Allopaa hazarensis, (Dubois & Khan, 1979)

Hofmann, Sylvia, Schmidt, Joachim, Masroor, Rafaqat, Borkin, Leo J, Litvintchuk, Spartak, Rödder, Dennis, Vershinin, Vladimir & Jablonski, Daniel, 2023, Endemic lineages of spiny frogs demonstrate the biogeographic importance and conservational needs of the Hindu Kush-Himalaya region, Zoological Journal of the Linnean Society 198 (1), pp. 310-325 : 319

GENETIC DIVERSITY OF ALLOPAA HAZARENSIS

In contrast to the deeply divergent clades in the phylogeny of the spiny frogs, genetic diversity of Allopaa hazarensis across its known range is small and without a clear distribution pattern of haplotypes, according to their geographic origin. Major haplotypes are present at multiple localities. However, the Indus seems to act as physical barrier, limiting gene flow between populations. The relatively high haplotype and low nucleotide diversity suggest a recent expansion of the species. This is supported by the higher number of unique haplotypes in relation to all haplotypes ( Slatkin & Hudson, 1991; Fu, 1997), although this is influenced by sample sizes. Most likely, all of these haplotypes originated from the respective predominant ancestral haplotypes after the expected population expansion. Such a pattern and interpretation has been reported before for other amphibians ( Garcia-Gonzalez et al., 2012; Greenwald et al., 2020). Overall, neither genetic distances, nor haplotype networks and nucleotide variability indicate potential cryptic diversity within A. hazarensis . In general, the networks suffer from the low number of sampling sites and, therefore, we consider these results only as preliminary. Because amphibians are predominantly site-loyal and of low vagility ( Vences & Wake, 2007; da Fonte et al., 2019), and since Allopaa is highly adapted for a semi-aquatic lifestyle in mountain streams, we assume that colonization by A. hazarensis is mainly facilitated through (small) aquatic corridors (e.g. by rafting), not via terrestrial dispersal routes. Movement of A. hazarensis in natural habitats has recently been addressed using radio transmitters, suggesting almost no overland dispersal ( Akram et al., 2022) and movement distances of only a few meters. However, in this study data collection was limited to only eight days in September, and almost 40% of the transmitters were lost during that time, rendering the results less conclusive.

Noteworthy, according to some authors [e.g. Frost (2022) and references therein], the genus Allopaa consists of two species, A. hazarensis and Allopaa barmoachensis (Khan & Tasnim, 1989) , the latter originally described as Rana barmoachensis Khan & Tasnim, 1989 . Based on morphological examination of the holotype, Dubois (1992) and repeatedly Ohler and Dubois (2006) considered this taxon as a junior synonym of hazarensis (as Paa ). Given these data, as well as the geographical proximity of the type locality of A. barmoachensis to the main distribution range of A. hazarensis (and an even similar elevation of the species records), we tentatively agree with the opinion that A. barmoachensis is a synonym of A. hazarensis . However, molecular and additional morphological data are required to verify that conclusion.