Conservation news

Earless African pygmy toad discovered on remote mountain in Angola

In 2016, a group of researchers set out to explore Serra da Neve Inselberg, an isolated mountain and Angola’s second-highest peak, in search of frogs and toads. Now, they have described a new and unusual species of African pygmy toad that they chanced upon during their expedition.

The new species, formally named Poyntonophrynus pachnodes, or the Serra da Neve pygmy toad, has a distinct trait that sets it apart from its close relatives: it lacks both external and internal parts of the ear that help frogs hear, researchers report in a new study published in ZooKeys.

The study’s lead author, Luis Miguel Pires Ceríaco, a herpetologist at Villanova University in Pennsylvania, U.S., said his team spotted the Serra da Neve pygmy toad on their very first night on the remote mountain. The toads were roaming around their camp, and could be seen amid leaf litter and under rocks.

“But we only noticed that the toad was different in the laboratory, under the microscope,” Ceríaco told Mongabay in an email. “Toads, especially small species like this, have a very common toad-like appearance. In the field we are usually very busy collecting, fixing and taking notes, so many times smaller details are overlooked. Even in cases like these, where an entire structure was missing!”

While earless toads aren’t rare, this is the first time a Poyntonophrynus species has been reported without ears.

“This loss of ear happened several times in frogs, especially in toads of the family Bufonidae, to which the Poyntonophrynus belongs,” Ceríaco said. “Some lineages loose it and then regain it. This is a quite interesting fact, but we still don’t know why it happens. It is a topic of many debates and investigation in the recent years. What we know is that all known members of this genus have [ears] and this one doesn’t.”

This is Serra da Neve Inselberg in southwestern Angola, the second-highest peak in Angola. Image by Luis Miguel Pires Ceríaco.

Unlike most other frogs and toads that prefer moist forests, most African pygmy toads live in dry, arid regions of Angola and Namibia in southwestern Africa. The Serra da Neve pygmy toad, currently known only from the arid mountain of the same name, fits the bill.

“Arid areas are not known to harbor that many amphibians,” Ceríaco said. “Poyntonophrynus species almost behave more like lizards than amphibians. The description of this new species just confirms this odd pattern.”

The newly described species could possibly occur around the Serra da Neve area, Ceríaco said. But further surveys would be needed to confirm that. “So little is known about Angolan herpetofauna that we barely scratched the surface of its diversity and distribution,” he said.

“The description of a new species is always a reminder of how much we still need to work here,” Ceríaco added. “Many other species, mostly endemic, are currently in the process of being formally described, and it is expected that the number of species for the country will sharply rise in the next few years. With all this, we are experiencing a rebirth on Angolan herpetology, which was delayed by the almost 40 years of civil war.”

This study was part of a bigger project looking into the diversity and distribution of Angolan herpetofauna, involving several international organizations and the Angolan Ministry of Environment.

The new earless species of African pygmy toad from Serra da Neve Inselberg, Poyntonophrynus pachnodes. Image by Ishan Agarwal.

Citation:

Luis M. P. Ceríaco, Mariana P. Marques, Suzana Bandeira, Ishan Agarwal, Edward L. Stanley, Aaron M. Bauer, Mathew P. Heinicke, David C. Blackburn. A new earless species of Poyntonophrynus (Anura, Bufonidae) from the Serra da Neve Inselberg, Namibe Province, Angola. ZooKeys, 2018; 780: 109 DOI: 10.3897/zookeys.780.25859