Researchers have discovered that frogs do not use their poison only to protect themselves form enemies, but that there are also venomous species that in addition can be more dangerous than pit vipers. Scientists have discovered the first species of venomous frogs in Brazil. The paper was published in the journal Current Biology.
The discovery was made by accident by a researcher from the Butantan Institute in São Paulo, Carlos Jared, who injured his hand on some bony spikes that were on the head of a frog species called Corythomantis greeningi. The species is found in the savannas of eastern Brazil. Unlike poisonous frogs that have no fangs to deliver toxins, venomous frogs actively release toxins.
Edmund Brodie Jr. from Utah State University in Logan said that animals that are venomous are in most cases discovered through accidents. Brodie himself related of how early in his career he discovered details of the venom released by the fire salamander while he was tickling the animals with a piece of grass in order to show to his students how the toxin is discharged. The salamander sprayed the toxin right in this eyes and Brodie explained that he was immediately blinded and the pain he felt was extraordinary. He ran water in his eyes but even after 20 minutes it did not help much because the poison was not soluble in water.
In the case of Corythomantis greeningi Jared felt intense pain in his arm which lasted for five hours. Only when he analyzed the frog’s upper lips with the microscope did he understand that head-butting discharges venom. Jared explained that the bone spikes that erupted near the venom glands were huge. When the frog curls its lip back the glands dribble toxins onto the spikes that stick out of the skull.
Researchers also observed that one gram from Corythomantis greeningicould’s venom could kill six humans and 24.000 mice. Compared with it, the venom of the Brazilian Bothrops pit viper is half as deadly.
The team has discovered a second species of venomous frog as well; Aparasphenodon brunoi. This species is 25 times more dangerous than the venom of the pit vipers. It can kill 80 humans and 300.000 mice.
The scientists are now concentrated on investigating other species of frogs from around the world which they suspect they could also be venomous frogs.
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