New toothed toad found by conservationists for first time in Vietnam’s ‘froggy hotspot’

ZSL (Zoological Society of London) herpetologists have described a new amphibian species for the first time – after making the surprise discovery while searching for a different animal. 

The newly-described Mount Po Ma Lung toothed toad (Oreolalax adelphos) has been named by an international team of conservationists after the mountain on which it was found – in Vietnam's Hoàng Liên mountain range, a known global hotspot for threatened species. 

ZSL EDGE Fellow Luan Thanh Nguyen led a group expedition to find a known toad in the region, and instead they found a species unknown to science. 

Following a gruelling 12-hour-long hike during an eight-day-long survey of the mountain range, the conservationists climbed to the peak of Mount Po Ma Lung in search of the Sterling's toothed toad. On the way down from the 2967-metre-high summit, the research group found the Mount Po Ma Lung toothed toad on a path well-trodden by tourists, and upon spotting its unfamiliar colour markings, quickly believed it to be a new and undescribed species. 

True to its name, the Mount Po Ma Lung toothed toad has a row of tiny teeth on the roof of its mouth, known as vomerine teeth. The newly described amphibian is covered with black, cream and grey spots and has several unique features, including a narrow fold of skin behind its eyes, a distinct mottled pattern on its belly, and an eye-catching two-toned iris. 

The forest habitat of the Mount Po Ma Lung toothed toad is under threat from habitat destruction, driven by fuelwood collection for the tourism industry, as well as the creation of cardamom plantations on the lower slopes of the mountain. While conservationists are still gathering information on whether this species is highly threatened, it could rank as Critically Endangered on the IUCN Red List if further research confirms its reliance on this singular, small high-altitude home around the summit of Mount Po Ma Lung.  

The forest habitat of the Mount Po Ma Lung toothed toad is under threat from habitat destruction, driven by fuelwood collection for the tourism industry, as well as the creation of cardamom plantations on the lower slopes of the mountain. While conservationists are still gathering information on whether this species is highly threatened, it could rank as Critically Endangered on the IUCN Red List if further research confirms its reliance on this singular, small high-altitude home around the summit of Mount Po Ma Lung.  

Dr Ben Tapley, London Zoo’s Curator of Reptiles and Amphibians and the paper’s co-author, said: “This is a very exciting new discovery, and one that highlights the need to protect the forests of the Hoàng Liên Range and their remarkable biodiversity. Over the past 10 years, we have described 6 frogs and a snake as new species to science; now we have the important task of working with our partners to conserve them.”  

The species is the second Oreolalax amphibian to be found in Vietnam – the first being the Sterling’s toothed toad – with both found on Mount Po Ma Lung. Its species name “adelphos”, meaning brother in Greek, acknowledges this link between the toothed toad species. This new species was described in a study published in Zootaxa by an international team led by ZSL’s EDGE (Evolutionary Distinct and Globally Endangered) Fellow Luan Thanh Nguyen, and London Zoo’s amphibian team, experts from the Asian Turtle Program of Indo-Myanmar Conservation, the Chengdu Institute of Biology, The Australian Museum and Australia's Centre for Ecosystem Science.  

ZSL EDGE Fellow and lead researcher on the paper Luan Thanh Nguyen of Indo-Myanmar Conservation, who is based in Vietnam, said: “The discovery of Oreolalax adelphos is a surprising finding and the result of a truly unforgettable day of searching, climbing to the mountain’s highest summit. Our initial goal on this trip was to find a Sterling's toothed toad, but while surveying Mount Po Ma Lung under very challenging weather conditions, we came across what we're thrilled to have uncovered a species that is new to science: the Mount Po Ma Lung toothed toad. 

“This important discovery in our Hoàng Liên Range amphibian research brings us one step closer to better knowledge of the true diversity of amphibians in Vietnam’s high mountain ranges.” 

Vietnam has the highest rate of amphibian species discovery in mainland southeast Asia, but there are relatively few conservation initiatives focussing on amphibians in the country.  

Previous discoveries led by ZSL EDGE teams include the Mount Fansipan horned frog in 2018 and the Mount Pu Ta Leng leaf-litter frog in 2021. The team hope that their continued work will help raise awareness to the importance of the region for amphibians and encourage further conservation work in the region.   

The Hoàng Liên Range supports an array of over 80 spectacular amphibian species, many of which are highly threatened and found nowhere else on the planet.    

Tapley added: “Recent infrastructural developments for the tourist industry in the Hoàng Liên Range have led to habitat degradation. If we are to protect some of our rarest amphibian species, striking a balance between biodiversity conservation and the area’s economic growth is essential. By focusing on sustainable ecotourism initiatives, we can work to protect the region's remarkable amphibian diversity before it's too late.”