Two Brazilian Frog Species Pack Lethal Dose of Toxin Atop Skull Spikes

It’s not much of a surprise that in the world of amphibians some are poisonous or venomous or both.

But the discovery of two species of frogs that both poisonous and venomous at the same time, and quite aggressive, took researchers by surprise.

The species, titled Corythomantis greeningi or more commonly known as Greening’s frog and its cousin Aparasphenodon brunoi have a surprising anatomical structure depicting spiked skulls that the frogs will use as a defensive mechanism.

Both species have been described centuries ago, but knowledge of their existence was lost in time. Carlos Jared of the Instituto Butantan, Sao Paulo had the ‘pleasure’ of finding out on his own skin how aggressive the tiny fellows are and how unusual their defensive mechanism is.

Aided by colleague Edmund Brodie Jr. of the Utah State University, Jared set out to collect specimens of frogs in Brazil.

Their findings are detailed in the Current Biology journal, in a research paper published on August 6th.

To get an understanding of how dangerous these Brazilian frogs are, read Brodie’s declaration:

“Discovering a truly venomous frog is nothing any of us expected, and finding frogs with skin secretions more venomous than those of the deadly pit vipers of the genus Bothrops was astounding”.

Greening’s frog is easily recognizable by its green skin and the sturdy plate that is its head. Flattened as it is, the frog’s head packs an impressive collection of spikes that would prevent predators from ever catching them. These spikes are so efficient that the frog has no known enemies in the animal kingdom.

As the bones of the skull fused together to create this flattened plate bordered by the lower layer of skin, the adaptation is an efficient mechanism that protects the Greening’s frog from dehydration.

As the Caatinga forests are dry, the frogs need their humidity and water. So the flattened head is also used as a shovel and a plug for the deep humid holes that are the frogs’ abodes. Sheltered here, any predator that would attempt to feed on the amphibians is in for a surprise.

The wicked spiked adorning the frogs’ heads do not work alone. The frogs’ skulls, as their skin is packed with glands that release a toxic mucus that is lethal. Most prominents on the skull, the glands ensure the frogs that they have a double-edged advantage.

They produce the toxin that is then injected in a predator’s body as the frog’s spiked skull pierces through the skin.

As mentioned on the onset, these Brazilian frogs are both venomous and poisonous, as they pack active and passive defence in one tiny body. Not so fragile, as it stands.

Photo Credits: nationalgeographic.com