Boulenophrys yaoshanensis, Qi & Lyu & Wang & Mo & Zeng & Zeng & Dai & Li & Grismer & Wang, 2021

Qi, Shuo, Lyu, Zhi-Tong, Wang, Jian, Mo, Yun-Ming, Zeng, Zhao-Chi, Zeng, Yang-Jin, Dai, Ke-Yuan, Li, Yuan-Qiu, Grismer, L. Lee & Wang, Ying-Yong, 2021, Three new species of the genus Boulenophrys (Anura, Megophryidae) from southern China, Zootaxa 5072 (5), pp. 401-438 : 412-416

Boulenophrys yaoshanensis sp. nov. Qi, Mo, Lyu, Wang & Wang

Mt. Dayao Horned Toad / yao shan jiao chan (Ṉ山fflDz)

Figures 3 , 7A

Chresonymy. Megophrys minor — Liu & Hu 1962

Megophrys brachykolos — Fei et al. 2009; Mo et al. 2014

Boulenophrys brachykolos — Fei & Ye 2016; Fei 2020

Megophrys sp 31 (SYS a002189–2190, 4850–4851, 4878)— Liu et al. 2018

Holotype. SYS a002189 ( Figures 3A , 7A ), adult male, collected on 8 July 2013 by Yu-Long Li and Ying-Yong Wang from the Dayaoshan Nature Reserve (26.5517°N, 114.1548°E; ca 845 m a.s.l.), Jinxiu Yao Autonomous County, Guangxi Zhuang Autonomous Region, China.

Paratypes. Five adult specimens from the same locality as the holotype: male SYS a000838 collected on 13 September 2011 by Yu-Long Li and Ying-Yong Wang ; males SYS a004850 and SYS a004851 / CIB 116086 collected on 1 June 2016 by Jian Wang ; female SYS a004878 ( Figure 3B ) collected on 3 June 2016 by Jian Wang ; male SYS a007023 collected on 1 June 2019 by Zhi-Tong Lyu and Yu-Long Li . Female NHMG1503016 collected on 18 March 2015 by Yun-Ming Mo from the Mt. Xianglu (24.1055°N, 110.2300°E; ca 1305 m a.s.l.), Jinxiu Yao Autonomous County ; male NHMG201705032 collected on 5 May 2017 by Yun-Ming Mo from 16 km west of Jinxiu Yao Autonomous County (24.1162°N, 110.2491 °E, ca 1115m a.s.l.), Guangxi Zhuang Autonomous Region, China .

Etymology. The specific epithet yaoshanensis refers to the type locality, the Dayaoshan Nature Reserve, Guangxi, China. Particularly, we employ the epithet “yaoshan” rather than “dayaoshan” to make it consistent with other zoological and botanical species discovered from this area, e.g. Zhangixalus yaoshanensis ( Liu & Hu, 1962) , Leptobrachium liui yaoshanensis ( Liu & Hu, 1978) , Litsea yaoshanensis Yang & Huang, 1978 , and Rhododendron yaoshanicum Fang & He, 1983 ( Liu & Hu, 1962; Liu et al. 1978; Yang et al. 1978; Fang & He, 1983).

Diagnosis. (1) Small body size, SVL 32.5–42.6 mm (37.1 ± 3.5, N = 6) in adult males and SVL 46.6–47.4 mm (47.0 ± 0.6, N = 2 in adult females; (2) snout rounded in dorsal view; (3) tympanum boundary clear, ED/TD 1.38–1.85 in males, 1.50–1.77 in females; (4) weak vomerine ridge present, vomerine teeth absent; (5) margin of tongue rounded, not notched posteriorly; (6) hind limbs slender, heels slightly overlapping or meeting, and tibiotarsal articulation reaching eye when leg stretched forward; (7) tibia 0.45–0.51 of SVL and foot 0.63–0.73 of SVL in males, tibia 0.44–0.47 of SVL and foot 0.63–0.67 of SVL in females; (8) toes without lateral fringes and with rudimentary webbing; (9) small horn-like tubercle at the edge of upper eyelid present; (10) skin of dorsum relatively smooth, a discontinuous “X”-shaped ridge on at mid-dorsum; (11) a few sparsely distributed large tubercles on flanks; (12) body yellowish brown dorsally, an inverted hollow dark-brown triangularly shaped marking between eyes, a dark “X”-shaped making at mid-dorsum; (13) single subgular vocal sac in males; (14) presence of villiform black nuptial spines on dorsal surface of first and second fingers in adult males.

Comparisons. Comparative data of Boulenophrys yaoshanensis sp. nov. to other recognized members of the genus Boulenophrys are listed in Table 3 .

Having a smaller body size with SVL 32.5–42.6 mm in males, Boulenophrys yaoshanensis sp. nov. differs from the seven congeners whose SVL> 50 mm in males, including B. caudoprocta (81.3 mm in a single male), B. jingdongensis (53.0– 56.5 mm), B. liboensis (60.5–67.7 mm), B. mirabilis (55.8–61.4 mm), B. omeimontis (56.0– 59.5 mm), B. sangzhiensis (54.7 mm in a single male), and B. shuichengensis (102.0– 118.3 mm).

Having relatively longer shanks with heels that overlap or meet when the flexed hind limbs are held at right angles to the body axis, Boulenophrys yaoshanensis sp. nov. can be easily distinguished from the following nine congeners, B. acuta , B. brachykolos , B. daoji , B. dongguanensis , B. insularis , B. nankunensis , B. obesa , B. ombrophila , and B. wugongensis (vs. all of which have relatively shorter shanks with the heels not meeting).

Lacking vomerine teeth, Boulenophrys yaoshanensis sp. nov. differs from B. caudoprocta , B. daiyunensis , B. daweimontis , B. dongguanensis , B. fansipanensis , B. frigida , B. hoanglienensis , B. insularis , B. jingdongensis , B. jinggangensis , B. jiulianensis , B. liboensis , B. nankunensis , B. nanlingensis , B. omeimontis , B. palpebralespinosa , B. qianbeiensis , B. rubrimera , B. sangzhiensis , B. shimentaina , and B. tongboensis (vs. presence of vomerine teeth in these species).

Having an unnotched tongue, Boulenophrys yaoshanensis sp. nov. can be distinguished from B. baolongensis , B. binlingensis , B. boettgeri , B. cheni , B. hoanglienensis , B. huangshanensis , B. insularis , B. jingdongensis , B. jiulianensis , B. kuatunensis , B. liboensis , B. lushuiensis , B. minor , B. nanlingensis , B. ombrophila , B. qianbeiensis , B. sangzhiensis , B. sanmingensis , B. shuichengensis B. spinata , and B. tongboensis (vs. tongue notched posteriorly in these species).

Lacking lateral fringes on toes, Boulenophrys yaoshanensis sp. nov. differs from B. acuta , B. anlongensis , B. baishanzuensis , B. binchuanensis , B. boettgeri , B. congjiangensis , B. cheni , B. daiyunensis , B. daoji , B. jingdongensis , B. jinggangensis , B. liboensis , B. lini , B. lushuiensis , B. mirabilis , B. mufumontana , B. nanlingensis , B. omeimontis , B. palpebralespinosa , B. qianbeiensis , B. rubrimera , B. sangzhiensis , B. sanmingensis , B. shimentaina , B. shuichengensis , B. spinata , B. xiangnanensis , B. xianjuensis , and B. yangmingensis (vs. presence of lateral fringes on toes in these species); and from B. wushanensis (vs. presence of wide lateral fringes on toes in males while lacking in females).

Having rudimentary webbing on toes, Boulenophrys yaoshanensis sp. nov. differs from B. baishanzuensis , B. baolongensis , B. daweimontis , B. fansipanensis , B. frigida , B. huangshanensis , B. kuatunensis , B. lishuiensis , B. ombrophila , B. rubrimera , B. tongboensis , and B. wuliangshanensis (vs. absence of webbing on toes in these species); and from B. jingdongensis , B. palpebralespinosa , B. qianbeiensis , B. shuichengensis , and B. spinata (vs. presence of well-developed webbing on toes in these species).

For the remaining seven species, Boulenophrys yaoshanensis sp. nov. can be further distinguished by the body size with SVL 46.6–47.4 mm in females (vs. 37.5–39.2 mm in B. angka , 39.5–40.4 mm in B. jiangi , 42.3 mm in B. leishanensis , 37.6 mm in B. shunhuangensis , and 50.5 mm in B. tuberogranulatus ), the relative finger lengths II <I <IV <III (vs. I <II <IV <III in B. angka, IV <I <II <III in B. caobangensis ), tibio-tarsal articulation reaching eye when leg stretched forward (vs. between the nasal and tip of snout in B. shunhuangensis ; between tympanum and eye in B. chishuiensis ), dorsal skin relatively smooth (vs. dorsal skin rough with numerous granules in B. chishuiensis and B. tuberogranulatus ), and absence of any spines on head (vs. presence of small black spines on temporal region in B. caobangensis ).

Description of holotype. Adult male. small body size, SVL 37.3 mm; head length equal to head width, HDW/ HDL 1.00; snout rounded in dorsal view, projecting well beyond the margin of lower jaw, sloping backward to mouth lateral in profile; top of head flat; eyes moderate in size, ED 0.38 of HDL, pupil vertical, near diamondshaped; nostril oblique-ovoid; canthus rostralis well developed; loreal region slightly oblique; internasal distance slightly larger than interorbital distance; tympanum clear, ED/TD 1.68; large ovoid choanae at the base of the maxilla; weak vomerine ridge present, vomerine teeth absent, maxillary teeth present; margin of tongue rounded, not notched posteriorly; a single subgular vocal sac present, and a pair of slit-like openings at posterior of jaw.

Radio-ulnar length 0.23 of SVL and hand 0.27 of SVL; hand without webbing, fingers without lateral fringes, relative finger length II <I <IV <III; tips of fingers slightly dilated, round; subarticular tubercles absent; inner metacarpal tubercle greatly enlarged and the outer metatarsal tubercle smaller; a single nuptial pad on the dorsal surface of the first and second fingers. Hind limbs slender, tibio-tarsal articulation reaching beyond the posterior margin of eye when hind limb stretched alongside the body; heels just meeting when flexed hind limbs held at right angles to body axis; tibia length 0.47 of SVL and foot length 0.64 of SVL; relative toe length I <II <V <III <IV; tips of toes round, slightly dilated; toes without lateral fringes and with rudimentary webbing; inner metatarsal tubercle long ovoid and outer metatarsal tubercle absent.

Skin of dorsum relatively smooth with small granules; sparsely distributed large tubercles on flanks; a small, horn-like prominent tubercle on the edge of upper eyelid; unpigmented supratympanic fold curving posteroventrally from posterior margin of eye to a level above insertion of arm; a discontinuous “X”-shaped ridge at mid-dorsum; a few sparsely distributed large tubercles on flanks; sparsely distributed tubercles on dorsal surface of foreleg and thigh; ventral surfaces smooth; area around cloaca bearing small, spinose tubercles males; small pectoral gland close to axillae; and a single femoral gland on positioned subequally distant from knees and cloaca on posterior surface of each thigh..

Coloration of holotype in life. Dorsal surface of body yellowish brown with an inverted hollow dark-brown triangularly shaped marking between eyes; an “X” shaped marking on the mid-dorsum. Forearms and hind limbs with dark-brown transverse bands. Supratympanic fold light-colored; a dark vertical band below the eye, from the inferior margin of the eye to the upper lip. Ventral surface of throat and chest greyish brown with dark-brown patches; ventral surface of body greyish white with creamy white and orange spots, ventral surface of limbs greyish brown with dark brown spots; ventral surfaces of hands and feet brown, tips of digits pale brown; metacarpal tubercle and metatarsal tubercle reddish. Pectoral gland and femoral gland white. Iris yellowish brown.

Coloration of holotype in preservative. Yellowish brown faded to greyish brown dorsally. Triangular marking between eyes, “X” shaped marking on the mid-dorsum, transverse bands on dorsal forearms and hind limbs became indistinct. Color of ventral surface faded to greyish white, all bands and spots became indistinct.

Variation and sexual dimorphism. Mensural data of the type series are listed in Table 4 . Two females ( SYS a004878, SVL 46.6 mm; NHMG1503016 , SVL 47.4 mm) are distinctly larger than the males ( SVL 32.5–42.6 mm). Three paratypes ( SYS a004850–4851, 4878) have subarticular tubercles on the first phalangeal articulations of the fingers. The holotype and two male paratypes ( SYS a004850–4851) have small, spinose tubercles around the cloaca. Villiform black nuptial spines occur on the dorsal surface of the first and second fingers in adult males .

Distribution and ecology. Currently, Boulenophrys yaoshanensis sp. nov. is known only from Jinxiu and Mengshan counties, Guangxi, China. All individuals were found in evergreen secondary forest, inhabiting flowing montane streams and the nearby forest floor and leaf litter at elevations between 800–1350 m. Males call while perched on leaves from May to July, suggesting their breeding season corresponds to this period. Females were found on the forest floor and tadpoles were not observed.

Figures

FIGURE 3. Boulenophrys yaoshanensis sp. nov. in life. A: holotype (SYS a002189), male; B: paratype (SYS a004878), female; 1: dorsolateral view; 2: ventral view; 3: hand; 4: foot.

FIGURE 7. Comparisons of lateral position of the head with three new Boulenophrys species in preservative. The white arrows marking tubercles bearing tiny spine in Boulenophrys yunkaiensis sp. nov.. A: Boulenophrys yaoshanensis sp. nov. (SYS a002189); B: Boulenophrys yingdeensis sp. nov. (SYS a002099); C: Boulenophrys yunkaiensis sp. nov. (SYS a004637).