Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved venom apparatus, such as fangs or a stinger, in a process called envenomation. Venom is often distinguished from poison, which is a toxin that is passively delivered by being ingested, inhaled, or absorbed through the skin, and toxungen, which is actively transferred to the external surface of another animal via a physical delivery mechanism.
Elapidae is a family of snakes characterized by their permanently erect fangs at the front of the mouth. Most elapids are venomous, with the exception of the genus Emydocephalus. Many members of this family exhibit a threat display of rearing upwards while spreading out a neck flap. Elapids are endemic to tropical and subtropical regions around the world, with terrestrial forms in Asia, Australia, Africa, and the Americas and marine forms in the Pacific and Indian Oceans. Members of the family have a wide range of sizes, from the 18 cm (7.1 in) white-lipped snake to the 5.85 m king cobra. Most species have neurotoxic venom that is channeled by their hollow fangs, and some may contain other toxic components in various proportions. The family includes 55 genera with around 360 species and over 170 subspecies.
Acanthophis is a genus of elapid snakes. Commonly called death adders, they are native to Australia, New Guinea and nearby islands, and are among the most venomous snakes in the world. Despite their common name, they are not adders at all and belong to the Elapidae family. The name of the genus derives from the Ancient Greek akanthos/ἄκανθος ('spine') and ophis/ὄφις ('snake'), referring to the spine on the death adder's tail.
Taipans are snakes of the genus Oxyuranus in the elapid family. They are large, fast-moving, highly venomous, and endemic to Australia and New Guinea. Three species are recognised, one of which, the coastal taipan, has two subspecies. Taipans are some of the deadliest known snakes.
A snakebite is an injury caused by the bite of a snake, especially a venomous snake. A common sign of a bite from a venomous snake is the presence of two puncture wounds from the animal's fangs. Sometimes venom injection from the bite may occur. This may result in redness, swelling, and severe pain at the area, which may take up to an hour to appear. Vomiting, blurred vision, tingling of the limbs, and sweating may result. Most bites are on the hands, arms, or legs. Fear following a bite is common with symptoms of a racing heart and feeling faint. The venom may cause bleeding, kidney failure, a severe allergic reaction, tissue death around the bite, or breathing problems. Bites may result in the loss of a limb or other chronic problems or even death.
Snake venom is a highly toxic saliva containing zootoxins that facilitates in the immobilization and digestion of prey. This also provides defense against threats. Snake venom is injected by unique fangs during a bite, whereas some species are also able to spit venom.
Russell's viper is a venomous snake in the family Viperidae native to the Indian subcontinent and one of the big four snakes in India. It was described in 1797 by George Shaw and Frederick Polydore Nodder, and named after Patrick Russell, who wrote about it in his 1796 work An account of Indian serpents, collected on the coast of Coromandel.
The inland taipan, also commonly known as the western taipan, small-scaled snake, or fierce snake, is a species of extremely venomous snake in the family Elapidae. The species is endemic to semiarid regions of central east Australia. Aboriginal Australians living in those regions named the snake dandarabilla. It was formally described by Frederick McCoy in 1879 and then by William John Macleay in 1882, but for the next 90 years, it was a mystery to the scientific community; no further specimens were found, and virtually nothing was added to the knowledge of this species until its rediscovery in 1972.
The eastern brown snake, often referred to as the common brown snake, is a species of extremely venomous snake in the family Elapidae. The species is native to eastern and central Australia and southern New Guinea. It was first described by André Marie Constant Duméril, Gabriel Bibron, and Auguste Duméril in 1854. The adult eastern brown snake has a slender build and can grow to 2 m (7 ft) in length. The colour of its surface ranges from pale brown to black, while its underside is pale cream-yellow, often with orange or grey splotches. The eastern brown snake is found in most habitats except dense forests, often in farmland and on the outskirts of urban areas, as such places are populated by its main prey, the house mouse. The species is oviparous. The International Union for Conservation of Nature classifies the snake as a least-concern species, though its status in New Guinea is unclear.
Hydrophis belcheri, commonly known as the faint-banded sea snake or Belcher's sea snake, is an extremely venomous species of elapid sea snake. It has a timid temperament and would normally have to be subjected to severe mistreatment before biting. Usually those bitten are fishermen handling nets, although only one-quarter of those bitten are envenomated since the snake rarely injects much of its venom. Although not much is known about the venom of this species, its LD50 toxicity in mice has been determined to be 0.24 mg/kg when delivered intramuscularly.
The horned adder is a viper species. It is found in the arid region of southwest Africa, in Angola, Botswana, Namibia; South Africa, and Zimbabwe. It is easily distinguished by the presence of a single, large horn-like scale over each eye. No subspecies are currently recognized. Like all other vipers, it is venomous.
The tiger rattlesnake is a highly venomous pit viper species found in the southwestern United States and northwestern Mexico. No subspecies are currently recognized. The specific name tigris,, refers to the many narrow dorsal crossbands, which create a pattern of vertical stripes when viewed from the side.
The Central Ranges taipan, or Western Desert taipan, is a species of taipan that was described in 2007 by Australian researchers Paul Doughty, Brad Maryan, Stephen Donnellan, and Mark Hutchinson. Taipans are large, fast, extremely venomous Australasian snakes. The Central Ranges taipan was named one of the top-five new species of 2007 by the International Institute for Species Exploration at Arizona State University.
Aipysurus duboisii, also known commonly as Dubois' sea snake and the reef shallows sea snake, is a species of extremely venomous snake in the subfamily Hydrophiinae of the family Elapidae. Its geographic range includes Papua New Guinea, New Caledonia and the northern, eastern and western coastal areas of Australia, that is the Coral Sea, Arafura Sea, Timor Sea and Indian Ocean. It lives at depths up to 80 meters in coral reef flats, sandy and silty sediments which contain seaweed, invertebrates and corals or sponges that can serve as shelter. It preys upon moray eels and various fish that live on the seafloor, up to 110 cm in size. A. duboisii is viviparous, giving birth to live young rather than laying eggs. It displays medium aggressiveness, i.e., will bite if provoked, but not spontaneously. The fangs are 1.8 mm long, which are relatively short for a snake, and the venom yield is 0.43 mg. Aipysurus duboisii is a crepuscular species, meaning that it is most active at dawn and dusk.
The coastal taipan, or common taipan, is a species of extremely venomous snake in the family Elapidae. Described by Wilhelm Peters in 1867, the species is native to the coastal regions of northern and eastern Australia and the island of New Guinea. The second-longest venomous snake in Australia, the coastal taipan averages around 2.0 m (6.6 ft) long, with the longest specimens reaching 2.9 m (9.5 ft) in length. It has light olive or reddish-brown upperparts, with paler underparts. The snake is considered to be a least-concern species according to the International Union for Conservation of Nature.
Most snakebites are caused by non-venomous snakes. Of the roughly 3,700 known species of snake found worldwide, only 15% are considered dangerous to humans. Snakes are found on every continent except Antarctica. There are two major families of venomous snakes, Elapidae and Viperidae. 325 species in 61 genera are recognized in the family Elapidae and 224 species in 22 genera are recognized in the family Viperidae, In addition, the most diverse and widely distributed snake family, the colubrids, has approximately 700 venomous species, but only five genera—boomslangs, twig snakes, keelback snakes, green snakes, and slender snakes—have caused human fatalities.
Venom in snakes and some lizards is a form of saliva that has been modified into venom over its evolutionary history. In snakes, venom has evolved to kill or subdue prey, as well as to perform other diet-related functions. While snakes occasionally use their venom in self defense, this is not believed to have had a strong effect on venom evolution. The evolution of venom is thought to be responsible for the enormous expansion of snakes across the globe.
