Nidirana yaoica, Lyu, Zhi-Tong, Mo, Yun-Ming, Wan, Han, Li, Yu-Long, Pang, Hong & Wang, Ying-Yong, 2019

Lyu, Zhi-Tong, Mo, Yun-Ming, Wan, Han, Li, Yu-Long, Pang, Hong & Wang, Ying-Yong, 2019, Description of a new species of Music frogs (Anura, Ranidae, Nidirana) from Mt Dayao, southern China, ZooKeys 858, pp. 109-126 : 109

Nidirana yaoica sp. nov.

Chresonymy.

Nidirana adenopleura : Fei et al. 2009 (Mt. Dayao, Jinxiu, Guangxi); Mo et al. 2014 (Jinxiu, Guangxi)

Holotype.

SYS a007022 (Fig. 3), adult male, collected by Zhi-Tong Lyu on 1 June 2018 from Mt Dayao (24.1602N, 110.2304E; ca 1190 m a.s.l.), Jinxiu Yao Autonomous County, Guangxi Zhuang Autonomous Region, China.

Paratypes. SYS a007009 , 7011-7013 , 7020-7021 , SYS a007014 / CIB 110013 , seven adult males collected by Zhi-Tong Lyu, Yu-Long Li and Cheng-Yu Yang on 30 May– 1 June 2018 from the same locality as the holotype. NHMG 1503043-47 , five adult males collected by Yun-Ming Mo and Wei-Cai Chen on 19 March 2015 from the neighboring locality as the holotype (24.1035N, 110.2294E; ca 1350 m a.s.l.).

Etymology.

The specific name yaoica is an adjective derived from Yao, referring to the type locality of the new species, Mt Dayao in Jinxiu Yao Autonomous County, where the settlement of the Yao people is located. We suggest its English common name to be Mt Dayao music frog and its Chinese name Yao Qin Wa (瑶琴蛙).

Differential diagnosis.

Nidirana yaoica sp. nov. is distinguished from its congeners by the following combination of the morphological characteristics: (1) body medium-size and stocky, with SVL 43.8 ± 1.7 (40.4-45.9, n = 13) mm in adult males; (2) disks of digits dilated, pointed; (3) lateroventral grooves present on every digit; (4) heels overlapping; (5) tibio-tarsal articulation reaching at the nostril; (6) mid-dorsal stripe present; (7) posterior of dorsal skin rough with dense tubercles but without spinules; (8) week supernumerary tubercles below the base of fingers III and IV, palmar tubercles prominent and distinct; (9) a pair of subgular vocal sacs present; (10) one single nuptial pad present on the first finger, nuptial spinules invisible; (11) suprabrachial gland large; (12) calling: 1-3 fast-repeated regular notes.

Description of holotype.

Adult male. Body stocky, SVL 44.6 mm; head longer than wide (HDW/HDL 0.92), flat above; snout rounded in dorsal and lateral views, slightly protruding beyond lower jaw, longer than horizontal diameter of eye (SNT/ED 1.26); canthus rostralis distinct, loreal region concave; nostril round, directed laterally, closer to the snout than to the eye; a longitudinal swollen mandibular ridge extending from below nostril through lower edges, eye and tympanum to above insertion of arm, where the ridge is intermittent, forming a maxillary gland and shoulder gland; supratympanic fold absent; interorbital space flat, narrower than internasal distance (IND/IOD 1.37); pupil elliptical, horizontal; tympanum distinct, round, TD/ED 0.72, and close to eye, TED/TD 0.38; pineal ocellus present; vomerine ridge present, bearing small teeth; tongue large, cordiform, notched behind.

Forelimbs moderately robust, lower arm 19% of SVL and hand 27% of SVL; fingers thin, relative finger lengths II <I <IV <III; tip of each finger slightly dilated and remarkable elongated, forming long pointed disks; well-developed lateroventral grooves on all fingers, not meeting at the tip of disks; fingers free of webbing; presence of weak lateral fringes on inner and outer sides of fingers II, III and IV, and on outer side of finger I; subarticular tubercles prominent and rounded; week supernumerary tubercles below the base of fingers III and IV; three elliptic, large, prominent and very distinct palmar tubercles.

Hindlimbs relatively robust, tibia 53% of SVL and foot 78% of SVL; heels overlapping when hindlimbs flexed at right angles to axis of body; tibio-tarsal articulation reaching the nostril when hindlimb is stretched along the side of the body; toes relatively long and thin, relative lengths I <II <V <III <IV; tip of each toe slightly dilated with remarkable elongated ventral callous pad, forming long and pointed disk; well-developed lateroventral grooves on toes, not meeting at the tip of disks; webbing moderate, webbing formula: I 2 - 2½ II 1⅔ - 3 III 2⅓ - 3½ IV 3½ - 2 V; presence of lateral fringes on inner and outer sides of each toes, forming distinct dermal flap on the lateral edges of toes I and V; subarticular tubercles rounded, prominent; inner metatarsal tubercle elliptic, twice as long its width; outer metatarsal tubercle indistinct, small and rounded; tarsal folds and tarsal tubercle absent.

Dorsal skin of head and anterior body smooth, posterior dorsum of body rough with dense tubercles but not bearing horny spinules; developed dorsolateral fold from posterior margin of upper eyelid to above groin but intermittent posteriorly; flank relatively smooth with dense tubercles on region nearly the dorsolateral fold; a large and smooth suprabrachial gland behind base of forelimb, slightly prominent; dorsal surface of upper arm with two longitudinal ridges and slightly extending to lower arm; the dorsal surfaces of thigh and tibia with several longitudinal ridges and tubercles bearing spinules. Ventral surface of head, body, and limbs smooth; large flattened tubercles densely arranged on the rear of thigh and around vent.

Color in life of holotype.

Dorsal surface of head and body reddish brown; pineal ocellus yellowish; a longitudinal reddish brown mid-dorsal stripe edged with broad dark brown, beginning from snout, across pineal ocellus, posteriorly extending to vent; several black spots on upper eyelids and posterior dorsum of body; dorsolateral fold bicolor, upper part reddish brown and lower part black; upper flank yellowish brown with irregular black spots; lower flank yellowish white; suprabrachial gland yellowish brown. Dorsal forelimbs reddish brown; a longitudinal black stripe on the anterior surface of the forelimb; irregular black marks on dorsal surface of the forelimb; dorsal hindlimbs non-uniform dark brown, four black crossbars on the thigh, three on the tibia and three on the tarsus; irregular black marks on dorsal toes. Loreal and temporal regions black, tympanum dark brown; upper ⅓ iris bright brownish white and lower ⅔ iris reddish brown; maxillary gland and shoulder gland yellowish white. Lips and throat grey white, but two subgular vocal sacs slightly dark colored; ventral surface of body and limbs creamy white; rear thigh tinged with pink; ventral hand and foot pale white with large black patches.

Color in preservative of holotype.

Dorsal surface faded, but dark brown edges of the mid-dorsal stripe more distinct; black spots on dorsum more distinct; upper flank black; limbs faded, the crossbars clearer; ventral surface faded, throat and posterior of chest with smoky gray markings.

Variations.

Measurements of type series are given in Table 3. All specimens were similar in morphology. Dorsal surface light brown in SYS a007009 (Fig. 4A), 7011, 7013 and 7020; mid-dorsal stripe begins from pineal ocellus in SYS a007011, 7013, 7014, 7020 and 7021 (Fig. 4B), unclear in SYS a007009; pineal ocellus invisible in SYS a007009.

Male secondary sexual characteristics.

A pair of subgular vocal sacs, a pair of slit-like openings at posterior of jaw; a single light brown nuptial pad on the dorsal surface of first finger, nuptial spinules invisible; suprabrachial gland present.

Distribution and ecology.

Currently, Nidirana yaoica sp. nov. is known only from the type locality, Mt Dayao, Jinxiu, Guangxi, in southern China. This frog inhabits in the swamps and ponds surrounded by moist subtropical secondary evergreen broadleaved forests (Fig. 4C, D). The adult male calls in the brushwood at the bank, from mid-March to late May. Nevertheless, the females, tadpoles, and much of the ecology and behavior of this species remain unknown.

Vocalization.

The call spectrograms are shown in Fig. 5 and the measurement parameters are listed in Table 4. The advertisement call (n = 87) of Nidirana yaoica sp. nov. contains 1-3 rapidly repeated, identical, regular notes with the PF of 516.8 Hz and note IQR-BW of 172.3 Hz or 0 generally. The one-note call (n = 25) has a duration of 43.3 ± 2.7 ms with the rise time of 10.1 ± 4.5 ms. The two-note call (n = 59) has a duration of 355.9 ± 31.1 ms; the first note lasts 43.5 ± 2.8 ms with the rise time of 8.5 ± 4.6 ms, and the second lasts 39.6 ± 3.3 ms with the rise time of 11.6 ± 4.4 ms; the note interval last 272.8 ± 31.7 ms.