New species of ‘pumpkin toadlet’ poisonous frog discovered in Brazil

Tiny frog which glows under ultraviolet light discovered in rainforest mountains

Pumpkin Toadlets are among some of the world’s smallest frog species (Ivan Nunes)

It’s poisonous, it glows green under ultraviolet light and it’s bright orange. Say hello to the tiny pumpkin toadlet.

This is a new species of poisonous frog found by researchers in the mountains of Brazil.

There are many species already known which fall into the pumpkin toadlet category - some of which are among the smallest frogs in the world.

A research team studying the differences between populations of pumpkin toadlets discovered the new species in the southern Mantiqueira mountains in Brazil’s Atlantic Forest.

The discovery followed two years of field surveys at the Projeto Dacnis reserve and Reserva das Araucárias, both in the state of São Paulo.

The frog, named Brachycephalus rotenbergae, is differentiated from other pumpkin toadlets by its more rounded snout, dark spots on its head and a different acoustic profile to its song which are unlike those of pumpkin toadlets already described.

The researchers said the species does not spend a large amount of time in water and its key habitat is the forest floor where it is most active during the day.

They also suggested its bright orange colours could be more important for communication than its song. Some species of pumpkin toadlets are unable to hear even their own calls.

When exposed to ultraviolet light, parts of the frog’s head and abdomen are seen glowing neon green, though the scientists said they still don’t know why.

Study author Ivan Nunes, professor in the department of Biological and Environmental Sciences at São Paulo State University, told CNN he believed the best moment as a scientist is when you are looking at something and “you are the only person who knows at that moment,” he said.

The newly identified species of toadlets is poisonous, but their threat to humans is minimal, Nunes said.

Humans can touch them with their bare hands, but they should be careful not to touch their eyes or mouth afterward, he added.

The toadlets secrete a poison called tetrodotoxin, which is the same toxin found in fugu fish.

The research team said they do not yet know how long the species’ lifespan is or how many are in the wild, but Professor Nunes said he estimates there are a couple of hundred in the area.

The team aims to conduct further research on the bright orange toadlets to learn why they are fluorescent and also to monitor them for conservation purposes.

“There’s an idea that fluorescence acts as signals for potential mates, to signal to rival males or some other biological role,” Professor Nunes said according to the Smithsonian Magazine.

Though the species does not appear to be endangered, the scientists warned that growing numbers of feral boar in the area could pose a problem to the pumpkin toadlets in the future, and further monitoring is planned.

The research is published in the journal Plos One.