Revisited Molecular Phylogeny of the Genus Sphaerotheca (Anura: Dicroglossidae): The Biogeographic Status of Northernmost Populations and Further Taxonomic Changes

Abstract

Heretofore, the populations of the genus Sphaerotheca Günther, 1859 (Dicroglossidae) in their northern and western borders laying in Pakistan have been assigned to two species, S. breviceps (Schneider, 1799) and S. strachani (Murray, 1884). The genus has origin in the Oriental zoogeographic region and comes to close geographic proximity with the Palearctic region in Pakistan. The recent molecular studies have on one hand restricted the distribution range of S. breviceps to the eastern coastal plains of India and, on the other hand, revealed the northern- and westernmost population in India as a separate species, S. pashchima Padhye et al., 2017. This species has recently been synonymized with S. maskeyi (Schleich and Anders, 1998). These taxonomic changes, however, warranted the need for validation of Pakistani Sphaerotheca based on genetic data. We sequenced and analyzed 16S rRNA mitochondrial gene from specimens originating from the Himalayan foothills of Pakistan and compared these with all available GenBank sequences of the genus. Based on this data, we conclude that the Himalayan foothills of Pakistan are occupied by S. maskeyi. Simultaneously, we bring the first record of this species for the Palearctic region. We further suggest that more genetic material from across Pakistan is required to ascertain the validity of S. strachani and for the phylogeographic evaluation of western and northern border populations of the genus. Our geographically wide and revisited molecular phylogeny shows that the genus exhibits genetic diversity suggesting further taxonomic changes. The low level of genetic divergences between S. breviceps and S. magadha Prasad et al., 2019 compared to other species of the genus, indicates that the taxonomic status of S. magadha is questionable. Moreover, we found that S. magadha and S. swani (Mayers and Leviton, 1956) are genetically conspecific with S. breviceps and both should be thus considered as its junior synonyms. On the other hand, S. dobsonii and populations from Myanmar need further detailed investigations.

An insight into molecular taxonomy of bufonids, microhylids, and dicroglossid frogs: First genetic records from Pakistan

“…However, genetic distance between S. pashchima and S. breviceps was 6.4% (TablesS5 and S6). Our results are in congruent with successive studies ofPadhye et al (2017),Jablonski et al (2021), andKhatiwada et al (2021), and we believe the presence of S. maskeyi (synonym:S.…”

“…( 2020 ) on genus Euphlyctis , Jablonski et al. ( 2021 ) on genus Sphaerotheca, and Hofmann et al. ( 2021 ) on genus Allopaa .…”

“…Sphaerotheca pashchima differs from S. breviceps by minor differences such as rounded snout, second finger length equal to or less than fourth finger length; first finger length less than third finger(Padhye et al, 2017) Khatiwada et al (2021). declared S. pashchima as a synonym of S. maskeyi(Schleich and Anders, 1998) Jablonski et al (2021). also designated this species as S. maskeyi, from Himalayan foothills of Pakistan, based on two genetic samples collected from Khyber Pakhtunkhwa Province, Pakistan.…”

The genus Pelophylax (Amphibia, Ranidae) in Pakistan: museum collections and possible distribution

“…As there exist no recent observations on Pelophylax from Pakistan and only four exact localities are historically known with only two corroborated by available voucher specimens, it is difficult to evaluate if Pelophylax is currently a member of the herpetofauna of the country. According to Masroor (2012), Sarwar et al (2016), Frost (2021 and Jablonski et al (2021), 20 to 24 species of amphibians are currently reported from the country, without any mention of the family Ranidae or the genus Pelophylax. Pakistani Balochistan is herpetologically the most diverse region of the country (Khan 2006), yet the predominantly arid conditions do not generally provide suitable and stable habitats for amphibians.…”

“…Pakistan is a country in the transition zone between the Palearctic and Oriental faunas, which is based on the fact that representatives of (not only) amphibians from both these two zoogeographic regions may be found in the country (Khan 2006;Jablonski et al 2020Jablonski et al , 2021. Currently, the territory of Pakistan contains four families of amphibians: Bufonidae Gray, 1825; Dicroglossidae Anderson, 1871;Megophryidae Bonaparte, 1850;andMicrohylidae Günther, 1858 (Masroor 2012;Sarwar et al 2016;Frost 2021).…”