A team of researchers detailed Corythomantis greening, the first venomous frog on record, and differentiated them from poisonous frogs.
According to Live Science, the venomous frogs discovered in Brazil were observed using their poison offensively, rather than strictly as a defense mechanism, as a poisonous frog would. The new study is published in the journal Current Biology.
"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," study co-author Edmund Brodie, Jr. of Utah State University, said in a press release. "It is unlikely that a frog of this species produces this much toxin, and only very small amounts would be transferred by the spines into a wound.
"Regardless, we have been unwilling to test this by allowing a frog to jab us with its spines."
Carlos Jared, a researcher at the Butantan Institute in São Paulo and the lead author on the study, learned of the frog's venomous offense firsthand. Brodie told Live Science Jared endured "intense pain... lasting for five hours" after a frog caught him on the hand with a venomous spike.
Most amphibians can release poison when in danger, but this is the first example of one using it as a weapon, and a particularly harsh one at that.
"The strength of toxicity of the skin secretions is remarkable, and to say we were surprised by that is an understatement," Brodie told Live Science. "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. It moves the study of amphibian defenses to a new level."
