Blog

Same same but different: uncovering the cryptic diversity of Asian horned frogs

By: Benjamin Tapley, Category: AMRI, Date: 21 Dec 2017

Discovering new species of horned frogs, after the fieldwork is done.

Horned frogs

Horned frogs
Photographer: Benjamin Tapley © Benjamin Tapley

Amphibians are in serious trouble, more than a third of the approximately 7770 species are threatened with extinction and we still don't even know how many amphibian species there are. It is literally a race to describe species, assess their conservation status and then develop and implement conservation projects before they are lost forever.

Southeast Asia has one of the fastest rates of deforestation on the planet and is also home to an extremely diverse amphibian fauna, with new frogs being described from the region on an almost monthly basis. I have been collaborating with the Australian Museum Herpetology Team since 2015; together we have undertaken gruelling amphibian surveys on some of Vietnam's highest mountains, trained early stage Vietnamese herpetologists in amphibian field survey techniques and described a new species of horned frog. Our work is ongoing and we are currently planning for the 2018 field season which I am sure will be wet, muddy and arduous but great for frogs!

The Asian horned frogs are a fascinating group of frogs and have been the subject of some debate in the taxonomy literature, primarily because they are so poorly known. These enigmatic frogs are restricted to forested habitats in southeast Asia, China and northeast India. They start off as bizarre looking tadpoles with extremely specialised funnel like mouthparts, they swim just below the surface of the water feeding on suspended particles in the water. Adult frogs are nearly always brown and possess a number of folds which resemble leaf veins and are so well camouflaged they almost melt into the forest floor.

Come breeding season the male leaf frogs are much more obvious and by night they can often be found emitting loud mating calls from rock, branches and vegetation beside fast flowing streams. Each species of frog has a slightly different call and so calls are extremely important to record to help identify species.

During my time at the Australian Museum I have been examining the large collection of Asian horned frogs under the guidance of Dr Jodi Rowley. We have been trying to define the small differences between individuals that have often been collected at the same site as it is our suspicion that many of these individuals represent cryptic species that are currently unknown to science. Differences between species can be quite small but after examining all the specimens patterns gradually began to emerge. Fortunately we also have corresponding genetic samples and call recordings which may lend support to the morphological differences and we are now confident that there are several new species waiting to be described from within the museum's unique collection.

These new species of horned frogs are likely to be highly threatened as they are thought to occur in relatively small areas of forest that are being destroyed or altered at an alarming rate. We are also assessing their conservation status so that the most highly threatened species can be prioritised for conservation without delay.

International collaboration is pivotal if we are to make any difference to the conservation of amphibians at the global scale. The Australian Museum Research Institute Visiting Fellowship has been a fantastic experience. With the support of the Herpetology Team I have been shown how to analyse genetic samples in the laboratory, analyse the calls of amphibians and determine the age of frogs from their skeletons, essential skills when working with this amazing, group of frogs which all look very much the same, but are in fact, quite different.

 

Benjamin Tapley
Curator of Herpetology, Zoological Society of London
AMRI Visiting Research Fellow, Herpetology