Blog

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!

An easy-to-read graphical summary of the findings of our recently published study on the acoustic behaviour of two syntopic balloon frogs species (also available on video). The balloon frogs of the genus Uperodon remain understudied for their behaviour and ecology due to their highly fossorial and secretive life. The focal species, the Marbled Balloon frog and the Indian Balloon frog, appear above ground for a short period to breed at the onset of monsoon season in the month of June and July in the Indian subcontinent.

The study provides 1) the first description of the vocal repertoire of Uperodon systoma and Uperodon globulosus, 2) demonstrates the divergence in the call properties between the two species, 3) describes partitioning in the calling microhabitat niche between the two species based on calling location of male frogs in the waterbody, 4) determine the individual recognition potential through individual vocal signatures for each species.

The study highlights the potential of pre-mating isolation, character displacement, and size-based assortative mating in the two syntopic fossorial frog species, leading to an association between acoustic, calling microhabitat niche and body index divergence as important behavioural and ecological traits.

Link of the research article: https://www.researchgate.net/publication/360725618_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_i/stats

Watch the promotional video: https://youtu.be/XQ5AaRGMpZo

Our short paper on Javan gibbon electrocution cases has been published in the Journal of Threatened Taxa. While most primate electrocution is reported in urban areas, we found three electrocuted gibbons in the wild during our long-term study.

Arboreal primates can easily access power lines, leading to immediate death in all cases we have. The last electrocution case was observed while drafting our manuscript, ensuring that this can continue if nothing is done for them.

Since the power lines often pass the forestry area, we suspect many more unreported cases of Javan gibbon or other wildlife death caused by electrocution. Prioritizing the high-risk area and managing conservation practices will be essential!

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Yi, Y., Ham, S., Oktaviani, R., Dewi, M.C., Nur, M., Mardiastuti, A. & Choe, J.C. (2022). Cases of fatal electrocution of the endangered Javan Gibbons (Mammalia: Primates: Hylobatidae) by power lines. Journal of Threatened Taxa, 14(5): 20964–2096. https://doi.org/10.11609/jott.7758.14.5.20964-20969