On the road to Mandalay: contribution to the Microhyla Tschudi, 1838 (Amphibia: Anura: Microhylidae) fauna of Myanmar with description of two new species

Abstract

We present a morphological and molecular assessment of the Microhyla fauna of Myanmar based on new collections from central (Magway Division) and northern (Kachin State) parts of the country. In total, six species of Microhyla are documented, including M. berdmorei , M. heymonsi , M. butleri , M. mukhlesuri and two new species described from the semi-arid savanna-like plains of the middle part of the Irrawaddy (Ayeyarwady) River Valley. We used a 2 481 bp long 12S rRNA–16S rRNA fragment of mtDNA to hypothesize genealogical relationships within Microhyla . We applied an integrative taxonomic approach combining molecular, morphological, and acoustic lines of evidence to evaluate the taxonomic status of Myanmar Microhyla . We demonstrated that the newly discovered populations of Microhyla sp. from the Magway Division represent two yet undescribed species. These two new sympatric species are assigned to the M. achatina species group, with both adapted to the seasonally dry environments of the Irrawaddy Valley. Microhyla fodiens sp. nov. is a stout-bodied species with a remarkably enlarged shovel-like outer metatarsal tubercle used for burrowing and is highly divergent from other known congeners ( P -distance≥8.8%). Microhyla irrawaddy sp. nov. is a small-bodied slender frog reconstructed as a sister species to M. kodial from southern India ( P -distance=5.3%); however, it clearly differs from the latter both in external morphology and advertisement call parameters. Microhyla mukhlesuri is reported from Myanmar for the first time. We further discuss the morphological diagnostics and biogeography of Microhyla species recorded in Myanmar.

A little frog leaps a long way: compounded colonizations of the Indian Subcontinent discovered in the tiny Oriental frog genusMicrohyla(Amphibia: Microhylidae)

“…(Wogan et al, 2008;Peloso et al, 2016), or M. cf. berdmorei , clearly belongs to this group and forms a highly divergent lineage (Poyarkov et al, 2019). We also agree with in recognizing this species group as distinct from the M. achatina group, though monophyly of the latter is only moderately supported (Fig.…”

Acoustic divergence in advertisement calls among three sympatricMicrohylaspecies from East China

“…To the best of our knowledge, the present study is the first to report the advertisement call of M. beilunensis consisting of 2-7 pulses per call, which has relatively few NPs among the 29 studied Microhyla species. Similar to that in other Microhyla species reported previously (Wijayathilaka, Meegaskumbura & Gianni, 2016;Sun, 2017;Nguyen et al, 2019;Poyarkov et al, 2019;Garg et al, 2018), oscillograms and spectrogram of advertisement calls in M. beilunensis were conformed to the pulse-repetition sound based on Beeman's (1998) sound categories. The patterns of variation in call parameters of anurans are correlated with female preferences and different parameters contain different kinds of biologically significant information (Gerhardt, 1991).…”

“…For example, behavioral traits are often more highly modified than physiological features (Blomberg, Garland & Ives, 2003;Mclean, Bishop & Nakagawa, 2013). Several Microhyla species are sympatric (Lee et al, 2016;Poyarkov et al, 2019;Frost, 2020;Z.-Q. Chen et al, 2019, unpublished data).…”

“…Advertisement calls are a form of male anuran vocalization that is most commonly heard and of the highest value in taxonomy and they play a crucial role in attracting potential mates and conveying territorial information to conspecifics. Several researchers have focused on advertisement calls of anurans (Wells, 2007;Gambale, Signorelli & Bastos, 2014;Köhler et al, 2017;Poyarkov et al, 2019;Wei et al, 2019). The variation in advertisement calls in anurans is generally studied at the intraspecific and interspecific levels (Köhler et al, 2017).…”

“…To date, there are reports on the advertisement calls of 28 Microhyla species (Table S1). Several studies have reported the taxonomy and identification of Microhyla species in some distribution areas (Sri Lanka, Myanmar and South Asia) through bio-acoustic comparison (Wijayathilaka, Meegaskumbura & Gianni, 2016;Garg et al, 2018;Poyarkov et al, 2019). In East China, M. beilunensis Zhang et al (2018), M. fissipes Boulenger (1884) and M. heymonsi Vogt (1911) are three common Microhyla species and their distribution ranges are overlapping (Fig.…”