Brazil: Toxic Frogs’ Venom Can Be Lethal

Unbelievably, frogs can be some of the most lethal creatures on Earth. If we take a relevant example – the 2-inch-long golden poison dart frog is able to kill 10 grown men with its toxin.

Regarding their natural habitat, venomous frogs live in forest environments, however predators avoid them as a result of their toxicity.

Greening’s casque-headed tree frog, (scientifically, Corythomantis greeningi) possesses a lesser dose of poisonous venom, though it exhibits characteristics (bigger head spines, pores and skin glands) that enable it to secrete extra venom, that makes it more dangerous and lethal than the Bruno’s casque-headed frog (Aparasphenodon brunoi).

Greening’s and Bruno’s casque-headed frogs live in Brazil. The natural habitats of the Greening’s frogs are dry or moist savannas, rivers and rocky areas, whereas the Bruno’s frog prefers subtropical or tropical forests, tropical shrubland (vegetation dominated by shrubs), and intermittent fresh water marshes. However, the latter is threatened by habitat loss.

It seems the venomous spikes of the frogs were discovered accidentally. Researchers assume that frogs use their venomous spikes to defend against predators, vs. serving to them hunt prey.

Another remarkable aspect is that 1 gram Bruno’s frog’s venom would be sufficient to take the lives of 80 people, or 300.000 mice.

Edmund Brodie Jr. of Utah State University, has been exploring amphibians’ defense mechanisms his whole career, working with South American institutions too. The biologist reported that the frogs display bony spines (a sort of backbones or pointed projections) on their noses, backs of their heads and jaws. These spines are used to put the venom inside the wound directly, this being their active defense mechanism.

These frogs exhibit abnormally versatile necks for their species, and when grabbed, they hurl venom from their pores and glands round their spines, rubbing their spines against anything or anyone that might make them feel threatened.

One single gram from C. greeningi could affect 24.000 pests and 4 human populations. Brodie hopes we won’t experience the disastrous effect of the venom of the most toxic amphibians. He suspects that these tiny creatures are immune to their own venom, nevertheless, whereas their venom is worse than that of a pit viper.

What does make sense is that the two mentioned species do not have natural predators in the wild, scientists report.

An unfortunate event was when Carlos Jared, of a biological institute in Brazil, was collecting specimens of the frog C. greeningi, when his hand was injured by one of its head-located spines. He felt excruciating pain in his arm that lasted for 5 hours.

So, as Brodi points out, scientists are facing a whole new level of anti-predator defense strategies than they have ever imagined.

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