If you're like most people, you might walk up on a pretty frog or some toads and pick it up. Ok, most people probably wouldn't do that, which is a good thing seeing as some species of frog are some of the most toxic animals on the planet. What makes a toad or frog poisonous isn't the same as what makes a snake venomous. It has a lot to do with what they eat, but thanks to their particular biology, they have the ability to secrete poisons that can kill an adult human on contact!
The most poisonous frogs in the world that are considered deadly to humans are usually found in places you probably wouldn't run into them, but that doesn't mean you should go around hunting frogs. Many of these frogs are beautiful in coloring and look perfectly benign, but don't let their small stature and cute looks fool you, picking up a poisonous frog could very well be the last thing you ever do so take note of these little hoppers and respect the deadliest frogs on the planet.
Mantella, commonly known as either Golden Frogs or Malagasy Poison Frogs, is a species of poisonous frogs found only on the island of Madagascar. They are an example of convergent evolution in that they are incredibly similar to Latin America's Poison Dart Frogs in toxicity, size, shape, and coloring, but are not related to them in any way.
Like their evolutionarily similar cousins, they secrete a deadly toxin through their skin, which is derived from a diet of mites, flies, ants, and collembolans. In another strange similarity, they are preyed upon by a single species of snake and skink, both of which have evolved an immunity to their otherwise deadly toxin. They are commonly kept as pets via the exotic animal trade and are not dangerous to own and handle so long as they aren't fed the diet that builds up their toxicity in the wild.
- Scientific Name: Mantella
Cane Toads hold the distinction of being the largest species of toad on the planet. They are an old species capable of growing up to as much as 9.4 inches (24 cm) in length, though that is their largest recorded size. Because of their predatory nature, they have been introduced into agricultural areas all over the world so they could subsist on pests, but they eventually became pests themselves due to a lack of competition.
Cane Toads develop their toxicity early in development and their tadpoles are deadly to most animals if eaten. They produce a poison from glands, which secretes through their skin and makes them incredibly dangerous to small animals like dogs who might try to take a bite out of them.
- Scientific Name: Rhinella marina
The Common Toad, otherwise known as the European Toad, is a species of toad found throughout Europe save for Ireland and Iceland. Their range also extends East into the Western parts of Northern Asia and down into Northwest Africa making their range relatively extensive. Like many other toads, the Common Toad produces a bufotoxin they secrete through their skin.
Unlike most toads, the bufotoxin of a Common Toad can lead to severe complications in people and even death, which is a problem due to a lack of any known antivenom. Interestingly, their toxin has numerous uses in modern medicine. It can be used to treat congestive heart failure bt increasing the strength and rate the heart muscle contracts. That's in a laboratory environment though and due to the high toxicity of these animals, they shouldn't be handled without proper care and precaution.
- Scientific Name: Bufo bufo
The Asiatic Toad, commonly called the Chusan Island Toad, is often found throughout China and other regions of Asia to include the Russian Far East and into the Korean Peninsula. They are very common and play an important role in traditional Oriental medicine thanks to the toxin they secrete, which is often referred to as Toad Venom.
The toxin Asiatic Toads secrete is a type of bufotoxin, which is used for various medicinal properties. It has even found a path into Western Medicine as an antimicrobial peptide that can be extracted from the venom. When used improperly... say, for the development of aphrodisiacs, the bufotoxin from an Asiatic Toad can lead to heart attacks and death in humans.
- Scientific Name: Bufo gargarizans