Venom

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.

[1][2][3] The toxin is delivered through a specially evolved venom apparatus, such as fangs or a stinger, in a process called envenomation.

[2] Venom is often distinguished from poison, which is a toxin that is passively delivered by being ingested, inhaled, or absorbed through the skin,[4] and toxungen, which is actively transferred to the external surface of another animal via a physical delivery mechanism.

[5] Venom has evolved in terrestrial and marine environments and in a wide variety of animals: both predators and prey, and both vertebrates and invertebrates.

In Polistes fuscatus, the female continuously releases a venom that contains a sex pheromone that induces copulatory behavior in males.

[29][30] Two frog species in Brazil have tiny spines around the crown of their skulls which, on impact, deliver venom into their targets.

[38][39] Some lizards possess a venom gland; they form a hypothetical clade, Toxicofera, containing the suborders Serpentes and Iguania and the families Varanidae, Anguidae, and Helodermatidae.

[41] A few species of living mammals are venomous, including solenodons, shrews, the European mole, vampire bats, male platypuses, and slow lorises.

[43] The presence of tarsal spurs akin to those of the platypus in many non-therian Mammaliaformes groups suggests that venom was an ancestral characteristic among mammals.

[37] Solenopsins extracted from fire ant venom has demonstrated biomedical applications, ranging from cancer treatment to psoriasis.

The coevolution between predators and prey is the driving force of venom resistance, which has evolved multiple times throughout the animal kingdom.

[57] The payoff for the cost of physiological resistance is an increased chance of survival for prey, but it allows predators to expand into underutilised trophic niches.

[63] Among marine animals, eels are resistant to sea snake venoms, which contain complex mixtures of neurotoxins, myotoxins, and nephrotoxins, varying according to species.

They are used to acquire prey and to deter predators by causing pain, loss of muscular coordination, and tissue damage.

Clownfish have a protective mucus that acts as a chemical camouflage or macromolecular mimicry preventing "not self" recognition by the sea anemone and nematocyst discharge.