Herpetologist Ivan Sergio Nunes Silva of São Paulo State University along with other colleagues have described a new species of toadlet from Brazil’s Atlantic Forest – which has already lost over 90% of its original forest cover. 

The new species is of the Brachycephalus genus, known as the saddleback toads. These toads are split into two further kinds, the pumpkin toads – as B. nodoterga above is – and flea toads, which are a much different but well-camouflaged brown. Researchers did comment that it is also easy to mistake a bright pumpkin toad for a similarly coloured plant or fungus on the forest floor where they reside.

The new species has been named Brachycephalus rotenbergae. It shares the characteristics of the other pumpkin toadlets in its genus with its bright aposematic colouration and tiny size (1.3-1.8cm long).

The species was found as part of a specific, targeted research effort to document and conserve Brazil’s threatened biodiversity. Brazil’s forests have the most amphibian diversity in the world, but they are also some of the most vulnerable.

B. rotenbergae was distinguished from the other members of its genus via DNA analyses and morphological, behavioural and acoustic traits. It stands out by being generally smaller than its relatives, with a shorter snout, and a habitat preference of higher elevations.

These differences within genera can cause some debate among experts in the field, with some believing that B. rotenbergae is actually B. ephippium, as the genetic differences, while detectable, are extremely small (approximately 3%). At present, there have not been enough measurements of either species to make confident conclusions about whether they really are the same.

The frogs in Brachycephalidae are some of the smallest in the world.

Another trait is taking the spotlight when it comes to this toadlet – the fact that it appears to ‘glow’ under UV light. Currently, only two other pumpkin toadlet species are known to also exhibit this fluorescence.

In recent years, many animals – mammals included – have been observed to be fluorescent as well. Many of these species cannot even detect UV fluorescence, so the purpose is yet to be discovered.

Moving forward, there are likely to be more comparisons made between B. rotenbergae and its close relatives to solidify its place as a separate species. Following this, documenting the complete biodiversity profile of the remaining habitats in Brazil is a top research priority there. What remains of the Atlantic Forest is primarily nature reserve, but is still threatened by deforestation, climate change and agriculture.

In the spirit of Amphibian Awareness Week, we would like to highlight that amphibians are some of the most threatened animals across the globe, in the grip of their own kind of pandemic known as chytrid fungus. You can read about the plight of amphibians in the face of the chytrid crisis in the March issue of Exotics Keeper Magazine.

We can help by raising awareness and funding for amphibian conservation and recovery projects – even on our home turf in the UK, amphibians may be at real risk from emerging diseases and the possible introduction of chytrid.

Always make sure to follow biosecurity measures when you travel and enjoy the outdoors by disinfecting your footwear between nature sites, washing your hands when handling amphibians, reporting sick or dead individuals to your local wildlife group, and quarantining any new amphibian species you keep at home.