Author: Amaël Borzée

New lab paper on the trade of Brown Frogs (Rana sp.) in northeast Asia, including the delineation of cryptic species, and morphological tools for species identification to act against the trade of mis-identified individuals.

The trade of amphibians increases the risk of invasions across the world, and northeast Asia. To understand the trade in the area, we developed an accurate species assignment and workflow guiding a broad-scale species identification and resolving the trade pathways. We tested our workflow on unidentified cryptic brown frogs imported into the Republic of Korea.

The workflow combined morphometry, phylogenetic trait, species delimitation modelling and phylogeography, and successfully identified three non-native species imported in Korea: Rana chensinensis, Rana amurensis and Rana kukunoris out of 171 specimens bought from the trade.

Using a machine-learning approach with Bayes Factor Delimitation method to evaluate the taxonomy models from four commonly used species delimitation tools (BLAST, ABGD, sGMYC and bPTP), and isolated 12 operational taxonomic units (OTUs) from the 171 individuals. We then combined the information from the 12 OTUs and combined it into a 16S phylogeny including traded and control specimens (n = 230).

The model-based OTUs and phylogeny revealed the widespread and likely wild-harvested origins of traded Rana individuals, cycled through farm in China to be integrated in the legal trade. Apart from the genetic, our morphometry also indicates extremely high phenotype crypticity between the endemic Korean species, especially R. huanrenensis and those brown frogs from the trade.

 However, the trait evolution results also highlight a pattern of independent evolution of toe webbings in Rana for the last 12.0 Mya, most likely a useful key-trait for Rana species identification across northeast Asian. With the workflow for broad-scale species identification developed herein, we urge the development of trade monitoring and legislation on Rana species in northeast Asia.

Othman S. N., Shin Y., Kim H.-T., Chuang M.-F., Bae Y., Hoti J., Zhang Y., Jang Y. & Borzée A. (2022).Evaluating the efficiency of popular species identification analytical methods, and integrative workflow using morphometry and barcoding bioinformatics for taxonomy and origin of traded cryptic brown frogs.Global Ecology and Conservation. 38:e02253. DOI: 10.1016/j.gecco.2022.e02253

New publication through multiple collaborations including the description of Onychodactylus sillanus Yangsan Clawed Salamander (양산꼬리치레도롱뇽)!

For wildlife to be protected, it must first be known, as species that are not yet formally described are not the target of conservation attention, independently of threat levels. While habitat degradation has consistently increased across the last decades in the Republic of Korea, taxonomic and conservation efforts are lagging.

For instance, a clade of Onychodactylus clawed salamanders from the extreme southeast of the Korean Peninsula is known to have diverged circa 6.82 million years ago from its sister species O. koreanus, and despite the candidate species status of this lineage, its extremely restricted range is under intense anthropogenic pressure. Here, through the use of genetics, morphometrics and landscape modelling, we confirmed the species status of the southeast Korean Onychodactylus population and formally describe it as Onychodactylus sillanus (Yangsan Clawed Salamander; 양산꼬리치레도롱뇽).

We then proceed to determine threats, habitat loss and risk of extinction based on climatic models under different Representative Concentration Pathways and following the IUCN Red List categories and criteria. We highlight a decrease in the extent of occurrence between 87.6% and 97.3 % within the next three generations based on several climate change scenarios, a decline high enough for the species to be listed as Critically Endangered based on the category A3 of the IUCN Red List of species. Our results will enable the development of protection programs and legitimise citizen activities protecting the population. A conservation action plan is a priority to coordinate the activities linked to the protection of the species.

Borzée A., Shin Y., Poyarkov N. A., Jeon J. Y., Baek H. J., Lee C. H., An J., Hong Y. J., Min M-S. (2022).  Dwindling in the mountains: description of a critically endangered and microendemic Onychodactylus species (Amphibia, Hynobiidae) from the Korean Peninsula. Zoological Research. 43(5):750-755. DOI: 10.24272/j.issn.2095-8137.2022.048

New lab paper with collaborators describing a new Rhacophorid treefrog from Zhejiang in China! The species is named Kurixalus inexpectatus (Changxing Treefrog ; 长兴原指树蛙 ) following it’s unexpected presence in the region, a full 600 km further north than the closest related species – and across the sea!

The species diverged from its closest relative during the Late Pliocene to Pleistocene, ca. 3.06 Mya (HPD 95%: 5.82-0.01), based on calibrations with a relaxed clock species tree of unlinked mtDNA 12S rRNA and nuclear DNA TYR. The status of the newly-described species is also supported by a divergence in call properties and morphometrics. 

For more information on the backstory – and why we were looking for a totally different treefrogs, here is a fun read!

Most amphibians call but why do they call? Well, a male frog can call to attract a female or to defend his territory. As a part of the research, a team of scientists in Asia decided to study two elusive and syntopic species of balloon frogs – Marbled Balloon Frog and Indian Balloon Frog, and the findings of the study are published in BMC Zoology. Not much is known about their ecology and behaviour since they are highly secretive and spend most of their life underground. They surface only for a few days to breed. The research is also summarised in this video.

When breeding in same habitat, species may be forced to utilise the same habitat. This may increase the risk of cross breeding, which may result in unsuccessful reproduction. The researchers were interested to find ‘How do these two frog species overcome this problem and breed successfully?’. And they found that the two balloon frog species adapted to diverge in their acoustic behaviour by making a clear segregation in call properties. Helping them to distinguish their calls… making it easier to detect by females.

The two balloon frog species also used different calling locations within the same habitat. Creating a calling microhabitat partitioning. These strategies allowed them to breed successfully and help them co-exist!

Also, both the species have a potential of individual recognition through individual calls as shown in this research study.

Conclusion: This study provides the first detailed analysis of the vocal behaviour of elusive marbled balloon frog and Indian Balloon Frog and highlighting the potential for pre-mating isolation, character displacement and assortative mating in these two syntopic species. Leading to the association between acoustic and calling microhabitat niche as an important behavioural and ecological trait.

Prasad V. K., Chuang M-F., Das A., Ramesh K., Yi Y., Dinesh K P. & Borzée A. (2022). Coexisting good neighbours: acoustic and calling microhabitat niche partitioning in two elusive syntopic species of Balloon Frogs, Uperodon systoma and U. globulosus (Anura: Microhylidae) and potential of individual vocal signatures. BMC Zoology. 7:27. DOI: 10.1186/s40850-022-00132-x

Some good news from the Himalayas of Uttarakhand, India! Our lab member Vishal Kumar Prasad and his team and colleagues organised a major awareness and education program: ‘Saving Amphibians of Nainital Himalaya’ on 2^nd April 2022 for school students (age under 15) in Aarohi Peora, Nainital district. With the decline in covid-19 cases locally and further relaxation in restrictions, they were allowed to organise this program in villages.

The program included an interactive session on the research of endemic amphibians. Vishal presented his research work on the frogs and toads, natural history, importance, and threats the amphibians are facing in the Himalayan landscape. The team also organised some activities like memory games and the most exclusive the ‘FROG RACE!’ The winning team was awarded with prizes and certificates. All students enjoyed refreshments after a tiring ‘Frog Race’. Good teamwork was displayed by students in these group activities. This shows children are the hope for future conservation.

Interestingly, there was a pre-assessment of the existing knowledge of children about amphibians by providing them a questionnaire (10 questions). This activity will be monitored after imparting further knowledge to the children to see how their perspective has changed over a period of time.