Poison dart frogs are well known for their brightly colored skin. The bright colors warn potential predators of their toxicity.

Poisonous amphibians are amphibians that produce toxins to defend themselves from predators.

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. Except certain salamandrid salamanders that can extrude sharp venom-tipped ribs,[1][2] and two species of frogs with venom-tipped bone spurs on their skulls, amphibians are not known to actively inject venom.

Toxic Frogs and Toads

An example of poison ingestion derives from the poison dart frog. They get a deadly chemical called lipophilic alkaloid from consuming a poisonous food in the rainforest. 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 American Amazon rainforest use the frogs' toxins on their weapons to kill their prey, giving the frogs their nickname the "poison dart frog".

Image Scientific name Active agent Distribution
Dendrobatidae Poison Dart Frogs lipophilic alkaloid toxins: allopumiliotoxin 267A, batrachotoxin, epibatidine, histrionicotoxin, pumiliotoxin 251D humid, tropical environments of Central and South America
Mantella genus Golden frogs or Malagasy poison frogs alkaloid toxins Madagascar
northern corroboree frog (Pseudophryne pengilleyi) pseudo-phrynamine Southern Tablelands of Australia.
southern corroboree frog (Pseudophryne corroboree) pseudo-phrynamine Southern Tablelands of Australia.
Bruno's casque-headed frog (Aparasphenodon brunoi) Unknown injectable venom[3] Brazil
Greening's frog (Corythomantis greeningi) Unknown injectable venom[3] Brazil
Panamanian golden frog (Atelopus zeteki) Zetekitoxin AB, Bufadienolide Central Panama.
American toad (Anaxyrus americanus) Bufotoxin eastern United States and Canada.
Colorado River toad (Incilius alvarius) 5-MeO-DMT, Bufotenin southeastern California, New Mexico, Mexico and much of southern Arizona
Rhinella arenarum Bufotoxin Argentina from the Chubut Province northward, Bolivia east of the Andes, southern Brazil, and Uruguay
Asian giant toad (Phrynoidis asper) Bufotoxin Mainland Southeast Asia and the Greater Sundas.
Colombian giant toad, Blomberg's toad (Rhaebo blombergi) Bufotoxin western Colombia (Chocó, Valle del Cauca, Cauca, and Nariño Departments) and northwestern Ecuador (Carchi, Esmeraldas, and Imbabura Provinces)
western toad (Anaxyrus boreas) Bufotoxin western British Columbia and southern Alaska south through Washington, Oregon, and Idaho to northern Baja California, Mexico; east to Montana, western and central Wyoming, Nevada, the mountains and higher plateaus of Utah, and western Colorado.
common toad, European toad Bufo bufo bufotalin, bufalitoxin and bufotoxin Europe
Asiatic toad or Chusan Island toad (Bufo gargarizans) Bufotoxin East Asia.
African common toad or guttural toad (Sclerophrys gutturalis) Bufotoxin Angola, Botswana, Democratic Republic of the Congo, Kenya, Lesotho, Malawi, Mauritius, Mozambique, Namibia, Réunion, Somalia, South Africa, Ethiopia, Eswatini, Tanzania, Zambia, and Zimbabwe.
Japanese common toad, Japanese warty toad or Japanese toad (Bufo japonicus) bufotalin, Bufotoxin Japan and is present on the islands of Honshu, Hokkaido, Kyushu and Shikoku
Fowler's toad (Anaxyrus fowleri) Bufotoxin eastern United States and parts of adjacent Canada
cane toad (Rhinella marina) Bufotoxin, Bufotenin Rio Grande Valley in South Texas to the central Amazon and southeastern Peru, and some of the continental islands near Venezuela (such as Trinidad and Tobago) Introduced in Australia, Florida and Hawaii, Papua New Guinea, the Philippines, the Ogasawara, Ishigaki Island and the Daitō Islands of Japan, most Caribbean islands, Fiji and many other Pacific islands
Asian common toad (Duttaphrynus melanostictus) Bufotoxin South and Southeast Asia.
Peltophryne peltocephala Bufotoxin Cuba
oak toad (Anaxyrus quercicus) Bufotoxin southeastern United States.
African common toad, square-marked toad, African toad (Sclerophrys regularis) Bufotoxin Angola, Benin, Burkina Faso, Cameroon, Cape Verde, Central African Republic, Chad, Republic of the Congo, Democratic Republic of the Congo, Ivory Coast, Egypt, Ethiopia, Gabon, Ghana, Guinea, Guinea-Bissau, Kenya, Liberia, Mali, Niger, Nigeria, Rwanda, Senegal, Sierra Leone, Sudan, and Uganda.
Gulf Coast toad (Incilius valliceps) Bufotoxin eastern and southeastern Mexico and Central America as far south as Costa Rica.
European green toad (Bufotes viridis) Bufotoxin mainland Europe, ranging from far eastern France and Denmark to the Balkans and Western Russia.

Toxic Salamanders

Image Scientific name Active agent Distribution
Taricha genus Western Newt Tetrodotoxin Pacific coastal region from southern Alaska to southern California, and Mexico
Triturus genus crested and the marbled newts Tetrodotoxin Great Britain through most of continental Europe to westernmost Siberia, Anatolia, and the Caspian Sea region
Notophthalmus genus Tetrodotoxin[4] eastern United States, Mexico
Salamandra genus samandarin, samandarone, O-acetylsamandarine[5] southern and central Europe
Iberian ribbed newt (Pleurodeles waltl) Unknown [6] central and southern Iberian Peninsula and Morocco.

Recreational ingestion of toxins

Some people use the bufotoxins 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 system must be inhibited. Therefore, licking a poisonous amphibian will not guarantee a sufficient dose.

See also

References

  1. ↑ "Venomous Amphibians (Page 1) - Reptiles (Including Dinosaurs) and Amphibians - Ask a Biologist Q&A". Askabiologist.org.uk. Retrieved 2010-07-28.
  2. ↑ Robert T. Nowak & Edmund D. Brodie Jr. (1978). "Rib Penetration and Associated Antipredator Adaptations in the Salamander Pleurodeles waltl (Salamandridae)". Copeia. 1978 (3): 424–429. doi:10.2307/1443606. JSTOR 1443606.
  3. 1 2 Jared, Carlos; Mailho-Fontana, Pedro Luiz; Antoniazzi, Marta Maria; Mendes, Vanessa Aparecida; Barbaro, Katia Cristina; Rodrigues, Miguel Trefaut; Brodie, Edmund D. (2015). "Venomous Frogs Use Heads as Weapons" (PDF). Current Biology. Elsevier BV. 25 (16): 2166–2170. doi:10.1016/j.cub.2015.06.061. ISSN 0960-9822. PMID 26255851.
  4. ↑ Spicer, Mackenzie M.; Stokes, Amber N.; Chapman, Trevor L.; Brodie, Edmund D.; Brodie, Edmund D.; Gall, Brian G. (2018-09-02). "An Investigation into Tetrodotoxin (TTX) Levels Associated with the Red Dorsal Spots in Eastern Newt (Notophthalmus viridescens) Efts and Adults". Journal of Toxicology. 2018: 1–4. doi:10.1155/2018/9196865. ISSN 1687-8191. PMC 6139183. PMID 30245715.
  5. ↑ Lüddecke, Tim; Schulz, Stefan; Steinfartz, Sebastian; Vences, Miguel (2018-09-04). "A salamander's toxic arsenal: review of skin poison diversity and function in true salamanders, genus Salamandra". The Science of Nature. Springer Science and Business Media LLC. 105 (9–10): 56. Bibcode:2018SciNa.105...56L. doi:10.1007/s00114-018-1579-4. ISSN 0028-1042. PMID 30291447. S2CID 52924816.
  6. ↑ Rosania, Kara (July 2014). "Newts with superpowers - Lab Animal". Lab Animal. 43 (7): 231. doi:10.1038/laban.575. PMID 24945218. S2CID 1977413. Retrieved 2021-01-05.
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