Megophrys (Xenophrys) zhangi (Ye and Fei, 1992)

O, Kyle A., Connell, Aryal, Prakash C., Sherchan, Adarsh M., Dhakal, Bimala, Chaudhary, Hemanta Kumari, Ranabhat, Rishi & Karmacharya, Dibesh, 2019, A herpetological survey of the Kathmandu Valleyı Nepalı and phylogenetic identification of Megophrys (Xenophrys) zhangi, Journal of Natural History 53 (23), pp. 1421-1437 : 1428-1431

Megophrys (Xenophrys) zhangi

Figures 1 and 3 (d – g); Tables 2 , S 1 , S 2

specimens examined: CMDN-A 48 – 49, 56 – 59, 64 – 66, 83 – 85, 87 – 88, 98 – 101, 104 – 118, 129 – 150, 154, 164 – 165, 167 – 170.

Distribution in the KTM Valley: Encountered at all non-urban localities surveyed. Remarks: We encountered large numbers of Megophrys zhangi around the KTM Valley ( Table 2 ; Figure 1 ). This species was traditionally classified as Megophrys parva until Chen et al. (2017) assigned several Megophrys species to Xenophrys, including M. parva . Alternatively, Mahony et al. (2017) classified Xenophrys as a subgenus of Megophrys which is the arrangement we favour in this manuscript. Our phylogenetic analyses revealed a close phylogenetic affinity between Megophrys parva from the KTM Valley and M. zhangi ( Ye and Fei 1992) from the type locality ( Figure 5 ). The type locality of M. zhangi is Zhangmu, Xizang, China, close to the Nepal-China border in the foothills of the Himalayas ~ 55 km from KTM Valley. However, Mahony et al. (2018) found that this M. zhangi individual (sequenced by Chen et al. 2017) shared an identical 16s haplotype with one of their two M. monticola haplotype groups from Darjeeling (‘ mid-elevation mitochondrial haplotype group ’). Using nuclear sequence data, Mahony et al. (2018) show that the two haplotype groups of M. monticola represent a single species that exhibit deep divergence with M. zhangi . Mahony et al. (2018) suggest that the shared haplotype may represent mitochondrial capture between these sister species.

Thus, using 16s sequence we were unable to verify if the Nepalese sequences pertain to M. zhangi or M. monticola , though the geographic proximity to the M. zhangi type locality would support the former hypothesis. However, Mahony et al. (2018) differentiated M. zhangi (using the original description) from M. monticola based on a smaller SVL in the former. They state that in male specimens of M. zhangi (n = 3), SVL = 32.5 – 37.2 mm, compared with those of M. monticola (n = 17), SVL = 38.2 – 49.5 mm. SVL for the KTM Valley Megophrys range from 35 to 43.2 mm, overlapping the ranges given for the two species. However, the PCA of the 10 characters shared between our studies strongly separates the KTM Valley individuals from M. monticola , suggesting that the KTM Megophrys are on average much smaller ( Figure 5 (b)). For this reason, we reclassify Megophrys parva from the KTM Valley to M. zhangi . Because we only sequenced specimens from the KTM Valley, we suggest that other Megophrys species may be present in other regions of Nepal outside of the KTM Valley ( Mahony et al. 2018).

Megophrys zhangi was encountered on the banks of streams and around areas with running water ( Figure 3 (g)). While we usually observed them in intact habitats, they were also commonly encountered near disturbed areas with running water, but never in urban areas. Males called as early as 1600 during heavy rain but usually began calling at sundown (1900 in August). Females were found as far as 250 m from water, and always on the ground ( Figure 3 (e)). Males perched ~ 1 m above the water when calling, and always faced the water. At each locality males utilised different perch taxa ranging from bushes, to large rocks, to man-made structures ( Figure 3 (d,g)). This species was usually encountered in the same localities as Nanorana liebigii , but the two species were never observed in syntopy. At one locality in east Shivapuri, we encountered large numbers of larvae present in a shallow pool along with larvae and a juvenile of Duttaphrynus melanostictus ( Figure 3 (f)). Measurements: The mean, followed by the range in parenthesis is given for males (n = 26), followed by females (n = 2). SVL = 39.2 mm (35 – 43.2 mm), 43.8 mm (40 – 47.8 mm); HL = 12.4 mm (10.0 – 14.8 mm), 13.0 mm (11.2 – 14.8 mm); HW = 14.9 mm (12.0 – 17.0 mm), 15.8 mm (14.9 – 16.6 mm); snout = 4.1 mm (3.3 – 5.7 mm), 4.2 mm (3.7 – 4.7 mm); internarial = 5.0 mm (3.8 – 5.8 mm), 4.65 mm (4.6 – 4.7 mm); eye = 3.5 mm (2.5 – 4.5 mm), 4.35 mm (3.9 – 4.8 mm); tympanum = 2.1 mm (1.7 – 2.7 mm), 2.6 mm (2.5 – 2.7 mm); antebrachium = 8.7 mm (7.1 – 10.2 mm), 8.1 mm (7 – 9.2 mm); hand = 10.5 mm (9.2 – 12.0 mm), 12 mm; thigh = 15.2 mm (13.5 – 17.5 mm), 14.5 mm (12.9 – 16.1 mm); shank = 16.8 mm (14.4 – 18.8), 17.1 mm (15.2 – 19 mm); foot = 27 mm (23.7 – 29.3 mm), 28.4 mm (27.6 – 29.1 mm).

Figures

Figure 1. Map showing distributions of species surveyed in the Kathmandu Valley: circles = amphibians, squares = reptiles. Colours are defined as follows, amphibians: dark blue = Duttaphrynus melanostictus, purple = Nanorana liebigii, yellow = Fejervarya syhadrensis, light green = Hoplobatrachus tigerinus, dark green = Euphlyctis cyanophylyctis, orange = Megophrys (Xenophrys) zhangi, red = Microhyla ornata. Reptiles: light purple = Calotes versicolor, light blue = Hemidactylus platyurus, dark blue = Hemidactylus frenatus, dark purple = Herpetoreas platyceps.

Figure 3. Additional amphibian species observed during this survey. (a) Hoplobatrachus tigerinus, (b) Hoplobatrachus tigerinus, (c) Euphlyctis cyanophylyctis, (d) male Megophrys zhangi, (e) female (left) and male (right) of Megophrys zhangi, (f) tadpole of Megophrys zhangi, (g) male Megophrys zhangi calling on artificial substrate near water feature, (h) Microhyla ornata.

Figure 5. (a) Maximum likelihood phylogeny of Megophrys (Xenophrys). The mitochondrial 16S locus places Megophrys zhangi from the Kathmandu Valley as closely related to both M. zhangi from the type locality in Zhangmu, Xizang, China, and to one haplotype group of M. monticola. Nodes with higher than 75% bootstrap support are highlighted by gray circles. (b) Principal component analysis of external morphology comparing Megophrys monticola to Megophrys zhangi from the Kathmandu Valley. Results suggest smaller measurments on average for M. zhangi compared with M. monticola.