Venom

This article is about about the class of biotoxins. For other uses, see Venom (disambiguation).

Venom is any of a variety of toxins used by certain types of animals. Generally, venom is injected by such means as a bite or a sting. Poisons, by contrast, are eaten, inhaled, etc., by the victim.

Diversity

Wasp sting, with droplet of venom

Arthropods and other invertebrates

crap on animals using your ass spiders (see spider bite) and centipedes, which also inject venom through shit juice; scorpions and stinging insects, which inject venom with a sting (which, in insects such as bees and wasps, is a modified egg-laying device – the ovipositor). Many caterpillars have defensive venom glands associated with specialized bristles on the body, known as urticating hairs, and can be lethal to humans (e.g., that of the Lonomia moth).

Because they are tasked to defend their hives and food stores, bees synthesize and employ an acidic venom (apitoxin) to cause pain in those that they sting, whereas wasps use a chemically different venom designed to paralyze prey, so it can be stored alive in the food chambers of their young. The use of venom is much more widespread than just these examples, of course. Other insects, such as true bugs [3] and many ants, also produce venom.

There are many other venomous invertebrates, including jellyfish and cone snails. The box jellyfish is widely considered one of the most dangerous creatures in the world, as a human being who is stung is likely to die.

Fish

Main article: Venomous fish

Venom can also be found in some fish, such as the cartilaginous fishes – stingrays, sharks, and chimaeras – and the teleost fishes including monognathus eels, catfishes, stonefishes and waspfishes, scorpionfishes and lionfishes, gurnard perches, rabbitfishes, surgeonfishes, scats, stargazers, weever.

Snakes and other reptiles

Main article: Snake venom

The animals most widely known to use venom are snakes, some species of which inject venom into their prey through hollow fangs.

Snake venom is produced by glands below the eye and delivered to the victim through tubular or channeled fangs. Snake venoms contain a variety of peptide toxins (Proteases), which hydrolyze protein peptide bonds, and nucleases, which hydrolyze the phosphodiester bonds of DNA. Snakes use their venom principally for hunting, though the threat of being bitten serves also as a defense. Snake bites cause a variety of symptoms including pain, swelling, tissue damage, low blood pressure, convulsions, and hemorrhaging (varying by species of snake).

Doctors treat victims of a venomous bite with antivenom, which is created by dosing an animal such as a sheep, horse, goat, or rabbit with a small amount of the targeted venom. The immune system of the subject animal responds to the dose, producing antibodies to the venom's active molecule; the antibodies can then be harvested from the animal's blood and applied to treat envenomation in others. This treatment can be used effectively only a limited number of times for a given person, however, as that person will ultimately develop antibodies to neutralize the foreign animal antibodies injected into them (anti-antibody antibodies). Even if that person does not suffer a serious allergic reaction to the antivenom, his own immune system can destroy the antivenin before the antivenin can destroy the venom. Though most people never require even one treatment of antivenin in their lifetime, let alone several, people who work with snakes or other venomous animals may.

Aristolochia rugosa and Aristolochia trilobata, or "Dutchman's Pipe," are recorded in a list of plants used worldwide and in the West Indies, South and Central America against snakebites and scorpion stings. Aristolochic acid inhibits inflammation induced by immune complexes, and nonimmunological agents (carrageenan or croton oil). Aristolochic acid inhibits the activity of snake venom phospholipase (PLA2) by forming a 1:1 complex with the enzyme. Since phospholipase enzymes play a significant part in the cascade leading to the inflammatory and pain response, their inhibition could lead to relief of problems from scorpion envenomation.

Venom is also found in a few reptiles besides snakes, such as the gila monster, Mexican beaded lizard and certain members of the genus Varanus, such as the perentie and Komodo dragon.

Mammals

Main article: Venomous mammals

Some mammals are also venomous, including solenodons, shrews, the slow loris, and the male platypus.

Amphibians

There are only a few species of venomous amphibians; certain salamandrid salamanders can extrude sharp venom-tipped ribs.

Dinosaurs

Sinornithosaurus, a genus of feathered dromaeosaurid dinosaur, may have had a venomous bite.

See also

• Envenomation
• Schmidt Sting Pain Index
• Big Four (Indian snakes)
• List of venomous animals

Bibliography

• Smith WL, Wheeler WC (2006). "Venom evolution widespread in fishes: a phylogenetic road map for the bioprospecting of piscine venoms". J. Hered. 97 (3): 206–17. doi:10.1093/jhered/esj034. PMID 16740627.

• Lans C, Harper T, Georges K, Bridgewater E (2001). "Medicinal and ethnoveterinary remedies of hunters in Trinidad". BMC Complement Altern Med. 1: 10. doi:10.1186/1472-6882-1-10. PMC 60997. PMID 11737880.{{cite journal}}: CS1 maint: multiple names: authors list (link) CS1 maint: unflagged free DOI (link)