Megophrys baishanzuensis, Wu & Li & Liu & Wang & Wu, 2020

Wu, Yanqing, Li, Shize, Liu, Wei, Wang, Bin & Wu, Jun, 2020, Description of a new horned toad of Megophrys Kuhl & Van Hasselt, 1822 (Amphibia, Megophryidae) from Zhejiang Province, China, ZooKeys 1005, pp. 73-102 : 73

Megophrys baishanzuensis sp. nov. Figs 4A, B, E, G, H , 5 , 6 , 7 , 8 ; Tables 1, 2, 3, 4, Suppl. materials 1,,, 4

Holotype.

CIBQY20200726001 (Figs 4A, B, E, G, H , 5 ), adult male, from Baishanzu National Park, Qingyuan County, Zhejiang Province, China (27.76°N, 119.18°E, ca. 1537 m a.s.l.), collected by Bin Wang on 26 July 2020.

Paratype.

Five adult males collected from the same place as holotype collected by Bin Wang. CIBQY20200719001-CIBQY20200719004 collected on 19 July 2020 by Bin Wang, and CIBQY20200726002 collected by Zhonghao Luo on 26 July 2020.

Other material examined.

One tadpole (CIBQY20200719005; Fig. 7 ) collected by Bin Wang on 19 July 2020.

Diagnosis.

Megophrys baishanzuensis sp. nov. is assigned to the genus Megophrys based on molecular phylogenetic analyses and the following generic diagnostic characters: snout shield-like; projecting beyond the lower jaw; canthus rostralis distinct; chest glands small and round, closer to the axilla than to midventral line; femoral glands on rear part of thigh; vertical pupils ( Fei et al. 2009).

Megophrys baishanzuensis sp. nov. could be distinguished from its congeners by a combination of the following morphological characters: body size small (SVL 28.4-32.4 mm in males); vomerine teeth absent; tongue not notched behind; tympanum distinctly visible, oval; a small horn-like tubercle at the edge of each upper eyelid; two metacarpal tubercles distinctly visible in hand; toes without webbing; heels overlapping when thighs are positioned at right angles to the body; tibiotarsal articulation reaching the level to the middle of eye when leg stretched forward.

Description of holotype.

(Figs 4A, B, E, G, H , 5 ). SVL 28.5 mm; head width larger than head length (HDW/HDL ratio ca. 1.3); snout obtusely pointed, protruding well beyond the margin of the lower jaw in ventral view; loreal region vertical and concave; canthus rostralis well-developed; top of head flat in dorsal view; eye large, eye diameter 46.0% of head length; pupils vertical; nostril orientated laterally, closer to snout than eye; tympanum distinct, 55.8% of eye diameter; vomerine ridges present and vomerine teeth absent; margin of tongue smooth, not notched behind.

Forelimbs slender, the length of lower arm and hand 47.0% of SVL; fingers slender, relative finger lengths: I <II <IV <III; tips of digits globular, without lateral fringes; subarticular tubercle distinct at the base of each finger; two metacarpal tubercles, prominent, oval-shaped, the inner one bigger than the outer one.

Hindlimbs slender, tibia length 46.5% times of SVL; heels overlapping when thighs are positioned at right angles to the body, tibiotarsal articulation reaching the middle of eye when leg stretched forward; tibia length longer than thigh length; relative toe lengths I <II <V <III <IV; tips of toes round, slightly dilated; subarticular tubercles absent on each toes; toes without webbing but with narrow lateral fringe; inner metatarsal tubercle oval-shaped; outer metatarsal tubercle absent.

Dorsal skin rough, several large warts scattered on flanks; a small horn-like tubercle at the edge of each upper eyelid; tubercles on the dorsum forming a X-shaped ridge, two dorsolateral parallel ridges on either side of the X-shaped ridges; an inverted triangular brown speckle between two upper eyelidsseveral tubercles scattered on dorsal, flanks and dorsal surface of thighs and tibias; supratympanic fold distinct.

Numerous granules scattered on ventrum; pectoral and femoral glands distinct; numerous white granules on outer thighs.

Coloration of holotype in life. (Fig. 5 ). Dorsal brown, several pink tubercles scattered on dorsal, an inverted triangular brown speckle between the eyes; X-shaped ridges on the dorsum brown, four dark transverse bands on the dorsal surface of the thigh and shank; ventral surface of body white with brown spots; two dark brown dark bars on the flanks, throat brown; white vertical bars on lower and upper lip; ventral surface of anterior limb dark reddish purple, posterior limb orange with numerous white granules; tip of digits pale grey; inner metatarsal tubercle and two metacarpal tubercles pinkish; soles uniform dark reddish purple; pectoral glands white.

Coloration of holotype in preservation. (Fig. 4A, B, E, G, H ). Color of dorsal surface fades to taupe; the inverted triangular brown speckle between the eyes and brown X-shaped ridges on dorsum are more distinct; ventral surface greyish white; creamy-white substitutes the purple grey on tip of digits; the posterior of ventral surface of body, inner of thigh and upper of tibia fades to creamy-white.

Variation. Fig. 6 . Measurements and basic statistics of adult specimens are presented in Tables 3 and Supp. material 1. All specimens were similar in morphology but some individuals different from the holotype in color pattern. In CIBQY2020200719001 the tubercles on the dorsum forming two ≻ shaped, disconnected ridges (Fig. 6A ); in CIBQY2020200719004 the tubercles on the dorsum forming a big and distinct X-shaped speckle (Fig. 6B ); in CIBQY2020200719003 ventral surface of body grey with brown spots (Fig. 6C ); in CIBQY2020200726002 ventral surface of body and limbs brownish red (Fig. 6D ).

Tadpole description. Fig. 7 . The tadpole CIBQY20200719006 (Fig. 7 ) was confirmed as Megophrys baishanzuensis sp. nov by molecular phylogenetic analyses. Measurements in mm. Stage 31. Body slender, body brownish black and tail pale brown, body height greater than tail height; dorsal fin arising behind the origin of the tail, the highest fin near mid-length, tapering gradually to the narrowly pointed tip; tail approximately 1.9 times as long as snout-vent length; tail height 13.6% of tail length; body width longer than body height (BW/BH1.2); eyes large, lateral, nostril near eyes; spiracle on the left side of the body and distinct; oral disk terminal, lips expanded and directed upwardly into a umbelliform oral disk; flank of body brownish black with some white spots, tail fins lightly colored, with small white and black spots. TOL 22.7; SVL 8.7; BW 3.0; BH 2.7; SL 2.0; SS 4.0; IOS 1.8; TAL 14.7; TAH 2.2; TBD 1.5; MW 1.3.

Advertisement call. Fig. 4 . The call description is based on recordings of the holotype CIBQY20200726001 (Fig. 4 ; Table 4 ) from a shrub leaf near the streamlet. Call duration was 151.0-170.0 ms (mean 162.4 ± 5.7). Inter-call interval was 682.0-1869.0 ms (mean 936.8 ± 349.0). Pulse/call was 23.0-30.0 (mean 26.0 ± 2.4); pulse duration was 3.0-6.0 (mean 4.9 ± 6.0) and call repetition rate was 0.79 call/s.

Amplitude modulation within note was apparent, beginning with moderately high energy pulses, increasing to the maximum by approximately quarter, and then decreasing towards the end. The average dominant frequency was 3.36 ± 0.06 (3.19-3.38 kHz).

Secondary sexual characters. A single subgular vocal sac present in male. In breeding season, nuptial pads are present on the dorsal base of the first two fingers in males.

Comparisons.

Supp. material 4. By having small body size, Megophrys baishanzuensis sp. nov. differs from M. ancrae , M. auralensis , M. awuh , M. baluensis , M. baolongensis , M. binlingensis , M. boettgeri , M. caobangensis , M. carinense , M. caudoprocta , M. chishuiensis , M. chuannanensis , M. damrei , M. daweimontis , M. dzukou , M. edwardinae , M. feae , M. flavipunctata , M. gigantica , M. glandulosa , M. hansi , M. himalayana , M. hoanglienensis , M. huangshanensis , M. insularis , M. jiangi , M. jingdongensis , M. jinggangensis , M. kalimantanensis , M. kobayashii , M. lancip , M. lekaguli , M. liboensis , M. ligayae , M. lini , M. longipes , M. major , M. mangshanensis , M. medogensis , M. megacephala , M. mirabilis , M. montana , M. monticola , M. nasuta , M. obesa , M. omeimontis , M. orientalis , M. pachyproctus , M. palpebralespinosa , M. parallela , M. parva , M. periosa , M. platyparietus , M. popei , M. sangzhiensis , M. serchhipii , M. shapingensis , M. shuichengensis , M. spinata , M. takensis M. wawuensis , and M. xiangnanensis (maximum SVL <33.0 mm in the new species vs. minimum SVL> 34.0 mm in the latter).

By vomerine teeth absent, Megophrys baishanzuensis sp. nov. differs from M. ancrae , M. baluensis , M. carinense , M. caudoprocta , M. chuannanensis , M. damrei , M. daweimontis , M. dongguanensis , M. dzukou , M. fansipanensis , M. feae , M. flavipunctata , M. glandulosa , M. himalayana , M. hoanglienensis , M. insularis , M. intermedia , M. jingdongensis , M. jinggangensis , M. jiulianensis , M. kalimantanensis , M. kobayashii , M. lancip , M. lekaguli , M. liboensis , M. ligayae , M. longipes , M. mangshanensis , M. maosonensis , M. medogensis , M. megacephala , M. montana , M. nankunensis , M. nanlingensis , M. nasuta , M. numhbumaeng , M. omeimontis , M. oreocrypta , M. orientalis , M. oropedion , M. pachyproctus , M. palpebralespinosa , M. parallela , M. parva , M. periosa , M. platyparietus , M. popei , M. robusta , M. rubrimera , M. serchhipii , M. Megophrys shimentaina , M. stejnegeri , M. takensis , M. zhangi , and M. zunhebotoensis (vs. present in the latter).

By a small horn-like tubercle present at the edge of each upper eyelid, Megophrys baishanzuensis sp. nov. differs from M. aceras , M. acuta , M. carinense , M. caudoprocta , M. chuannanensis , M. feae , M. gerti , M. hansi , M. intermedia , M. intermedia , M. jinggangensis , M. kalimantanensis , M. koui , M. lancip , M. liboensis , M. microstoma , M. montana , M. nasuta , M. orientalis , M. palpebralespinosa , M. platyparietus , M. popei , M. shuichengensis , M. stejnegeri , and M. synoria (vs. having a prominent and elongated tubercle in the latter).

By tongue not notched behind, Megophrys baishanzuensis sp. nov. differs from M. ancrae , M. baolongensis , M. binlingensis , M. boettgeri , M. carinense , M. cheni , M. chuannanensis , M. damrei , M. dringi , M. dzukou , M. fansipanensis , M. feae , M. feii , M. flavipunctata , M. gerti , M. glandulosa , M. hoanglienensis , M. huangshanensis , M. insularis , M. jiulianensis . M. jingdongensis , M. kalimantanensis , M. kuatunensis , M. liboensis , M. mangshanensis , M. maosonensis , M. medogensis , M. minor , M. nankiangensis , M. nanlingensis , M. numhbumaeng , M. omeimontis , M. oropedion , M. pachyproctus , M. parallela , M. popei , M. robusta , M. sangzhiensis , M. shapingensis , M. shuichengensis , M. spinata , M. vegrandis , M. wawuensis , M. zhangi , and M. zunhebotoensis (vs. notched behind in the latter).

By toes with narrow lateral fringes, Megophrys baishanzuensis sp. nov. differs from M. angka , M. baolongensis , M. brachykolos , M. caobangensis , M. chishuiensis , M. damrei , M. daweimontis , M. dongguanensis , M. fansipanensis , M. feae , M. himalayana , M. hoanglienensis , M. huangshanensis , M. insularis , M. jiangi , M. jiulianensis , M. kalimantanensis , M. koui , M. leishanensis , M. lekaguli , M. lishuiensis , M. major , M. mangshanensis , M. medogensis , M. megacephala , M. microstoma , M. minor , M. nankunensis , M. obesa , M. ombrophila , M. oreocrypta , M. oropedion , M. pachyproctus , M. parva , M. periosa , M. shunhuangensis , M. takensis , M. tuberogranulata , M. wawuensis , M. wugongensis , M. wuliangshanensis and M. xianjuensis (vs. lacking in the latter); and differs from M. binchuanensis , M. boettgeri , M. carinense , M. cheni , M. chuannanensis , M. dringi , M. feii , M. gigantica , M. glandulosa , M. intermedia , M. jingdongensis , M. liboensis , M. lini , M. orientalis , M. palpebralespinosa , M. platyparietus , M. shapingensis , M. shuichengensis , M. Megophrys spinata , and M. xiangnanensis (vs. with wide lateral fringes in the latter).

By toes without webbing, Megophrys baishanzuensis sp. nov. differs from M. brachykolos , M. carinense , M. flavipunctata , M. jingdongensis , M. jinggangensis , M. lini , M. major , M. palpebralespinosa , M. popei , M. shuichengensis , and M. spinata (vs. at least one-fourth webbed in the latter).

By heels overlapping when thighs are positioned at right angles to the body, Megophrys baishanzuensis sp. nov. differs from M. actuta , M. brachykolos , M. dongguanensis , M. huangshanensis , M. kuatunensis , M. nankunensis , M. obesa , M. ombrophila , M. wushanensis , and M. wugongensis (vs. just meeting or not meeting in the latter).

By tibiotarsal articulation reaching to the level to the middle of eye when leg stretched forward, Megophrys baishanzuensis sp. nov. differs from M. daweimontis , M. glandulosa , M. lini , M. major , M. medogensis , M. obesa , M. sangzhiensis , and M. yangmingensis (vs. reaching the anterior corner of the eye or beyond eye or nostril and tip of snout in the latter); differs from M. mufumontana (vs. reaching tympanum in males and to the eye in females in the latter); and differs from M. chishuiensis (vs. reaching the level between tympanum and eye in the latter).

By having an internal single subgular vocal sac in male, Megophrys baishanzuensis sp. nov. differs from M. caudoprocta , M. shapingensis , and M. shuichengensis (vs. vocal sac absent in the latter).

The congeners M. boettgeri , M. lishuiensis , M. ombrophila , and M. xianjuensis all occur in Wuyi Mountains, Fujian Province and/or Zhejiang Province, China, and probably have sympatric distribution with Megophrys baishanzuensis sp. nov. ( Fei et al. 2012; Wang et al. 2017b; Messenger et al. 2019; Wang et al. 2020). The new species can be distinguished from these species by a series of morphological characters as follows. The new species differs from M. boettgeri by body size smaller (adult males with 28.4-32.4 mm vs. adult males with 34.5-37.8 mm), and in breeding male nuptial pads present on the dorsal base of the first two fingers (vs. nuptial pad only on the first finger). The new species differs from M. lishuiensis by vomerine ridges present (vs. absent), toes with narrow lateral fringe (vs. without), and tibiotarsal articulation reaching the middle of eye when leg stretched forward (vs. reaching the range from tympanum to eye). The new species differs from M. ombrophila by heels overlapping when thighs are positioned at right angles to the body (vs. not meeting), vomerine ridges present (vs. absent), and toes with narrow lateral fringe (vs. without). The new species differs from M. xianjuensis by tibiotarsal articulation reaching the middle of eye when leg stretched forward (vs. reaching the range from tympanum to eye), and toes with narrow lateral fringe (vs. without).

Megophrys baishanzuensis sp. nov. is phylogenetically closest to M. kuatunensis . Megophrys baishanzuensis sp. nov. could be identified from M. kuatunensis distinctly by tibiotarsal articulation reaching the middle of eye when leg stretched forward (vs. reaching the range from tympanum to eye), heels overlapping when thighs are positioned at right angles to the body (vs. not meeting), tongue not notched behind (vs. notched feebly), the supratympanic fold more expanded in dorsal view and tympanum protruding (vs. concave), and having significantly lower ratios of UEW and TFL to SVL in males (all p -values <0.05; Table 3 ). On call characters, the new species has slower call repetition rate (0.79 call/s in the new species vs. 1.18 call/s in M. kuatunensis ), and has lower dominant frequency (3.19-3.38 kHz in the new species vs. 3.38-3.75 kHz in M. kuatunensis ).

Distribution and habitat.

Megophrys baishanzuensis sp. nov. is known from the type locality, Baishanzu National Park, Qingyuan County Zhejiang Province, China, at elevations between 1400-1600 m. The individuals of the new species were frequently found in the stream surrounded by evergreen broadleaved forests (Fig. 9 ). M. boettgeri was also found in the same stream.

Etymology.

The specific name Megophrys baishanzuensis refers to the distribution of this species, Baishanzu National Park, Qingyuan County, Zhejiang Province, China. We propose the common name "Baishanzu horned toad" (English) and Bai Shan Zu Jiao Chan (百山祖角蟾, Chinese).

Figures

Figure 4. Visualization of advertisement calls of Megophrys baishanzuensis sp. nov. and M. kuatunensis A-C waveform showing 10 seconds, waveform showing 0.2 seconds and sonogram showing 0.2 seconds of CIBQY 20200726001 of Megophrys baishanzuensis sp. nov. D-F waveform showing 10 seconds, waveform showing 0.2 seconds and sonogram showing 0.2 seconds of CIBWY 18082410 of M. kuatunensis.

Figure 5. Photos of the holotype specimen CIBQY 20200726001 of Megophrys baishanzuensis sp. nov. and topotype specimen of M. kuatunensis A, B, E, G, H dorsal view of body, ventral view of body, lateral view of head, ventral view of hand, and ventral view of foot of CIBQY 20200726001, respectively C, D, F, I, J dorsal view of body, ventral view of body, lateral view of head, ventral view of hand, and ventral view of foot of CIBWY 18082413, respectively. Red arrow points to tympanum.

Figure 6. Photos of the holotype CIBQY 20200726001 of Megophrys baishanzuensis sp. nov. in life A dorsal view B ventral view C lateral view D ventral view of hand E ventral view of foot.

Figure 7. Color variation in Megophrys baishanzuensis sp. nov. in life A dorsal view of the adult male CIBQY 2020200719001 B dorsal view of the adult male CIBQY 2020200719004 C ventral view of the adult male CIBQY 2020200719003 D ventral view of the adult male CIBQY 2020200726002.

Figure 8. Photos of the tadpole CIBQY 20200719006 of Megophrys baishanzuensis sp. nov. in life A dorsal view B lateral view.

Figure 9. Habitats of Megophrys baishanzuensis sp. nov. in the type locality, Baishanzu Naitonal Park, Qingyuan County, Zhejiang Province, China A landscape for forest B the stream under the forest inhabited by Megophrys baishanzuensis sp. nov.