A new frog species with flashy red thighs has just been revealed from the rugged forests of northern Vietnam and southern China

A new species of Horned Frog has just been discovered from the Hoang Lien Mountains in northern Vietnam and southern China. With flashy red thighs and tiny horns over its eyes, it wasn’t until we listened to its call and examined its DNA that we could confirm that the little frog was indeed new to science, and not another similar-looking species. The Red-thighed Horned Frog (Megophrys rubrimera) is known only from the Hoang Lien Mountain Range in northern Vietnam and southern China.

Over the past couple of decades, amphibian declines have made the headlines; nearly half of amphibian species are threatened with extinction, making them the most threatened vertebrate group on the planet. They are also amongst the most poorly-known, and our estimate of amphibian species diversity is seriously underestimated.

One country that has a rich but poorly-known amphibian fauna is Vietnam. More than 70 new species of amphibian have been described from Vietnam in the past 12 years alone and many more await description.

In 2015, we began a collaborative project aimed at conserving two newly described and highly threatened amphibian species that were only known from the Hoang Lien Range, a rugged mountain range in the far north of Vietnam, which extends into southern China. This mountain range has long attracted amphibian biologists to its misty slopes and approximately 80 amphibian species have been recorded in the area.

During fieldwork in the mountains, we encountered a tiny brown frog that didn't quite look like any described species. Just 3cm in length, with vivid red thighs, the strange-looking frog resembled a species that had been described from eastern China in the 1920s, but something about its shape and colouration was not quite right. After examining the frogs, their calls and their DNA, it was clear that we were in fact dealing with a species new to science. The vivid orange red colour of the thigh was one of the most obvious characters that differentiated this species from its relatives – hence the name of the species.

Why is this new finding significant? This species epitomises the problems faced by amphibians globally. The species, being new, is of course like the majority of amphibian species in being poorly known. Being small and predominantly brown does not attract the same attention as being large and brightly coloured! Indeed, this tiny frog had been encountered by biologists working in the region over 15 years ago but was overlooked. In addition, as the only forest patches it is known from in Vietnam are extremely degraded and encroached upon by agriculture, the new species is likely to be Endangered and in need of conservation attention.

Without a name it is extremely difficult to place a species on the conservation agenda, it is hoped that now we at least know some basic information about this species (where it lives, what it looks like, what it sounds like and a little about the larval stage), it can be incorporated into the conservation decision making process and continue to live in the mountains of the Hoang Lien Range for many years to come.

Benjamin Tapley, Curator of Herpetology, Zoological Society of London & AMRI Visiting Research Fellow
Dr Jodi Rowley, Curator of Amphibian & Reptile Conservation, AMRI & UNSW
Tim Cutajar, Herpetology Research Assistant, AMRI

This research is a partnership between the Australian Museum, Zoological Society of London (ZSL) and Hoang Lien National Park's Centre for Conservation and Rescue of Organisms.

More information:
• Tapley, B., Cutajar, T., Mahony, S., Nguyen, C.T., Dau, V. Q., Luong, H.V. & Rowley, J.J.L. (2017). The Vietnamese population of Megophrys kuatunensis (Amphibia: Megophryidae) represents a new species of Asian horned frog from Vietnam and southern China. Zootaxa 4344 (3): 465–492
• Tapley, B., Rowley, J.J.L., Nguyen, T.C. & Luong. V.H. (2017) An action plan for amphibians of the Hoang Lien Range 2017-21.