Megophrys (Panophrys) dongguanensis J. Wang & Y.Y. Wang

Wang, Jian, Lyu, Zhi-Tong, Liu, Zu-Yao, Liao, Cheng-Kai, Zeng, Zhao-Chi, Zhao, Jian, Li, Yu-Long & Wang, Ying-Yong, 2019, Description of six new species of the subgenus Panophrys within the genus Megophrys (Anura, Megophryidae) from southeastern China based on molecular and morphological data, ZooKeys 851, pp. 113-164 : 120-123

Megophrys (Panophrys) dongguanensis J. Wang & Y.Y. Wang sp. nov. Fig. 3, Table 4

Holotype.

SYS a001973, adult male, collected by Run-Lin Li on 13 December 2012 from Mt. Yinping, Xiegang County (22°54'17.20"N, 114°13'23.88"E; 132 m a.s.l.), Dongguan City, Guangdong Province, China.

Paratypes (10 males).

SYS a002007, adult male, collected on 17 March 2013 by Run-Lin Li from Mt. Yinping, Qingxi County (22°53'26.21"N, 114°10'14.82"E; 277 m a.s.l.), Dongguan City, China; adult males, SYS a001971/CIB110006, SYS a001972, 1974-1975, collected on 12-13 December 2012, SYS a001492-1495, collected on 23 December 2012 by Run-Lin Li from the same locality as the holotype (100-300 m a.s.l.).

Diagnosis.

(1) Body size small to moderate, SVL 30.2-39.3 mm in 11 adult male specimens; (2) head width slightly larger than head length, HDW/HDL ratio 1.04-1.09; (3) snout pointed in dorsal view; (4) tympanum distinct, moderate-sized, TD/ED ratio 0.42-0.60; (5) strong vomerine ridge bearing vomerine teeth; (6) margin of tongue not notched behind; (7) hindlimbs short, heels not meeting, tibio-tarsal articulation reaching the region between tympanum and eye; (8) presence of subarticular tubercles and absence of lateral fringes on fingers, relative finger lengths II <I ≤ IV <III; (9) toes with rudiment of webbing at their bases and without lateral fringes, subarticular tubercles only present at the base of each toe; (10) numerous granules present on dorsal surface of body, several large tubercles present on surface of flanks; (11) presence of a barely visible reddish horn-like tubercle at the edge of the upper eyelid; (12) supratympanic fold distinct, whitish; (13) yellowish brown dorsally, with an incomplete dark triangular marking between eyes and usually an X-shaped marking on back of trunk; (14) ventral surface black brown, with white spots on posterior surface of abandon; (15) males with a single subgular vocal sac; (16) presence of nuptial pads with darker nuptial spines on dorsal surface of the first and second fingers in adult males during breeding season, respectively.

Comparisons.

Comparative data of Megophrys dongguanensis sp. nov. with M. feii and the 33 recognized members of Megophrys s.l. allocated to the subgenus Panophrys are listed in Table 5.

With significantly smaller body size, SVL 30.2-39.3 mm in males, Megophrys dongguanensis sp. nov. differs from the eight members with larger SVL values: M. baolongensis (42.0-45.0 mm in males), M. binlingensis (45.1-51.0 mm in males), M. caudoprocta (81.3 mm in male), M. jingdongensis (53.0-56.5 mm in males), M. omeimontis (56.0-59.5 mm in males), M. sangzhiensis (54.7 mm in single male), M. spinata (47.2-54.4 mm in males) and M. shuichengensis (102.0-118.3 mm in males).

Megophrys dongguanensis sp. nov. differs from 12 species occurring in eastern and southern China ( M. acuta , M. brachykolos , M. boettgeri , M. cheni , M. huangshanensis , M. insularis , M. jinggangensis , M. kuatunensis , M. lini , M. lishuiensis , M. obesa and M. ombrophila ) by the following combination of characters: presence of vomerine teeth (vs. absent in M. acuta , M. boettgeri , M. brachykolos , M. cheni , M. huangshanensis , M. kuatunensis , M. lini , M. lishuiensis , M. obesa and M. ombrophila ), margin of tongue not notched posteriorly (vs. notched in M. boettgeri , M. cheni , M. huangshanensis , M. insularis and M. kuatunensis ), absence of lateral fringes on toes (vs. presence of narrow lateral fringes on toes in M. acuta , M. jinggangensis and M. kuatunensis ; presence of wide lateral fringes on toes in M. boettgeri , M. cheni and M. lini ), toes with rudimentary webbing (vs. toes without webbing in M. lishuiensis , M. kuatunensis and M. ombrophila ), hindlimbs short, with heels not meeting when the flexed hindlimbs are held at right angles to the body axis (vs. hindlimbs comparatively longer, with heels meeting or overlapping in M. cheni , M. boettgeri , M. kuatunensis , M. jinggangensis and M. lini ), tibio-tarsal articulation reaching the region between tympanum and eye when hindlimb is stretched along the side of the body (vs. reaching forward to the shoulder in M. brachykolos and to the posterior edge of tympanum in M. insularis ).

From the remaining 10 species occurring in China, Megophrys dongguanensis sp. nov. can be distinguished by the presence of vomerine teeth (vs. absent in M. binchuanensis , M. leishanensis , M. minor , M. tuberogranulatus , M. wuliangshanensis and M. wushanensis ), by the unnotched tongue (vs. tongue notched in M. daweimontis , M. liboensis , M. minor and M. rubrimera ), by the absence of lateral fringes on toes (vs. wide in M. binchuanensis , M. liboensis , M. palpebralespinosa and M. wushanensis (in males); narrow in M. rubrimera ), by the rudimentary webbing on toes (vs. toes without webbing in M. rubrimera and M. wuliangshanensis ; at least one-fourth webbed in M. palpebralespinosa ), by the heels not meeting when the flexed hindlimbs are held at right angles to the body axis (vs. heels meeting in M. binchuanensis and M. tuberogranulatus ; heels meeting or overlapping in M. minor and M. wushanensis ; heels overlapping in M. leishanensis , M. liboensis , M. palpebralespinosa and M. wuliangshanensis ).

Megophrys dongguanensis sp. nov. differs from the remaining species, M. fansipanensis , M. hoanglienensis and M. latidactyla , by the small horn-like tubercle at edge of upper eyelid (vs. slightly large in M. latidactyla ), by the unnotched tongue (vs. tongue notched in M. fansipanensis , M. hoanglienensis and M. latidactyla ), by the absence of lateral fringes on toes (vs. wide in M. latidactyla ), by the presence of rudimentary webbing on toes (vs. webbing indistinct or absent in M. fansipanensis and M. hoanglienensis ).

Megophrys dongguanensis sp. nov. further differs from M. feii , for which molecular data are lacking and cannot be allocated to any subgenus base on morphology only ( Yang et al. 2018) by the larger body size, SVL 30.2-39.3 mm in males (VS. 24.3-25.1 mm in males), presence of nuptial pad with nuptial spines in males during breeding season (vs. absent), presence of vomerine teeth (vs. absent), unnotched tongue (vs. slightly notched), absence of lateral fringes on toes (vs. moderate or wide), heels not meeting when the flexed hindlimbs are held at right angles to the body axis (vs. heels overlapping).

Description of holotype.

Adult male. Body moderate-sized, SVL 38.0 mm; head width slightly larger than head length, HWD/HDL 1.09; snout pointed in dorsal view, projecting, sloping backward to mouth in profile, protruding well beyond margin of lower jaw; top of head flat; eye large, ED/HDL 0.40, pupil vertical; nostril oblique ovoid; canthus rostralis well developed, forming the beginning of a fleshy, protruding ridge, that continues over the upper eyelid, and transitions into a supratympanic fold that terminates in the scapular region; loreal region slightly oblique; internasal distance slightly larger than interorbital distance; tympanum distinct, moderate-sized, TD/ED 0.54; large ovoid choanae at the base of the maxilla; presence of vomerine ridge bearing vomerine teeth; margin of tongue not notched posteriorly; internal vocal slits present near the rear of the lower mandible.

Radioulna length and hand length 0.24 of SVL; fingers without webbing and lateral fringes, relative finger length II <I <IV <III; tips of fingers slightly dilated, round; presence of subarticular tubercles on finger III, and one subarticular tubercle at the bases of each finger; outer metacarpal tubercles indistinct, inner metacarpal tubercles distinct and observably enlarged. Hindlimbs short, tibio-tarsal articulation reaching the region between tympanum and eye when hindlimb is stretched along the side of the body; heels not meeting when the flexed hindlimbs are held at right angles to the body axis; tibia length 0.41 of SVL and foot length 0.61 of SVL; relative toe length I <II <V <III <IV; tips of toes round and slightly dilated; presence of rudimentary webbing on toes but absence of lateral fringes and tarsal folds; one subarticular tubercle at the bases of each toe; presence of a long ovoid inner metatarsal tubercle and absence of outer metatarsal tubercle.

Dorsal skin texture rough with dense granules; granules forming discontinuous X-shaped ridge with two discontinuous dorsolateral ridges on both sides at the central trunk; several large tubercles present on dorsal surface of flanks, thighs, shanks and forearms; four small tubercles present on the edge of upper eyelid, one of which is more prominent; distinct narrow supratympanic fold curving posteroventrally from posterior corner of eye to a level above insertion of arm; ventral skin texture smooth, several granules present on surface of abandon, ventral and posterior surface of thighs; pectoral gland small, closer to axilla; single femoral gland on rear of thigh.

Measurements of holotype (in mm).

SVL 38.0, HDL 12.0, HDW 13.1, SNT 4.5, IND 3.9, IOD 3.6, ED 4.8, TD 2.6, TED 2.1, HND 9.1, RAD 9.2, FTL 23.2, TIB 15.6.

Coloration of holotype in life.

(Fig. 3 A–E) Yellowish brown dorsally, with a dark triangular marking between eyes. A wide oblique black band present on forearm. Dorsal surface of fingers and hindlimbs with dark grey transverse bands. Point of snout dark brown, presence of a vertical dark brown band below the eye. Tubercles on the edge of upper eyelid reddish. Supratympanic fold whitish tan. Ventral surface dark brown, with a black longitudinal band on surface of throat, several white spots present on ventral surface of limbs. Digits, inner and outer metacarpal tubercles greyish white, inner metatarsal tubercle greyish brown. Pectoral glands and femoral glands white. Iris yellowish brown.

Coloration of holotype in preservative.

Yellowish brown fades to greyish brown dorsally. Triangular marking between eyes, oblique bands on dorsal forearms, transverse bands on dorsal fingers and hindlimbs become indistinct. Color of ventral surface fades, all bands and spots become indistinct.

Variation.

Measurements of type series are listed in Table 4. All paratypes are very similar to holotype in morphology and color pattern. However, one male (SYS a001492) has more distinct skin ridges, granules and tubercles on dorsal surface of body (Fig. 3, F).

Etymology.

The specific epithet “dongguanensis” is in reference to the type locality, Dongguan City of the new species. We propose the common English name "Dongguan Horned Toad" and Chinese name "Dong Guan Jiao Chan ( 东莞角蟾)”.

Distribution and natural history.

Currently, Megophrys dongguanensis sp. nov. is only known from Mt. Yinping, Guangdong Province, China. It inhabits flowing montane streams and the nearby forest floor and leaf litter at elevations between 100-300 m. Advertisement calls of males were noticed from mid-December until April of the next year just before the rainy season. Males were found calling on rocks in the flowing streams. Tadpoles could be found in this period.