Boulenophrys hungtai, Wang & Zeng & Lyu & Qi & Liu & Chen & Lu & Xiao & Lin & Chen & Wang, 2022

Wang, Jian, Zeng, Zhao-Chi, Lyu, Zhi-Tong, Qi, Shuo, Liu, Zu-Yao, Chen, Hong-Hui, Lu, Yu-Hong, Xiao, Hui-Wen, Lin, Can-Rong, Chen, Kai & Wang, Ying-Yong, 2022, Description of three new Boulenophrys species from eastern Guangdong, China, emphasizing the urgency of ecological conservation in this region (Anura, Megophryidae), Zootaxa 5099 (1), pp. 91-119 : 106-110

Boulenophrys hungtai sp. nov. Wang, Zeng, Lyu, Xiao & Wang

Hung-Ta Chang’s Horned Toad (in English) / Jiē Yáng Jiǎo Chán (DZffiDzdz in Chinese)

Figures 5–6

Holotype. SYS a007578, adult male, collected by Jian Wang, Hong-Hui Chen and Hui-Wen Xiao on 5 January 2019 from Mt. Liwangzhang (23°38'6.42"N, 115°48'51.78"E; ca. 990 m a.s.l.), Jiexi, Jieyang, Guangdong, China.

Paratypes (N=12). SYS a007575/ CIB118527 , SYS a007576–7577, 7579–7582, 7594–7597, adult males, collected on 5–6 January 2019 from the same stream as the holotype at elevations between 950–1000 m. SYS a008576, adult male, collected by Jian Wang, Hong-Hui Chen, and Shuo Qi on 28 February 2021 from Shuangkeng Forestry Station (23°43'56.25"N, 116°21'26.4"E; ca. 550 m a.s.l.), Jiedong, Jieyang, Guangdong, China .

Etymology. The specific epithet “ hungtai ” is a patronym in honor of Professor Hung-Ta Chang (=Hong-Da Zhang, 张Ȇffl, 1914–2016), an outstanding botanist who was born in Jiexi.

Diagnosis. (1) Small body size, SVL 25.8–33.3 mm (28.2 ± 2.3, N = 12) in adult males; (2) snout pointed in dorsal view; (3) tympanum moderate, TD/ED 0.52–0.61; (4) tympanic region smooth without granules or tubercles; (4) vomerine ridge and vomerine teeth absent; (5) margin of tongue rounded, not notched distally; (6) hindlimbs short, heels not meeting and tibio-tarsal articulation reaching forward to the region between tympanum and posterior corner of eye; (7) a subarticular tubercle present at the base of each fingers; (8) toes without lateral fringes and webbing; (9) distinct enlarged tubercles on the surface of limbs, flanks, chest, belly and around the cloaca; (10) tips of the tubercles on posterior abdomen, ventral thighs and around the cloaca bearing tiny spines; (11) single subgular vocal sac in males; (12) nuptial pads with villiform black nuptial spines on the dorsal surface of the first and second fingers in breeding males.

Comparisons. Comparative data of Boulenophrys hungtai sp. nov. and the other recognized members of Boulenophrys are listed in Table 3 .

Boulenophrys hungtai sp. nov. can be easily distinguished from Boulenophrys puningensis sp. nov. by having a moderately sized tympanum, TD/ED 0.52–0.61 (vs. tympanum large, TD/ED 0.68–0.71); lacking both a vomerine ridge and vomerine teeth (vs. vomerine ridge and vomerine teeth present); lacking webbing on toes (vs. having rudimentary webbing on toes).

Boulenophrys hungtai sp. nov. is strongly supported as the sister taxon to B. insularis , which is stated by Wang et al. (2017a) to be an endemic species of an offshore island in Shantou, China. Though the mean p -distance in the 16S gene is only 2.2 %, B. hungtai differs by having a snout pointed in dorsal view (vs. snout obtusely rounded in dorsal view); by the absence of vomerine ridge and vomerine teeth (vs. presence of strong vomerine ridge bearing vomerine teeth); margin of tongue not notched distally (vs. tongue notched distally); absence of webbing on toes (vs. having rudiment of webbing on toes); distinct enlarged tubercles on the surface of limbs, flanks, chest, belly and around the cloaca (vs. ventral surface smooth). Boulenophrys hungtai sp. nov. forms a clade with B. ombrophila (mean p -distance 4.9 % in the 16S gene), B. obesa (mean p -distance 3.9 % in the 16S gene), and B. cheni (mean p -distance 2.5 % in the 16S gene) though there is weak support for these relationships. However, the new species differs from the latter two congeners by having no webbing on toes (vs. having rudiment of webbing on toes in B. obesa ); no vomerine ridge (vs. presence of vomerine ridges in B. obesa ); a pointed snout in dorsal view (vs. snout rounded in dorsal view in B. ombrophila and B. obesa ); distinct enlarged tubercles on the surface of limbs, flanks, chest, belly and around the cloaca (vs. ventral surface smooth in B. ombrophila and B. obesa ); margin of tongue not notched distally, the shorter shanks with heels not meeting, absence of lateral fringes on toes (vs. tongue notched, heels meeting, presence of wide lateral fringes on toes in B. cheni ).

With a smaller body size, SVL 25.8–33.3 mm in adult males, Boulenophrys hungtai 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 in males), B. liboensis (60.5–67.7 mm in males), B. mirabilis (55.8–61.4 mm in males), B. omeimontis (56.0– 59.5 mm in males), B. sangzhiensis (54.7 mm in a single male), and B. shuichengensis (102.0– 118.3 mm in males).

In having relatively shorter shanks with heels that do not meet when the flexed hind limbs are held at right angles to the body axis, Boulenophrys hungtai sp. nov. can be easily distinguished from the following 31 congeners, i.e. B. angka , B. anlongensis , B. baishanzuensis , B. baolongensis , B. binchuanensis , B. binlingensis , B. boettgeri , B. congjiangensis , B. chishuiensis , B. jiangi , B. jinggangensis , B. jiulianensis , B. leishanensis , B. lini , B. minor , B. mufumontana , B. nanlingensis , B. palpebralespinosa , B. qianbeiensis , B. sanmingensis , B. shimentaina , B. shunhuangensis , B. spinata , B. tongboensis , B. wuliangshanensis , B. wushanensis , B. xiangnanensis , B. xianjuensis , B. yaoshanensis , B. yangmingensis , B. yingdeensis and B. yunkaiensis , all of which have relatively longer shanks with the heels meeting or overlapping.

By the absence of vomerine teeth, Boulenophrys hungtai sp. nov. differs from B. daiyunensis , B. daweimontis , B. dongguanensis , B. fansipanensis , B. frigida , B. hoanglienensis , B. nankunensis , and B. rubrimera , all of which have vomerine teeth.

By having a rounded margin of the tongue that is not notched distally, Boulenophrys hungtai sp. nov. differs from B. huangshanensis , B. kuatunensis , and B. lushuiensis , all of which have notched tongues. By the absence of lateral fringes on toes, Boulenophrys hungtai sp. nov. differs from B. acuta , and B. daoji , all of which have lateral fringes on toes. By the absence of webbing on toes, Boulenophrys hungtai sp. nov. differs from B. brachykolos , B. caobangensis , B. tuberogranulatus , and B. wugongensis , all of which have rudimentary webbing on toes. Boulenophrys hungtai sp. nov. further differs from the remaining B. lishuiensis by having raised tubercles bearing spines on their tips on surface of posterior abdomen (vs. surface of belly smooth in B. lishuiensis ).

Description of holotype. Adult male. Body size small, SVL 28.7 mm. Head width slightly larger than head length, HDW/HDL 1.11; snout pointed in dorsal view, projecting, sloping backward to mouth in profile, protruding well beyond margin of lower jaw; top of head flat; eyes moderate in size, ED 0.34 of HDL, pupil vertical, near diamond-shaped; nostril oblique-ovoid; canthus rostralis well developed; loreal region slightly oblique; internasal distance slightly larger than interorbital distance; tympanum moderate in size with an obvious margin, TD/ED 0.58; large ovoid choanae at base of maxilla; vomerine ridges and vomerine teeth absent, maxillary teeth present; margin of tongue rounded, not notched distally; presence of a single subgular vocal sac, and pair of slit-like openings at posterior of jaw.

Forearm (i.e., radioulna) length 0.22 of SVL and hand 0.23 of SVL; hand lacking webbing, fingers lacking lateral fringes, relative finger length I <II <IV <III; tips of fingers slightly dilated, round; subarticular tubercles absent; inner metacarpal tubercle greatly enlarged, outer metatarsal tubercle smaller; a single nuptial pad bearing nuptial spines present on dorsal surface of first and second fingers, respectively. Hind limbs short, tibio-tarsal articulation reaching forward to middle of tympanum when hind limb stretched along body; heels not meeting when flexed hind limbs held at right angles to body axis; crus (i.e., tibiofibular) length 0.39 of SVL and foot length 0.58 of SVL; relative toe length I <II <V <III <IV; tips of toes round and slightly dilated; toes without lateral fringes and with rudiment of webbing; inner metatarsal tubercle long ovoid, and lacking outer metatarsal tubercle.

Dorsal skin rough and granular, with fine tubercles; sparse large tubercles on flanks; single horn-like prominent tubercle on edge of upper eyelid; obvious supratympanic fold curving posteroventrally from posterior corner of eye to level above insertion of arm; tympanic region smooth without granules or tubercles; dense tubercles on skin of upper lip, upper eyelid, mandibular articulation, loreal, temporal region excluding tympanum and surface around cloaca; single discontinuous “X” shaped ridge on mid-dorsum; dense tubercles on shanks and thighs; ventral surface with dense raised tubercles; tubercles on surface of posterior abdomen, ventral surface of thighs and around cloaca bearing tiny spines at tip; small pectoral gland closer to axilla; single femoral gland positioned on posterior surface of thigh at midpoint between knee and cloaca.

Coloration of holotype in life. Dorsal surface of body maroon, with an incomplete dark brown triangular marking between eyes. Flanks yellowish brown. Two wide oblique black bands present on forearm. Dorsal surface of fingers and hindlimbs with dark grey transverse bands. Presence of vertical dark brown band below eye. Tip of tubercle on the edge of upper eyelid white. Supratympanic fold greyish white with orange mottling. Ventral surface of throat, chest, and sides of belly dark brown with white and orange mottling, black longitudinal band on surface of throat; central and posterior part of belly white, with dark brown patches and orange mottling. Tubercles on ventral surface of chest, belly, and thighs greyish white; spines on tips of tubercles on surface of posterior abdomen, ventral surface of thighs and around cloaca dark grey. Digits, inner and outer metacarpal tubercles, and inner metatarsal tubercle greyish white. Pectoral glands and femoral glands beige. Iris reddish brown.

Coloration of holotype in preservative. Maroon fades to dark brown dorsally. Coloration of flanks fades to greyish brown. Triangular marking between eyes and transverse bands on dorsal forearms and hind limbs become indistinct. Orange mottling on the supratympanic fold absent. Color of ventral surface fades; patterns of become indistinct; orange mottling on ventral skin absent. Pectoral glands and femoral glands greyish white.

Variation. Mensural data of the type series are listed in Table 5 . Most of the paratypes are similar to the holotype in morphology and color pattern, except for the following: coloration of dorsum is light brown and iris is reddish brown in the holotype (vs. dorsum beige and iris greyish white with irregular dark brown and light orange patterns in the paratype SYS a008576 ( Fig. 6A–B ); central and posterior part of belly white, with dark brown patches and orange mottling in the holotype (vs. ventral skin dark brown, without regular patches in the paratype SYS a008576 ( Fig. 6C–D ); larger body size in the paratypes SYS a007582 ( SVL 32.7 mm) and SYS 008576 ( SVL 33.3 mm); tibio-tarsal articulation reaching forward to middle of tympanum when hind limb stretched along body (vs. tibio-tarsal articulation reaching forward to posterior corner of eye in the paratypes SYS a007576, 7582, 7596, 7597, 8576).

Distribution and natural history. Currently, Boulenophrys hungtai sp. nov. is known from Mt. Liwangzhang of Jiexi (800–1000 m a.s.l.) and Shuangkeng Forestry Station (500–800 m a.s.l.) of Jiedong, which are ca. 55 km from each other. This toad inhabits flowing montane streams and the nearby forest floor and leaf litter, and is sympatric with Pachytriton brevipes ( Sauvage, 1876) . Cynops orphicus Risch, 1983 can also be observed in the surrounding area. Advertisement calls of males from Mt. Liwangzhang were heard from November to the following January. A single male (SYS a008576) from Shuangkeng Forestry Station was noticed discontinuously calling on March after the heavy rain. Males were found calling under the leaf litter or in rock crevices in flowing streams.

Figures

FIGURE 5. The holotype (SYS a007578) of Boulenophrys hungtai sp. nov. in life.

FIGURE 6. The paratype (SYS a008576) of Boulenophrys hungtai sp. nov. in life.

Tables

Table 5. Measurements (in mm) of the type series of Boulenophrys hungtai sp. nov., * indicates the holotype.

	SYS a007578*	SYS a007575	SYS a007576	SYS a007577	SYS a007579	SYS a007580	SYS a007581	SYS a007582	SYS a007594	SYS a007595	SYS a007596	SYS a007597	SYS a008576
Sex	Male	Male	Male	Male	Male	Male	Male	Male	Male	Male	Male	Male	Male
SVL	28.7	26.0	28.7	26.3	25.8	28.2	26.5	32.7	27.6	26.7	28.6	27.6	33.3
HDL	10.2	9.5	10.7	9.2	9.5	10.7	9.6	11.8	11.0	10.1	10.7	10.1	12.4
HDW	11.3	9.9	11.6	10.0	9.7	11.1	10.0	12.3	11.3	10.4	11.9	10.9	13.6
SNT	3.7	3.5	3.8	3.4	3.6	3.7	3.4	4.3	3.7	3.7	3.7	3.4	4.3
IND	3.4	3.5	3.6	3.3	3.5	3.6	3.3	4.2	3.8	3.5	3.5	3.5	4.3
IOD	3.3	3.4	3.4	3.2	3.2	3.5	3.0	3.8	3.6	3.2	3.4	3.5	4.0
ED	3.4	3.6	3.6	3.2	3.4	3.5	3.6	4.0	3.5	3.5	3.7	3.5	4.0
TD	2.0	1.9	2.1	1.9	2.0	2.0	2.0	2.3	2.1	2.1	2.1	1.8	2.4
TED	1.2	1.2	1.3	1.3	1.2	1.3	1.1	1.4	1.4	1.2	1.4	1.4	1.9
HND	6.6	6.7	7.0	6.6	6.3	6.4	6.5	8.6	6.8	6.5	7.0	6.6	8.7
RAD	6.2	5.7	6.7	5.6	5.3	6.2	5.9	7.7	6.2	6.0	6.6	5.7	7.9
TIB	11.1	11.2	12.0	10.8	10.1	11.4	10.6	13.6	11.7	10.7	12.3	11.1	13.9
FTL	16.8	14.9	17.2	15.2	15.0	15.7	15.5	19.7	16.3	15.4	17.7	16.2	20.6