Brazilian frogs use their venomous heads as weapons

Both of the frog species have little spines coming out of their head that the researchers discovered deliver the venom. “Amphibians have a wide array of skin toxins that have been well-studied, but this sort of mechanism – transmitting the toxin as a venom – has not been found before”.

Just a single gram of venom from one of the species – Bruno’s casque-headed frog, aka Aparasphenodon brunoi – would be enough kill 80 people, or 300,000 mice.

Their means of injection are bony spines on their heads, which were discovered when Carlos Jared of Instituto Butantan in São Paulo got stuck with one.

LiveScience reports the discovery (published August 6 in the journal Current Biology) came with a painful price.

True, several species of frogs that produce potent and quite often deadly toxins have been documented over the years. Venom is injected. Pufferfish are poisonous, vipers are venomous.

Now scientists have discovered – the hard way – two species of Brazilian frog that are venomous. Edmund Brodie said findings of the study will help understand the biology of amphibians and their relationship with natural predators.

Frogs are one of nature’s greatest tricks. On top of the frog’s skull are many bones that have fused together merging with the skin’s lower layers to create one sturdy plate. The two species, Corthythomantisgreeningi and Aparasphenodonbrunoi, have flat heads with comparatively long necks and projecting lip-like snouts.

This accident might sound fortunate in hindsight, because the species that injured Jared proved to be the much less poisonous of the 2 the researchers investigated.

The spines can release venom that is toxic, white mucus from glands in the skin, which when swallowed can be lethal.

“The level of toxicity is extreme, but the real story here is that (the frogs are) able to transmit the venom using the spikes on their head”, Brodie explained. Both have been known for decades, if not centuries. In fact, they aren’t poisonous at all; they’re venomous. There are frogs that inject venom into things.

Jared was the unfortunate recipient of a jab on the hand from C. greeningi and spent a day in agony, with excruciating pain radiating up his arm. The scientists also added that they will be conducting further research into the possibly of other venomous frogs. The reason became very obvious when he decided to collect a specimen of C. greeningi.The two frogs in question are called Corythomantis greening and Aparasphenodon brunoi. These amphibians haven’t any recognized predators, which makes good sense given these newest findings.