Snake species can be both venomous or non-venomous. Poisonous snakes produce venom as a defense mechanism and for immobilizing prey. Snake venom gets its toxicity from the presence of zootoxins, which are injected into the victim through fang bites or spitting. The venom-producing glands are situated on either side of the snake’s head and are protected by a muscular sheath. Proteins constitute the largest elements in snake venom and cause the most damage in prey by inhibiting important enzymes. The toxicity of a snake‘s venom is expressed by murine LD50 test (lethal dose 50%). This test requires the use of other animals, mostly mice, which are injected with a dose of a particular snake’s venom. The trial aims to find out which snake venom can kill half of the animal’s population. The snakes with the lowest values are the most venomous. Australia has the bulk of the world’s poisonous snakes, where they mostly inhabit the country’s coastal region.
10. Western Australian Tiger Snake
The Western Australian tiger snake is one of Australia’s most venomous snakes. Its venom has a murine LD50 of 0.194 mg/kg. It inhabits swampy regions and wetlands and feeds on small mammals and birds.
9. Black Tiger Snake
The black tiger snake is an indigenous snake species of Australia. The snake exhibits variance in color mostly banded like those visible on a tiger. The tiger snake has a preference for coastal regions, creeks, and wetlands. It grows to a maximum of 10 feet, and it is ovoviviparous. The snake’s venom has a murine LD50 of 0.131 mg/kg, and it contains myotoxins, coagulants, neurotoxins, and hemolysins. The snake’s venom causes adverse effects in humans such as breathing difficulties, numbness, tingling sweating, and paralysis. When the tiger snake is disturbed, it flattens its body leaving its head raised ready to attack.
8. Black-banded Sea Krait
The black-banded sea krait inhabits the Pacific Ocean’s western warm waters, and its habitat range includes the eastern coast of Brunei and the Malay Peninsula and Halmahera, Indonesia. The snake comes up for air every six hours, and it has a preference for coral reefs. Its venom has a toxicity of 0.111 mg/kg when subjected to the subcutaneous injection LD50 test. The black-banded sea krait feeds on fish, and it rarely attacks humans, unless threatened. The Japanese refer to the snake as erabu umi hebi, and it is a winter delicacy in the southern part of the country.
7. Many-banded Krait
The Many-branded Krait’s habitat range includes Burma, Mainland China, Laos, Taiwan, and Vietnam. Its measure of LD50 of 0.108 mg/kg makes it earth’s seventh most venomous snake species. It is mostly observed in marshy regions as well as woodlands, plantations, mangroves, and shrublands. Its diet includes fish, snakes, frogs, lizards, rodents, and eels. The snake’s venom causes symptoms such as interrupted respiration, tunnel vision, diplopia, general ache, loss of voice, and discomfort in the chest region. The risk of death depends on the severity of the bite.
6. Coastal Taipan
The coastal taipan is a native snake species of Australia that inhabits the country’s eastern and northern coastal areas. It is among the world's most venomous terrestrial snakes with a murine LD50 of 0.099mg/kg. A fully mature coastal taipan is typically between 4.9 to 6.6 feet making it Australia’s longest venomous snake. Its venom is especially effective in hunting mammals such as rats and mice. The venom is fatal and affects the nervous system. An untreated victim will die within 2.5 hours of being bitten.
5. Peron's Sea Snake
Habitats of the Peron’s sea snake include the Strait of Taiwan, Gulf of Siam, Coral Sea islands, and other regions. Its venom reflects a value of 0.079 mg/kg when subjected to the subcutaneous injection LD50 test. The Peron’s sea snake is distinguished from other sea snakes by the spines on its head. Its average snout-vent length is 39 inches. It feeds on small fish and gives birth to its young ones, as opposed to laying eggs.
4. Yellow Bellied Sea Snake
The yellow-bellied sea snake is well established in earth’s tropical oceanic waters (with the exception of the Atlantic Ocean). It is characterized by a black back and a yellow underbelly. The murine LD50 of the snake’s venom is 0.067 mg/kg. The venom has fatal venom and affects the skeletal muscle. The venom can be neutralized by anti-venom. The yellow-bellied sea snake is fully adapted to marine habitats, and it feeds on fish species by swallowing them whole.
3. Eastern Brown Snake
The eastern brown snake is an indigenous species to Australia, Indonesia, and Papua New Guinea. It is characterized by different shades of brown, and its average length ranges between 3.6 to 5.9 feet. The snake’s diet consists of rodents while its habitat range includes grasslands, forests, savannah woodlands, and scrublands. The snake’s venom has a value of 0.053 mg/kg based on the subcutaneous injection LD50 test. In humans, the snake’s venom has effects such as renal failure, dizziness, convulsions, and diarrhea.
2. Dubois's Seasnake
The Dubois’ seasnake inhabits the coasts of the Coral, Timor, and Arafura Seas, and the Indian Ocean in Australia, Papua New Guinea, and New Caledonia. The venom of the snake has a toxicity level of 0.044 mg/kg when subjected to the subcutaneous injection LD50 test. Its prey is moray eels and other fish living on the sea floor. The Dubois’ seasnake ranks as the world’s second most poisonous sea snake.
1. Inland Taipan
The inland taipan inhabits the semi-arid parts of central east Australia. It achieves an average length of 5.9 feet with a maximum length of 8.2 feet. The inland taipan’s venom measures as the most toxic with a murine LD50 value of 0.025mg/kg. The low value means that the inland taipan needs a small dose of venom to paralyze prey. Its venom is estimated to be toxic enough to kill a minimum of 100 adult men. It preys on mammals but it is reclusive and shy, and thus bites are rarely reported by humans. Once bitten, an individual will experience localized pain followed by general feelings such as vomiting, diarrhea, dizziness, headache, convulsions, and abdominal pain. If left untreated, the victim succumbs to organ failure.