Poisonous amphibians are

amphibians Amphibians are four-limbed and ectothermic vertebrates of the class Amphibia. All living amphibians belong to the group Lissamphibia. They inhabit a wide variety of habitats, with most species living within terrestrial, fossorial, arbore ...

that produce

toxin A toxin is a naturally occurring organic poison produced by metabolic activities of living cells or organisms. Toxins occur especially as a protein or conjugated protein. The term toxin was first used by organic chemist Ludwig Brieger (1849– ...

s to defend themselves from

predators Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the ...

Amphibians

Most toxic amphibians are poisonous to touch or eat. These amphibians usually sequester toxins from animals and plants on which they feed, commonly from poisonous insects or

poisonous plants Plants that produce toxins are referred to as poisonous plants. Plants that cause irritation on contact are also described as "poisonous". The toxins in poisonous plants affect herbivores, and deter them from consuming the plants. Plants cannot ...

. Except certain salamandrid

salamanders Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All ten ...

that can extrude sharp venom-tipped ribs, and two species of frogs with venom-tipped bone spurs on their skulls, amphibians are not known to actively inject

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. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a sti ...

Toxic Frogs and Toads

An example of poison ingestion derives from the poison dart frog. They get a deadly chemical called

lipophilic Lipophilicity (from Greek λίπος "fat" and φίλος "friendly"), refers to the ability of a chemical compound to dissolve in fats, oils, lipids, and non-polar solvents such as hexane or toluene. Such non-polar solvents are themselves lipop ...

alkaloid Alkaloids are a class of basic, naturally occurring organic compounds that contain at least one nitrogen atom. This group also includes some related compounds with neutral and even weakly acidic properties. Some synthetic compounds of similar ...

from consuming a poisonous food in the

rainforest Rainforests are characterized by a closed and continuous tree canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforest can be classified as tropical rainforest or temperate rainfores ...

. They are immune to the poison and they secrete it through their skin as a defense mechanism against predators. This poison is so efficient, the native people of the

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...

Amazon rainforest The Amazon rainforest, Amazon jungle or ; es, Selva amazónica, , or usually ; french: Forêt amazonienne; nl, Amazoneregenwoud. In English, the names are sometimes capitalized further, as Amazon Rainforest, Amazon Forest, or Amazon Jungle. ...

use the frogs' toxins on their weapons to kill their prey, giving the frogs their nickname the "poison dart frog".

Toxic Salamanders

Recreational ingestion of toxins

Some people use the

bufotoxins Bufotoxins are a family of toxic steroid lactones or substituted tryptamines of which some may or may not be toxic. They occur in the parotoid glands, skin, and poison of many toads (genus ''Bufo'') and other amphibians, and in some plants and mus ...

of some species of toxic toads as a drug to get high, but this can become very dangerous. Usually due to the toads' size and toxicity, the poisons would not be deadly to a fully grown, healthy adult. But if too much of the toxin is absorbed, or if the person is young or ill, then the poisons can become a serious threat. It also depends on species: some amphibians do have toxins strong enough to kill even a healthy mature person within just a few minutes, while other species may not have toxins potent enough to have any effect. Licking toads is not biologically practical. For these tryptamines to be orally activated, the human

monoamine oxidase Monoamine oxidases (MAO) () are a family of enzymes that catalyze the oxidation of monoamines, employing oxygen to clip off their amine group. They are found bound to the outer membrane of mitochondria in most cell types of the body. The first ...

system must be inhibited. Therefore, licking a poisonous amphibian will not guarantee a sufficient dose.

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