Numerous animal species naturally produce chemical toxins which are used to kill or incapacitate prey or as a defense against predators. Venomous animals actively deliver their toxins (called venom) into their target through a specially designed mechanism, such as a bite or sting, by using a venom apparatus, such as fangs or a stinger, in a processes called envenomation.[1][2] They are often distinguished from poisonous animals, which instead passively deliver their toxins (called poison) to their victims upon contact such as through inhalation, absorption through the skin, or after being ingested.[1][2][3] The only difference between venomous animals and poisonous animals is how they deliver the toxins.[3] This list deals exclusively with venomous animals.
Venoms have adapted to serve a wide variety of purposes. Their intended effects can range from mild fleeting discomfort to paralysis and death, and they may be highly selective in which species they target, often making them harmless to all but a few specific organisms; what may be fatal to one species may be totally insignificant to another species. Because the definition of "venomous" can be extremely broad, this list includes only those animals with venom that is known or suspected to be medically significant for humans or domestic animals.
Further information: Arachnidism and List of medically significant spider bites |
Strictly speaking, all spiders and scorpions possess venom, though only a handful are dangerous to humans. Spiders typically deliver their venom with a bite from piercing, fang-like chelicerae; scorpions sting their victims with a long, curved stinger mounted on the telson.
Of more than a thousand known species of scorpion, only a few dozen have venom that is dangerous to humans,[6] most notably the bark scorpions, including:
Further information: Insect bites and stings and List of biting or stinging arthropods |
Many species of octopus, squid, and cuttlefish make use of venom when hunting their prey.
Glyceridae, also called bloodworms, is a family of carnivorous polychaete worms which have an eversible proboscis equipped with four jaws connected to venom glands, used for killing the invertebrates they feed on.[13]
Further information: Venomous fish |
There are at least 1,200 species of venomous fish, including:
Further information: Venomous snakes, Snake venom, and Snakebite |
Some scientists have proposed that Sinornithosaurus had a venomous bite, but recent evidence suggests otherwise.[16]
Though there are numerous poisonous amphibian species capable of secreting lethal toxins through their skin, relatively few amphibians are truly venomous.
Further information: Venomous mammals |
Only a few modern mammal species are capable of producing venom; they are likely the last living examples of what was once a more common trait among the mammals. The definition of "venomous" becomes less distinct here, however, and whether some species are truly venomous is still debated.