What is the most venomous snake in the world?
List of dangerous snakes
The South American bushmaster (Lachesis muta muta) is the longest species of venomous snake in the Western Hemisphere and the longest pit viper in the world. It is native to parts of South America, especially the equatorial forests east of the Andes. They are active at dusk or after dark and so they are very secretive and elusive. This species is large, fast and has a reputation for being particularly aggressive when cornered.[120][121] Some reports suggest that this species produces a large amount of venom that is weak compared to some other vipers.[122] Others, however, suggest that such conclusions may not be accurate. These animals are badly affected by stress and rarely live long in captivity. This makes it difficult to obtain venom in useful quantities and good condition for study purposes. For example, Bolaños (1972) observed that venom yield from his specimens fell from 233mg to 64mg while they remained in his care. As the stress of being milked regularly has this effect on venom yield, it is reasoned that it may also affect venom toxicity. This may explain the disparity described by Hardy and Haad (1998) between the low laboratory toxicity of the venom and the high mortality rate of bite victims.[123] However, wild specimens have an average venom yield per bite of 280–450mg (dry weight) (U.S. Dept. Navy, 1968). According to (Sanchez et al., 1992), who used wild specimens from Pará, Brazil, the average venom yield per bite was 324mg, with a range of 168–552mg (dry weight).[124] Brown (1973) gives the following LD50 values for mice: 1.5mg/kg IV, 1.6–6.2mg/kg IP, 6.0mg/kg SC. He also notes a venom yield of 200–411mg.[15] Human envenoming by this species, although infrequent, can be rather severe due to the large volumes of venom injected. Envenomation is characterized by pronounced local tissue damage and systemic dysfunctions, including massive internal bleeding.[125]