Megophrys (Panophrys) fansipanensis, 2018

Tapley, Benjamin, Cutajar, Timothy, Mahony, Stephen, Nguyen, Chung Thanh, Dau, Vinh Quang, Luong, Anh Mai, Le, Dzung Trung, Nguyen, Tao Thien, Nguyen, Truong Quang, Portway, Christopher, Luong, Hao Van & Rowley, Jodi J. L., 2018, Two new and potentially highly threatened Megophrys Horned frogs (Amphibia: Megophryidae) from Indochina’s highest mountains, Zootaxa 4508 (3), pp. 301-333 : 307-316

Megophrys (Panophrys) fansipanensis sp. nov.

Figs. 1 , 3–7 & Table 2.

Holotype: Adult male ( VNMN 2018.01 ), found perched on a stick 3 m above a 2 m wide low-gradient stream in disturbed evergreen forest on Mount Fansipan , Hoang Lien National Park ( HLNP), Sa Pa District, Lao Cai Province, Vietnam (22.32827° N, 103.78184° E, 2242 m asl; Fig. 1 ), collected at 19:15 h on 12 June 2012 by Jodi J. L. Rowley, Dau Quang Vinh, Pham Van Sang, Tran Van Tu, Hang A Su, Hoang A Di and Dinh Van Xuan.

Paratypes: Adult female ( VNMN 07033 ), found resting on leaf litter associated with bamboo forest beside a 1 m wide cascading stream on Mount Fansipan , HLNP, Sa Pa District, Lao Cai Province, Vietnam (22.31458° N, 103.76574° E, 2783 m asl; Fig 1 ), collected at 20:00 h on 0 9 June 2012 ; four adult males ( AMS R186105–08 ), found in the vicinity of a 1 m wide cascading stream on Mount Fansipan , HLNP, Sa Pa District, Lao Cai Province, Vietnam (22.31349° N, 103.76521° E, 2813 m asl; Fig. 1 ), on 10 June 2012 ; four adult males ( AMS R186109–12 ), collected at the same location as the holotype on 13 June 2012 ; one adult male ( AMS R186113 ), collected near the type locality, beside a 2 m wide swiftly cascading stream (22.31387° N, 103.7654° E, 2793 m asl; Fig 1 ), collected on 11 June 2012 . All aforementioned specimens collected by Jodi J. L. Rowley, Dau Quang Vinh, Pham Van Sang, Tran Van Tu, Hang A Su, Hoang A Di and Dinh Van Xuan. A gravid female ( AMS R186116 ) and two calling adult males ( AMS R186114 & AMS R186115 ), collected from disturbed bamboo and elfin forest near a steep rocky stream on Mount Fansipan , HLNP, Sa Pa District, Lao Cai Province, Vietnam, (22.31412° N, 103.76588° E, 2764 m asl; Figs. 1 & 6C ), collected between 20:15 and 20:20 h on 21 June 2016 by Jodi J. L. Rowley, Benjamin Tapley and Nguyen Thanh Chung .

Referred specimen: One adult male (HLNP 20120620 00002), found resting on leaf litter within a bamboo forest beside a 1 m wide cascading stream on Mount Fansipan, HLNP, Sa Pa District, Lao Cai Province, Vietnam (22.31349° N, 103.76521° E, 2813 m asl; Fig. 1 ), collected on 10 June 2012 by Jodi J. L. Rowley, Dau Quang Vinh, Pham Van Sang, Tran Van Tu, Hang A Su, Hoang A Di and Dinh Van Xuan.

Etymology: Specific epithet “ fansipanensis ” is a toponym in reference to the type locality of the species, meaning “from [Mount] Fansipan”.

Suggested vernacular name: Mount Fansipan horned frog (English), Ếch sừng phan xi păng (Vietnamese).

Diagnosis: Megophrys fansipanensis sp. nov. differs from its congeners by a combination of the following morphological characters: (1) small size, adult male SVL 30.9–44.3 mm (N =13), adult female SVL 41.7–42.5 mm (N =2); (2) small palpebral horn on upper eyelid; (3) toes lacking distinct interdigital webbing and lateral dermal fringes indistinct or absent; (4) TYD/EL 53.0–80.0% in adult males (N =13), 63.0–71.0% in adult females (N =2); (5) subarticular tubercles absent; (6) palmar tubercles absent; (7) inner metatarsal tubercle present; (8) SHL/SVL 49.0–58.9% in adult males (N =13), 55.8–58.5% in adult females (N =2); (9) tympanum clearly defined; (10) vomerine ridges, vomerine and maxillary teeth present; and (11) an advertisement call with an average dominant frequency of 3.8 kHz at 15.3–18.3 °C.

Description of holotype (measurements provided in Table 2): Sexually mature male ( Figs. 3 A–B, 4A–C, 5A & 5D). Head small, longer than wide; snout rounded in dorsal view, obtusely protruding in lateral view, rostral appendage absent; loreal region vertical and concave; canthus rostralis angular; dorsal region of the snout slightly concave; eye length 33% greater than the maximum diameter of the tympanum and subequal to the snout length; eye to tympanum distance shorter than the maximum tympanum diameter; tympanum circular. Pupil in life oval, vertically orientated when dilated; nostrils orientated laterally, equidistant to the eyes and the snout; internarial distance is less than the width of the upper eyelids, and less than the narrowest point between the upper eyelids; upper eyelid width and the shortest distance between the upper eyelids are subequal to one another. Vomerine ridges present, oblique and barely separated anteriorly, with small vomerine teeth; maxillary teeth present. Tongue moderately large and not clearly notched posteriorly. Forelimbs moderately long and thin, forearm length shorter than the hand length; fingers long and narrow, without lateral fringes, finger length formula FI<FII<FIV<FIII; interdigital webbing, and subarticular, supernumerary and palmar tubercles absent; thenar tubercle weak; finger tips slightly expanded relative to the adjacent digit width and flattened to oval pads; terminal grooves absent. Hindlimbs relatively long and thin; thigh length shorter than the shank length, and shorter than the foot length; toes long and rounded in cross section without dermal fringes, toe tips slightly dilated relative to the adjacent digit width and flattened to oval pads, terminal grooves absent; toes not webbed; outer metatarsal, subarticular and supernumerary tubercles absent; inner metatarsal tubercle very weakly defined.

Skin of the dorsal surfaces of the body, limbs and dorsal and lateral surfaces of the head weakly granular; tympanum granular with borders slightly raised; very small palpebral horn present on the outer edge of the upper eyelids; supratympanic fold narrows as it passes above the tympanum and expands in width again posteriorly, terminating above the axilla; flanks with small scattered tubercles; thin dorsolateral fold on each side, extending from behind the supratympanic fold to approximately two-thirds of the distance to the groin; a weak, “V”-shaped parietoscapular ridge present, its two sides extending posteriorly from above the tympanum and meeting medially beyond the level of the axilla; a second inverted “V”-shaped sacral ridge present on the mid-dorsum which joins laterally with the dorsolateral folds; “V”-shaped ridges joined at their apices by a medial ridge; small tubercles arranged into distinct transverse rows on the dorsal surfaces of thighs, shanks and forearms. Large distinct tubercles present on the inguinal region; gular region, chest and ventral surfaces of the limbs smooth; pectoral glands distinct, small, slightly raised, positioned level with the axilla; femoral glands small, slightly raised, one positioned equidistant from the knee and cloaca on the posterior surface of each thigh; white skin asperities form a narrow band circummarginally on the upper and lower jaw; black asperities on the tubercles of the tympanic regions and posterior parts of the upper eyelids, absent elsewhere.

Colour of holotype: In life ( Fig. 5A & 5D ): Dorsally dark tan; darker lines follow the opposing “V”-shaped parietoscapular-sacral ridges; dark brown loreal region, snout pale; darker brown triangular marking between the eyes with a lighter central blotch; vertical dark brown bar below the eyes; dark brown tympanum; dark tan hind and forelimbs possess dark bars; supratympanic fold longitudinally bicolored, cream above and dark brown below; tubercles in the inguinal region either a pale cream or dark brown in colour; gular and pectoral region dark greybrown, gular region with a medial dark brown stripe; abdomen lighter with dark blotches and speckling; ventral surface of the thighs speckled with brown; iris metallic orange with black reticulations throughout.

In preservative ( Figs. 3 A–B & 4A–C): The majority of the dorsal and lateral surfaces of the head, body, forelimbs and hindlimbs brown; darker brown triangular marking with light central blotch between the eyes; darker brown “X”-shaped marking over the opposing “V”-shaped parietoscapular-sacral ridges; dorsolateral and supratympanic folds and flank tubercles brownish-cream; the front of the snout and the lateral canthus rostralis dark brown; wide vertical dark brown bar below the eyes; dark brown tympanum; two dark brown blotches on the anterior lateral surface of the forearms; dorsal surface of FII, FIII, FIV with dark brown blotches. The gular region, chest and the anterior part of the abdomen primarily creamy-grey, with brown speckling on the gular region; gular region with a medial dark brown stripe. Abdomen blotched with dark brown, large brown blotches incompletely encircle the abdomen; ventral surfaces of the thighs and shanks with pale brown mottling; ventral surfaces of the feet grey-brown; area surrounding the vent dark brown; forelimbs ventrally mottled and blotched with light and dark brown; ventral surface of the hands grey; pectoral and femoral glands white. Refer to Figures 3 A–B, 4A–C, 5A & 5D for further details of markings and colouration.

Variation: Morphometric measurements of the type series and referred specimen are given in Table 2. Paratypes and the referred specimen generally agree with the holotype morphologically, but with the following exceptions: Head width greater than the head length for 11 of the 15 specimens (VNMN 0 7033, AMS R186106¯10, AMS R186112, AMS R186113, AMS R186115, AMS R186116 & HLNP 20120620 00002); head width less than the head length for two specimens (VNMN 2018.01 & AMS R186105), and head length equal to the head width for two specimens ( AMS R186111 & AMS R186114 ) . Seven of the 15 specimens ( VNMN 2018.01 , AMS R186106 & AMS R186109 ¯13) lack dermal fringes on the toes whereas indistinct ridges were observed on the toes of five specimens ( VNMN 0 7033, AMS R186105 , AMS R186107 , AMS R186108 & HLNP 20120620 00002). It is not clear if the presence of indistinct ridges on the toes of these specimens is an artefact of specimen positioning during the fixation process. Relative finger lengths differ from the holotype as follows :

FI<FIV<FIII<FII (AMS R186107); FI<FIVẼFIII<FII (AMS R186109); FI<FIIẼFIV<FIII (AMS R1 86108 & AMS R186112); and FIẼFII<FIV<FIII (AMS R186113). The tongue of the holotype is not clearly notched posteriorly, but several specimens in the series (VNMN 0 7033, AMS R186105¯6, AMS R186109 & AMS R186111¯3) appeared to have notched tongues posteriorly. The absence of a notch may be an artefact of fixation. Colouration in life is highly variable, one female specimen being a uniform brick red on the dorsal surface (VNMN 07033; Figs. 5B, 5C, 5E & 5H ). Most specimens in the series have opposing “V”-shaped parietoscapular and sacral ridges but two specimens (AMS R186113, Fig. 5F ; VNMN 0 7033, Fig. 5C ) have only the “V”-shaped parietoscapular ridge and lack sacral ridges. The underside of the thighs are blotched or speckled with brown on some specimens ( Fig. 5 H–J).

Secondary sexual characters: All males had slightly raised nuptial pads covered with black microspinules; nuptial pads covering most of the dorsal surface of the base of FI and FII; nuptial pad oval shaped on FI and FII; a protruding fleshy projection posterior to the cloaca (a secondary sexual character of some male Megophrys , e.g., M. caudoprocta Shen, 1994 , M. koui and M. pachyproctus ) is absent on all male specimens. Female (AMS R186116) with large unpigmented ova; both examined females did not possess nuptial pads or dermal asperities.

Molecular data: 16S sequences were generated from three adult specimens. Uncorrected p -distance between Megophrys fansipanensis sp. nov. and other Megophrys sequences available on GenBank were ±3.3%.

Advertisement call: Call descriptions are based on the call groups of the holotype (VNMN 2018.01, N= 3) and two paratypes (AMS R186114 [N= 12] & AMS R186115 [N= 5]), and the total number of calls analysed (N =60) was 20 calls per individual. Advertisement calls were recorded at 15.3–18.3 °C ambient temperature. Calls were an average of 42 ms (34–49 ms) in duration ( Table 3, Fig. 7 ). Calls contained an average of 11.6 pulses (10–14). The average dominant frequency of all analysed calls was 3.8 kHz (3.6–4.7 kHz). Calls were repeated at a rate of 3.9 (3.8–4.0) calls per second in the analysed call groups and had an average intercall interval of 204.4 ms (180–290 ms). The number of calls within each call group ranged from 1 to 41, with an average of 22.8. Most call groups began with one to three calls at relatively low amplitude, with amplitude increasing with each call, after which amplitude remained relatively constant ( Fig. 7 ). Individual calls decreased in amplitude over time ( Fig. 7 ).

Natural history: Megophrys fansipanensis sp. nov. is associated with upper montane bamboo forest, mixed bamboo forest and disturbed secondary broadleaf forest with a relatively open canopy. All individuals have been encountered at night and found in riparian habitat along 1–2 m wide streams with clear water and rocky stream beds. The majority of individuals were encountered in the month of June, fewer animals were observed in September. Males were calling from stream-side vegetation in June 2012 and June 2016. A gravid female was found adjacent to a fast-flowing stream in June 2016. Tadpoles were not observed at this time. During field work in September 2015, only a single unvouchered male was encountered, no vocalisations were heard and tadpoles were not observed.

AMS R186115 VNMN 2018.01 AMS R186114

Number of call groups measured 5 3 12

Number of calls measured 20 20 20

Call duration (ms) 41.2 (38–45) 43.8 (41–49) 40.8 (34–45)

Intercall interval (ms) 213.7 (197–245) 197.7 (180–227) 201.8 (168–290)

Call repetition rate (calls/s) 3.8 4.0 4.0

Calls/call group 22.2 (18–25) 34.7 (24–41) 11.4 (1–22)

Pulses/call 11.1 (10–12) 10.8 (10–11) 12.9 (12–14)

Dominant frequency (kHz) 3.6 (na) 3.9 (3.9–4.1) 4.0 (3.6–4.7)

Temperature (°C) 15.3 18.3 15.3

Distribution and conservation status: Megophrys fansipanensis sp. nov. is only known from Mount Fansipan at elevations between 2200 and 2813 m asl ( Fig. 1 ). We did not detect this species during field work on Mount Fansipan at elevations of 1200 m asl (June 2016), 1700 m asl (June 2012 & 2016) and 1900 m asl (June 2016; September 2017). The high elevation sites where this species occurs face the immediate threat of habitat degradation and pollution due to the impact of tourists; habitats were noticeably polluted with garbage and runoff from toilets near the stream ( Fig. 6D ). In addition, if Megophrys fansipanensis sp. nov. is restricted to a narrow, high-elevation band, then the species is likely to be particularly vulnerable to climate change. Megophrys fansipanensis sp. nov. may occur more widely, but it was not detected in habitat similar to that found on Mount Fansipan during recent surveys on Mount Ky Quan San, 25 km north of our collection sites. The current EOO is predicted to be 630 km 2, qualifying Megophrys fansipanensis nov. sp. for listing as Endangered in accordance with the IUCN Red List of Threatened Species categories and criteria B1ab(iii).

Comparisons: Megophrys fansipanensis sp. nov. can be distinguished from all species in the subgenus Panophrys found in mainland Southeast Asia, north of the Isthmus of Kra and neighbouring provinces of China on the basis of morphology, and from all species in the subgenus for which comparable data is available on the basis of molecular and acoustic data. Comparisons with each subgenus are discussed separately below. The following comparison is based on 13 males and two females of Megophrys fansipanensis sp. nov.

Subgenus Brachytarsophrys : Megophrys fansipanensis sp. nov. can be distinguished from M. carinense , M. feae and M. intermedia by the absence of a transverse fold at the base of the head (versus presence in M. carinense , M. feae and M. intermedia ) and having a smaller adult male size, SVL 30.9–44.3 mm (versus SVL> 79.1 mm; material examined).

Subgenus Ophryophryne : Megophrys fansipanensis sp. nov. can be distinguished from all species in the subgenus Ophryophryne due to the presence (versus absence) of maxillary teeth ( Poyarkov et al. 2017; material examined) and further from M. elfina by having a larger adult female size, SVL 41.7–42.5 mm (versus 35.1–36.5 mm, N =6, in M. elfina ; Poyarkov et al. 2017) and the presence of vomerine teeth (versus absence in M. elfina ; Poyarkov et al. 2017); from M. gerti by having a smaller adult female size, SVL 41.7–42.5 mm (versus 43.1–47.4 mm, N =3, in M. gerti ; Poyarkov et al. 2017; material examined) and the presence of vomerine ridges and teeth (versus absence in M. gerti ; Poyarkov et al. 2017); from M. hansi by having a smaller adult female size, SVL 41.7– 42.5 mm (versus 45.1–53.9 mm, N =5, in M. hansi ; Poyarkov et al. 2017; material examined); from M. koui by the absence of a protruding fleshy projection above the cloaca in sexually mature males (secondary sexual characteristic of sexually mature M. koui ; Poyarkov et al. 2017); and from M. synoria by having a smaller adult female size, SVL 41.7–42.5 mm (versus 51.4–70.7 mm, N =3, in M. synoria ; Poyarkov et al. 2017) and the presence of microspinules on nuptial pads of sexually mature males (versus microgranules on nuptial pads of sexually mature male M. synoria ; material examined).

Subgenus Xenophrys : Megophrys fansipanensis sp. nov. differs from M. auralensis by having a smaller adult male size, SVL 30.9–44.3 mm (versus 60.1¯ 76.9 mm, N =20, in M. auralensis ; Ohler et al. 2002; Neang et al. 2013); from M. damrei by having a smaller adult male size, SVL 30.9–44.3 mm (versus 47.7–57.1 mm, N =7, in M. damrei ; Mahony 2011; Neang et al. 2013; material examined); from M. glandulosa by having a smaller adult male size, SVL 30.9–44.3 mm (versus 76.7–81.6 mm, N =10, in M. glandulosa ; Fei et al. 2009; material examined), a lack of dermal fringes on toes (versus presence in M. glandulosa ; Huang et al. 1998; Mahony et al. in press), a lack of distinct interdigital webbing between toes (versus basal webbing in M. glandulosa ; material examined), and the absence of a light-coloured upper lip stripe (versus presence in M. glandulosa ; Fei et al. 1990; Mahony et al. in press); from M. lekaguli by having a smaller adult male size, SVL 30.9–44.3 mm (versus 55.6–68.1 mm, N =8, in M. lekaguli ; Stuart et al. 2006b; material examined); from M. major by having a smaller adult male size, SVL 30.9–44.3 mm (versus 72.4–79.4 mm, N =5, in M. major ; material examined), a lack of distinct interdigital toe webbing (versus at least one quarter webbed in M. major ; Boulenger 1908; Mahony et al. in press; material examined), and the absence of a light-coloured upper lip stripe (versus presence in M. major ; Boulenger 1908; Mahony et al. in press; material examined); from M. maosonensis by having a smaller adult male size, SVL 30.9– 44.3 mm (versus 58.0–76.0 mm, N =6, in M. maosonensis ; Bourret 1937), a lack of distinct interdigital toe webbing (versus toes up to one quarter webbed in M. maosonensis ; Bourret 1937) and the absence of a light-coloured upper lip stripe (versus presence in M. maosonensis ; Bourret 1937); from M. pachyproctus by a larger tympanum to eye ratio, TYD/EL 53.0–80.0% (versus 29.0%, N =3, in M. pachyproctus ; Huang et al. 1981) and the absence of a protruding projection posterior to cloaca on male specimens (versus presence in M. pachyproctus Huang et al. 1981 ); from M. parva by a larger tympanum to eye ratio, TYD/EL 53.0–80.0% (versus 43.5–56.0%, N =6, in M. parva ; material examined); and from M. takensis by having a smaller adult male size, SVL 30.9–44.3 mm (versus 47.3–53.0 mm, N =3, in M. takensis ; Mahony 2011).

Subgenus Panophrys : Phylogenetic analysis places this new species in the subgenus Panophrys . Megophrys fansipanensis sp. nov. differs from M. binchuanensis by the absence of subarticular tubercles (versus presence in M. binchuanensis ; Ye & Fei 1995) and lateral fringe on toes absent (versus presence in M. binchuanensis ; Ye & Fei 1995); from M. boettgeri by the presence of vomerine ridges and teeth (versus absence in M. boettgeri ; Boulenger 1899; material examined), and male advertisement call (see Bioacoustic comparison); from M. brachykolos by subarticular tubercles on fingers absent (versus present on the base of all fingers in M. brachykolos ; Inger & Romer 1961; material examined) and vomerine ridges and teeth present (versus absent in M. brachykolos ; Inger & Romer 1961; material examined); from M. daweimontis by the absence of palmar tubercles (versus distinct and red in life in M. daweimontis ; Rao & Yang 1997); from M. jingdongensis by having a smaller adult male size, SVL 30.9–44.3 mm (versus 53.0– 56.5 mm, N= 3, in M. jingdongensis ; Fei et al. 2012; Li et al. 2014), and a lack of wide dermal fringes on the toes and lack of distinct interdigital webbing between the toes (versus dermal fringes on toes and toes being at least one quarter webbed in M. jingdongensis ; Fei and Ye 1983); from M. latidactyla by a lack of distinct interdigital webbing between the toes (versus at least one quarter webbed in M. latidactyla ; Orlov et al. 2015), absence of dermal fringe on the toes (versus wide dermal fringes in M. latidactyla ; Orlov et al. 2015), and a single palpebral horn (versus a series of palpebral horns in M. latidactyla ; Orlov et al. 2015); from M. minor by the presence of vomerine teeth (versus absence in M. minor ; Stejneger 1926), adult male TYD/EL 53.0–80.0% (versus 47–48%, N= 2, in M. minor ; material examined), and male advertisement call (see Bioacoustic comparison); from M. omeimontis by having a smaller adult male size, SVL 30.9–44.3 mm (versus 51.6–60.9 mm, N= 5, in M. omeimontis ; material examined), and the absence of distinct dermal fringes on toes (versus presence in M. omeimontis ; material examined); from M. palpebralespinosa by the absence of dermal fringes on the toes (versus presence in M. palpebralespinosa ; Bourret 1937; material examined), the absence of extensive interdigital webbing between the toes (versus presence in M. palpebralespinosa ; Bourret 1937; material examined), and the presence of a small palpebral horn like structure on upper eyelids (versus moderately large in M. palpebralespinosa ; Bourret 1937; material examined); from M. rubrimera by having a larger adult size, male SVL 30.9–44.3 mm, female SVL 41.7–42.5 mm (versus male SVL 26.7–30.5 mm, N =8, female SVL 26.6–30.8 mm, N =4, in M. rubrimera ; material examined), lateral fringes on toes absent (versus present in M. rubrimera ; material examined), the absence of a redorange groin, inner thigh and outer surface of shank in life (versus presence in M. rubrimera ; Tapley et al. 2017a), and male advertisement call (see Bioacoustics comparison); from M. spinata by the absence of distinct interdigital webbing between the toes (versus distinctly webbed in M. spinata ; Hu et al. 1973), and an absence of large keratinised spines on the nuptial pads of sexually mature males (versus presence in sexually mature male M. spinata ; Hu et al. 1973); from M. wuliangshanensis by having a larger tympanum on males, mean male TYD/EL 58.6%, N =13 (versus mean male TYD/EL 48.8%, N =10, in M. wuliangshanensis ; Ye & Fei 1995), a longer SHL on females, mean female SHL/SVL 57.2%, N =2 (versus mean female SHL/SVL 50.4%, N = 2 in M. wuliangshanensis ; Ye & Fei 1995), and the presence of vomerine ridges and vomerine teeth (versus absence in M. wuliangshanensis ; Fei et al. 2009, 2012).

From species not yet assigned to a subgenus: Megophrys fansipanensis sp. nov. differs from M. feii by having a larger adult male body size, SVL 30.9–44.3 mm (versus 24.3–25.1 mm, N =4, in M. feii ; Yang et al. 2018), the presence of vomerine ridges and vomerine teeth (versus absence in M. feii ; Yang et al. 2018), by the absence of lateral fringes on toes (versus presence in M. feii ; Yang et al. 2018), by the presence of nuptial pads on the fingers of breeding males (versus absence in M. feii ; Yang et al. 2018), and the absence of a protruding projection posterior to the cloaca (versus present in both sexes of M. feii ; Yang et al. 2018).

Bioacoustic comparison: The male advertisement call of this new species differs from those of its three congeners (subgenus Panophrys ) found in mainland Southeast Asia, north of the Isthmus of Kra and neighbouring provinces of China for which calls have been described. The male advertisement call of Megophrys fansipanensis sp. nov. recorded at 15.3–18.3 °C differs from M. boettgeri (data from Wang et al. 2014 based on recordings made at 15.0–18.0 °C) by having an average call duration of 41.9 (34–49) ms, N =60 (versus average 54 ms, N= 76, in M. boettgeri ), and lacking clear harmonics (versus relatively clear harmonics at approximately 5 kHz in M. boettgeri ); from M. minor (data from Jiang et al. 2001 based on recordings made at 14 °C) by having a dominant frequency of 3.6–4.7 kHz, N =60 (versus 3.4–3.5 kHz, N =10, in M. minor ), a call duration of 34–49 ms, N =60 (versus 75–110 ms, N =14, in M. minor ), a call repetition rate of 3.92 (3.82–3.97) calls/s, N =60 (versus average 4.0 calls/s, N =14, in M. minor ), and lacking clear harmonics (versus relatively clear harmonics at approximately 7.2 kHz in M. minor ); from M. rubrimera (data from Tapley et al. 2017a, recorded at 21.0–22.9 °C) by having the following, nonoverlapping call parameters, an average dominant frequency of 3.8 (3.6–4.7) kHz, N =60 (versus average 3.3 [3.2– 3.4] kHz, N =60, in M. rubrimera ), an average call duration of 41.9 (34–49) ms, N =60 (versus average 73.3 [62–85] ms, N= 60, in M. rubrimera ), an average call repetition rate of 3.9 (3.8–4.0) calls/s, N =60 (versus an average of 3.3 [3.1–3.3] calls/s, N= 60, in M. rubrimera ), and distinctly pulsed calls (versus indistinct pulsation in M. rubrimera ).

Figures

FIGURE 1. Distribution of Megophrys fansipanensis sp. nov. in the Hoang Lien Range, northern Vietnam.

FIGURE 3. Megophrys fansipanensis sp. nov. in preservative (holotype VNMN 2018.01). (A) Dorsal view, (B) ventral view. 10 mm scale bar.

FIGURE 4. Megophrys fansipanensis sp. nov. in preservative (holotype VNMN 2018.01). (A) Lateral view of head, (B) palmar surface of right hand, and (C) plantar surface of left foot. 5 mm scale bar.

FIGURE 5. Megophrys fansipanensis sp. nov. in life. (A) Dorsolateral view of holotype VNMN 2018.01, (B) dorsolateral view of paratype VNMN 07033, (C) lateral view of paratype VNMN 07033 showing groin colouration, (D) dorsal view of holotype VNMN 2018.01, (E) dorsal view of paratype VNMN 07033, (F) dorsal view of paratype AMS R186113, (G) dorsal view of paratype AMS R186108, (H) ventral view of paratype VNMN 07033, (I) ventral view of paratype AMS R186113, and (J) ventral view of paratype AMS R186108. Not to scale.

FIGURE 6. Megophrys fansipanensis sp. nov. in situ. (A) Unvouchered calling male, (B) type locality at 2242 m asl, Mount Fansipan, Sa Pa District, Lao Cai Province, Vietnam, (C) 2714 m asl, Mount Fansipan, Sa Pa District, Lao Cai Province, Vietnam, and (D) garbage and gravel quarrying at 2714 m asl, Mount Fansipan, Sa Pa District, Lao Cai Province, Vietnam.

FIGURE 7. Advertisement call of Megophrys fansipanensis sp. nov. paratype AMS R186114. (A) 60 s waveform of relative amplitude (Rel. amp.) over time for several call groups, (B) 10 s waveform of Rel. amp. over time for one call group, and (C) 1 s waveform and spectrogram of Rel. amp. and frequency for four calls. Recorded at an ambient air temperature of 15.3 °C.