78.125 mice. That is 1 divided by 0.32 and the result multiplied by 25. The snake yields up to 120 mg of venom so we multiply our result by 120 and arrive at a figure of 9375 mice. Or, by extrapolation, 187.5 kg of human(s). We do know from reliable records that this snake has killed 11 adult humans in a single attack. Thus the mouse LD50 obviously does not tell the whole story! It is however a baseline comparison that has some merits.

Mice are not humans. The testing has been done in various places where standards differ from laboratory to laboratory. Some data comes from snakes that were not - or cannot - be reconciled with an actual species.

The only figure of real interest is the subcutaneous LD50 as few snakes can ever achieve anything other than that. Some of the larger adders may penetrate deep enough to inject their venom intramuscularly and in a very unlucky few cases an intravenous injection may occur. Intraperitoneal envenomation is highly unlikely outside of the laboratory.

Venom yields are an average range for a "standard" snake of the species.

Snake venoms vary within species and can be influenced by age of snake, size and locality. Some are more effective against actual prey species than others. Lethality is really a function of the potency of the venom and the amount injected during a bite. The yields given here were achieved by actual milking and there is no indication that the snake will inject all the venom in a single bite.

Acknowledgements:
Data was obtained from a number of sources - most notably the Australian Venom and Toxin database and Dangerous Snakes of Africa by Stephen Spawls and Bill Branch.

## LD50 Scores for various snakes

Species Common name Sub-
cutaneous
mg/kg
Intra-
muscular
mg/kg
Intra-
venous
mg/kg
Intra-
peritoneal
mg/kg
Venom
Yield
mg
Acalyptophis peroni sea snake species 0.079
Acanthophis antarcticus Common death adder 0.5   0.25   70.0-236.0
Agkistrodon bilineatus taylori Ornate cantil     2.4 2.3
Agkistrodon bilineatus Cantil     2.4 1.155 50.0-95.0
Agkistrodon contortrix contortrix Southern copperhead 25.6   10.9 10.9 40.0-75.0
Agkistrodon contortrix mokasen Northern copperhead     2.7 4.222
Agkistrodon piscivorus leucostoma Western cottonmouth     2.044 4.844
Agkistrodon piscovorus Cottomouth/ Water moccasin 25.8   4 5.1 80.0-170.0
Aipysurus duboisi Dubois's sea snake 0.044       0.07
Aipysurus eydouxi Spine-tailed sea snake     4
Aipysurus laevis Olive sea snake 0.264 0.09     10.0-33.0
Atractaspis dahomeyensis Mole viper     2.24   1.3-7.6
Atropoides nummifer Jumping viper     2.4
Atropoides picadoi Central American pitviper species     1.6
Austrelaps superbus Lowland copperhead 0.5     0.28
Bitis arietans Puff adder   2 1.32   100.0-350.0
Bitis caudalis Horned adder     1.2   85
Bitis gabonica Gaboon viper 12.5 5.2 6.722 1.589 450.0-600.0
Bitis nasicornis Rhinoceros viper   8.6 1.1   200
Bothriechis schlegeli Eyelash viper 33.2   1.6   10.0-20.0
Bothrops alternatus Urutu 15.8   1.96   60.0-100.0
Bothrops asper Terciopelo     1.244 2.844 100.0.-310.0
Bothrops atrox Barba amarilla 22   2.835 3.8 100.0-200.0
Bothrops colombiensis South American pitviper species     2.3
Bothrops jararaca Jararaca 7   1.1   40.0-70.0
Bothrops jararacussu Jararacussu 13   0.46   200.0-321.0
Bothrops neuwiedi Jararaca pintada 14.2   2.3
Boulengeria annulata Banded water cobra 0.143
Boulengeria christyi Congo water cobra 0.12
Bungarus caeruleus Indian krait 0.365   0.169 0.089 8.0-20.0
Bungarus fasciata Banded krait 3.6   1.289 1.55 20.0-114.0
Bungarus multicinctus Many banded krait 0.108   0.113 0.08
Calloselasma rhodostoma Malayan pit viper 23.4   5.2 4.9885 40.0-60.0
Causus rhombeatus Night adder 15   8.75   300.0
Cerastes cerastes Sahara horned viper 15   0.5 0.3 20.0-70.0
Cerastes cornutus Desert horned viper     5.05
Cerastes vipera Sahara sand viper     0.64 0.25
Crotalus adamanteus Eastern diamondback rattlesnake 14.6   1.65 2.295 200.0-850.0
Crotalus atrox Western diamondback rattlesnake 18.5 20 2.72 5.588 175.0-600.0
Crotalus basiliscus Mexican west-coast rattlesnake 2.8
Crotalus catalinensis rattlesnake species   10.9   4.1
Crotalus cerastes Sidewinder       4 18.0-50.0
Crotalus durissus durissus Neotropical rattlesnake     1.244 0.667 20.0-100.0
Crotalus durissus terrificus Cascabel     0.262 0.216
Crotalus durissus totonacus rattlesnake species       2.5
Crotalus enyo enyo Orange rattlesnake   4.6
Crotalus exul rattlesnake species 9.92 9.2 2.17 3.9
Crotalus horridus horridus Timber rattlesnake 3.1   2.107 2.272 75.0-210.0
Crotalus intermedius rattlesnake species     1.58
Crotalus lepidus klauberi Rock rattlesnake 23.95   9   129.0
Crotalus mitchelli mitchelli Desert speckled rattlesnake   0.3   0.18
Crotalus mitchelli pyrrhus Southwestern speckled rattlesnake   9.6   2.7
Crotalus polystictus Mexican blotched rattlesnake 13.3   3.37
Crotalus pricei pricei Twin-spotted rattlesnake   11.5 3.07   4.0-8.0
Crotalus scutulatus salvini Huamantlan rattlesnake     0.24
Crotalus scutulatus scutulatus Mojave green rattlesnake     0.189 0.159 50.0-150
Crotalus tigris Tiger rattlesnake 0.21   0.056   6.0-11.0
Crotalus viridis caliginsis rattlesnake species       2.26
Crotalus viridis concolor Midget faded rattlesnake     0.0825 0.2
Crotalus viridis helleri Southern Pacific rattlesnake     1.135 2.44
Crotalus viridis lutosus Great basin rattlesnake       2.2
Crotalus viridis viridis Prarie rattlesnake     1.01 2 35.0-250.0
Crotalus willardi willardi Ridge-nosed rattlesnake     1.61
Cryptophis nigrescens Small eyed snake 2.67
Daboia russelii formosensis Russel's viper subspecies 1.37   0.4 0.489
Daboia russelli russelli Russell's viper species 0.75   0.133 0.4
Daboia russelli siamensis Russell' viper subspecies     2.11
Deinagkistrodon acutus Sharp-nosed pit viper 9.2   0.38
Demansia olivacea Olive whip snake 714.2
Dendroaspis angusticeps Eastern green mamba 3.05   1.3 0.117 60.0-95.0
Dendroaspis jamesoni Jameson's mamba 1   0.72 0.414
Dendroaspis polylepis Black mamba 0.32   0.25 0.941 50.0-120.0
Dendroaspis viridis Western green mamba 0.7   0.8 0.33 100
Dispholidus typus Boomslang     0.72   1.6-8.0
Echis carinatus multisquamatus (Iran) Saw-scaled viper     3.26
Echis carinatus sochureki(Pakistan) Saw-scaled viper     2.98
Echis carinatus Saw-scaled viper 0.151     2.15 5.0-48.0
Echis coloratus Carpet viper     0.575 0.263
Echis ocellatus (Nigeria) Saw-scaled viper     2.71
Echis pyramidium (Egypt) Saw-scaled viper     0.65
Echis pyramidium (Kenya) Saw-scaled viper     0.94
Echis pyramidium (Saudi Arabian) Saw-scaled viper     1.67
Emydocephalus annulatus Turtle-headed sea snake 25
Enhydrina schistosa Beaked sea snake 0.1125   0.26 0.107 7.7-9.0
Eristicophis macmohoni Asian sand viper     7.5
Gloydius blomhoffi Mamushi 20
Gloydius halys Pallas' viper     9.75
Hemachatus haemachatus Rinkhals 2.65   1.5   80.0-120.0
Hoplocephalus stephensi Stephen's banded snake 1.36
Hydrophis belcheri sea snake species   0.155
Hydrophis cyanocinctus Annulated sea snake 0.464   0.456 0.24 5.0-8.0
Hydrophis elegans Elegant sea snake 0.26 0.21     9.0-24.0
Hydrophis fasciatus Banded small headed sea snake     0.175
Hydrophis klossi sea snake species       0.365
Hydrophis major Olive-headed sea snake 0.193
Hydrophis melanosoma Black banded sea snake 0.111 0.082   0.4
Hydrophis nigrocinctus Duadin's sea snake 0.343
Hydrophis ornatus Reef sea snake   0.12 2.2
Hydrophis spiralis Yellow sea snake       0.315
Hydrophis stricticollis sea snake species 0.164
Kerilia jerdoni Jerdon's sea snake       0.53
Lachesis muta Bushmaster 36.9   4.51 6.17 200.0-500.0
Lapemis hardwicki Hardwicke's sea snake 0.541   0.8 0.26
Laticauda colubrina Banded sea krait 0.435   0.4
Laticauda laticauda Banded sea krait     0.163
Laticauda semifasciata Broad banded sea krait 0.273   0.34   2.0-14.0
Macrovipera lebetina Levantine viper 16   0.8
Micrurus alleni coral snake species     0.74 0.705
Micrurus annulatus hertwigi coral snake species     1.76 0.951
Micrurus dumarillii coral snake species     1.02 0.96
Micrurus frontalis frontalis Southern coral snake       0.592 20.0-30.0
Micrurus fulvius coral snake sp. 1.3   0.3   3.0-5.0
Micrurus micrurus anomalus coral snake species       0.118
Micrurus nigrocinctus Black banded coral snake     0.394 0.701 5.0-8.0
Micrurus spixi obscurus Amazonian coral snake subspecies       1.16
Naja atra Chinese cobra 0.29   0.345
Naja haje Egyptian cobra 1.15   0.96 0.185 175.0-300.0
Naja kaouthia Monocled cobra     0.373 0.225
Naja melanoleuca Forest cobra     0.6 0.324 500
Naja naja Spectacled cobra 0.45   0.35 0.315
Naja nigricollis Black necked spitting cobra   0.44 1.15 0.4 200.0-350.0
Naja nivea Cape cobra 0.72   0.57 0.4
Naja oxiana Central Asian cobra     0.96
Naja pallida Red spitting cobra       2
Notechis a. niger Peninsula tiger snake 0.131
Notechis a. occidentalis Western tiger snake 0.194
Notechis a. serventyi Chapel island tiger snake 0.338
Notechis scutulatus Mainland tiger snake 0.214   0.04   35.0-189.0
Ophiophagus hannah King cobra 1.7   1.31 1.644 350.0-500.0
Oxyuranus microlepidotus Inland taipan 0.025       44.0-110.0
Oxyuranus scutellatus Coastal taipan 0.106   0.013 0.009 120.0-400.0
Pelamis platurus Yellow bellied sea snake 0.067   0.22   1.0-4.0
Porthidium nasuta Hognosed viper     4.6   12.0-25.0
Praescutata viperina Viperine sea snake     4.5
Pseudechis australis Mulga snake 1.94   0.3
Pseudechis colletti Collett's snake 2.38     0.84
Pseudechis guttatus Spotted black snake 2.13
Pseudechis papuanus Papuan black snake 1.09
Pseudechis porphyriacus Red-bellied black snake 2   0.54   30.0-50.0
Pseudocerastes fieldi Field's horned viper     0.275 0.02
Pseudocerastes persicus Persian horned viper     15.26 1.0
Pseudonaja affinis Dugite 0.66
Pseudonaja nuchalis Gwardar/Western brown snake 0.473
Pseudonaja textilis Eastern brown snake 0.0365   0.01
Rhabdophis subminiatus Red-necked keeled snake     1.29
Sistrurus miliarius barbouri Red pygmy rattlesnake 24.3   12.59 6.822 12.0-35.0
Thelotornis kirtlandi Vine or Twig snake     1.01
Trimeresurus albolabris White lipped tree viper 12.75   0.37   8.0-15.0
Trimeresurus elegans Sakishima habu     5.225
Trimeresurus flavoviridis Okinawa habu     3.689 5.07
Trimeresurus gramineus Indian green tree viper 8.6
Trimeresurus macrosquamatus Chinese habu     5.225
Trimeresurus okinavensis Himehabu     3 15
Trimeresurus stejnegeri Chinese green tree viper     5.225
Tropidolaemus wagleri Wagler's viper 6.19   0.7833 3.58 65.0-90.0
Vipera ammodytes Long-nosed viper 6.59   0.8 0.415
Vipera aspis Asp viper   4.7 1   9.0-10.0
Vipera berus Adder 6.45   0.55   10.0-18.0
Vipera bornmuelleri True viper species 6.25   0.605 1.92
Vipera latifi True viper species 4.61   0.348 2.07
Vipera palaestinae Palestine viper 9.4   0.3 1.9
Vipera xanthina Near east viper     6.7   8.0-18.0
Walterinnesia aegyptia Desert cobra 0.4   0.48 0.133

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Copyright: Séan Thomas & Eugene Griessel - Dec 1999.