Liuixalus feii, Yang, Jian-Huan, Rao, Ding-Qi & Wang, Ying-Yong, 2015

Yang, Jian-Huan, Rao, Ding-Qi & Wang, Ying-Yong, 2015, A new species of the genus Liuixalus (Anura: Rhacophoridae) from southern China, Zootaxa 3990 (2), pp. 247-258 : 251-255

Liuixalus feii sp. nov.

Holotype. SYS a002389, adult male, from Heishiding Nature Reserve, Fengkai County, Guangdong Province, China (23°27'10.4'' N, 111°53'15.4'' E, 550 m a.s.l.; Fig. 2 ), collected by Yu-Long Li and Jian Zhao at night on 6 October 2013.

Paratypes. Four adult males and two adult females from the same locality as holotype: SYS a000454, adult female, collected by Jian-Huan Yang on 29 May 2009; SYS a002158, adult male, collected by YLL and JZ on 1 June 2013; SYS a002388, adult female, and a002390, adult male, same data as holotype; SYS a003049–3050, adult males, collected by Ying-Yong Wang and Zu-Yao Liu on 15 July 2014.

Etymology. The specific epithet “ feii ” is a patronymic noun in the genitive singular; derived from the name of Professor Liang Fei of the Chengdu Institute of Biology, Chinese Academy of Sciences, China, in recognition of his long-term great contribution to the advancement of amphibian research in China. For the common name, we suggest “Fei’s Small Tree Frog” in English, “Fei Shi Xiao Shu Wa” in Chinese.

Diagnosis. The new species is assigned to the genus Liuixalus by presenting the following characters: body size small; tympanum well distinct and about half the eye diameter; fingers without webbing; toes weakly webbed; hindlimb relatively long, tibio-tarsal articulation reaching the naris or loreal; discs on the digits well developed, discs of toes slightly smaller than disks of fingers; dorsum of body with a X-shaped marking ( Milto et al. 2013). Liuixalus feii sp. nov. is distinguished from its congeners by a combination of following characters: small size (SVL 16.2–17.6 mm in adult males and 18.0– 18.7 mm in adult females); snout obtusely pointed; tympanum distinct, about half size of eye diameter; nostril closer to eye than to the tip of snout; fingers free of webbing; toe III longer than toe V; toes weakly webbed; tibiotarsal articulation reaching the naris or loreal; dorsal skin smooth and scattered with fine granulars; a subtle longitudinal median ridge present on dorsum; weak skin folds present on dorsal surface of body and thighs; supratympanic fold distinct and curved; ventral surface dull white with more or less irregular dark spots; iris bicolored.

Description of holotype. SYS a002389, adult male, body size small (SVL 16.8 mm), head length slightly greater than head width (HL 6.6 mm; HW 5.7 mm); snout obtusely pointed in dorsal view and profile, projecting beyond margin of the lower jaw; interorbital region flat; canthus rostralis distinct and rounded; loreal region slightly oblique and concave; nostrils oval, slightly protuberant, slightly closer to eye than to tip of snout; interorbital distance slightly greater than internasal distance; pupil horizontal; tympanum distinct, 48.0% of eye diameter, distant from eye by half of its own diameter (ratio of TED/TD 0.5); tympanic rim weakly elevated relative to skin of temporal region; interorbital distance wider than the upper eyelid; pineal ocellus absent; vomerine teeth absent; choanae rounded, at margins of mouth roof; tongue oblong, attached anteriorly and notched posteriorly; supratympanic fold distinct and somewhat curved, extending from behind eye to shoulder basis.

Forelimbs moderately robust, relative length of fingers I <II <IV <III ( Fig. 3 D); tips of fingers II, III, IV with well-developed disks with distinct circummarginal grooves, disks relatively wide compared to finger width (disk of finger III 216% wider than width of finger III), third finger disk width 68.4% of tympanum diameter; tip of finger I round and without distinct disk; fingers free of webbing; subarticular tubercles prominent, rounded, formula 1, 1, 2, 2; outer palmar tubercle weakly divided into two; accessory palmar tubercles indistinct; no nuptial pads observed on dorsal surface of fingers.

Hindlimbs long and slender, 171% of SVL; tibiotarsal articulation reaching the naris when adpressed along the body; tibia length 54% of SVL; relative length of toes I <II<V <III <IV ( Fig. 3 E); tips of toes with poorly developed disks with distinct circummarginal grooves, disks smaller than those of fingers; toe weakly webbed, webbing formula I 2–2 ½ II 2–3 ¼ III 2 ⅓–4 IV 3 ⅓–1¾ V; subarticular tubercles distinct, rounded, formula 1, 1, 2, 3, 2; inner metatarsal tubercle low, oval, distinct, approximately 0.8 mm in length; outer metatarsal tubercle very small and indistinct.

Dorsal surface of head and body smooth and scattered with fine granules, those on flanks and eyelids somewhat prominent; a subtle longitudinal median ridge present on dorsum; weak skin folds present on dorsal surface of body and thigh; ventral surface of thighs and abdomen with flat granules, throat smooth.

Coloration of holotype in preservative. Dorsal surface pale brown with a dark X-shaped marking from behind the eyes, consisting of two crooked dark lines along body not in contact medially; a dark interorbital narrow bar between the eyes extending to the upper eyelids; dark transverse bars present on dorsal surface of fore and hind limbs: two on the lower arm, four on the thigh, three on the tibia; ventral surface dirty-white, scattered with few irregular dark spots on chest and venter; lateral of head dark brown, supratympanic fold distinctly darker; lower lip pale white with conspicuous dark bars; a remarkable dark blotch present on the anterior portion of shoulder joint; iris bicolored, upper third pale white, lower two third dark brown.

Variation. All six paratypes match the overall characters of the holotype (measurements of type series see Table 3 ). All type specimens have a dark X-shaped marking on dorsum composed of two crooked dark lines, these lines are usually separated but are in contact medially in SYS a002158; the dark spots on the ventral surface are somewhat distinct in SYS a002388, 2390, 3049, 3050 (see Figs. 3–5 for coloration variation). No significant differences between males and females were revealed, however females are slightly larger than males (SVL 18.0– 18.6 mm versus 16.2–17.6 mm). Of the five males, only SYS a003050 possesses distinct nuptial pad on the posterodorsal surface of finger I.

Distribution and natural history. The new species, Liuixalus feii sp. nov., is currently known from Heishiding Nature Reserve, Fengkai County, Guangdong Province, China ( Fig. 2 ). All individuals recorded were found on leaf-litter on the forest floor in well-preserved primary forest at elevations between 350– 800 m.

In its type locality, calls of males of Liuixalus feii sp. nov. have been heard from April to October. A small tree hole in the roots of a large tree (the hole opening approximately 28 mm wide, 64 mm high and 78 mm deep; water depth inside the hole about 20 mm), 10 cm above the ground, was found containing eight free-swimming tadpoles on 2 May 2010, as well as an adult male calling nearby. We assume these to belong to the new species, but have not confirmed it. All individuals of the new species were found on the forest floor and not closed to streams or pools; and no individual was recorded along the streams, ponds or other kinds of wetlands during our surveys in the nature reserve. Therefore, the new species appears to be a forest-dependent species and is likely a phytotelmbreeder, breeding in water accumulated in tree or bamboo holes in the forest.

Comparisons. Liuixalus feii sp. nov. differs from L. calcarius by having nostril closer to eye than to tip of snout (reverse condition in L. calcarius ); tibiotarsal articulation reaching the naris (versus beyond the tip of snout in L. calcarius ); toe III longer than toe V (versus toe III length equal to toe V in L. calcarius ); throat of males dull white (versus dark colored in males in L. calcarius ). Liuixalus feii sp. nov. differs from L. hainanus by having a relatively smaller tympanum in males (mean ratio of TD/SVL 0.056 in L. feii sp. nov. versus 0.081 in L. hainanus ); relatively shorter hindlimbs in males (mean ratio of HLL/SVL 1.65 in L. feii sp. nov. versus 1.68 in L. hainanus ); relatively shorter tibias in males (mean ratio of TIB/SVL 0.53 in L. feii sp. nov. versus 0.64 in L. hainanus ); tibiotarsal articulation reaching the naris (versus beyond the tip of snout in L. hainanus ); the absence of beige speckling on the dorsum (versus present in L. hainanus , Fig. 6 ); the distinct difference in eye color pattern (iris bicolor in L. feii sp. nov. versus iris yellowish overall with distinct small dark spots above and below pupil in L. hainanus ). Liuixalus feii sp. nov. differs from L. ocellatus by having relatively smaller tympanum in males (mean ratio of TD/SVL 0.056 in L. feii sp. nov. versus 0.078 in L. ocellatus ); relatively shorter snout (mean ratio of SL/ SVL 0.15 in L. feii sp. nov. versus 0.18 in L. ocellatus ); relatively longer hindlimbs in males (mean ratio of HLL/ SVL 1.66 in L. feii sp. nov. versus 1.63 in L. ocellatus ); tip of 1st finger not enlarged and without disk (versus with tip of 1st finger with distinct disk in L. ocellatus ). Liuixalus feii sp. nov. differs from L. romeri by having relatively smaller tympanum in males (mean ratio of TD/SVL 0.056 in L. feii sp. nov. versus 0.088 in L. romeri ); snout longer than eye diameter in males (mean ratio of ED/SL 0.85 in L. feii sp. nov. versus 1.07 in L. romeri ); tibiotarsal articulation reaching the naris (versus reaching the tip of snout in L. romeri ); fingers free of webbing (versus weakly webbing present between fingers III and V in L. romeri ); toes weakly webbed (versus toes 1/3 webbed in L. romeri ).

Figures

FIGURE 2. Map showing the distribution of of Liuixalus species and populations included for phylogenetic analyses in this study. 1: Wuzhishan NR, Hainan; 2: Diaoluoshan NR, Hainan; 3: Cat Ba Island, Vietnam; 4: Mt. Shiwan, Guangxi; 5: Heishiding NR, Guangdong; 6: Hong Kong.

FIGURE 3. Holotype SYS a 002389 of Liuixalus feii sp. nov. in preservative. A: dorsal view; B: ventral view; C: lateral view of head and body; D: ventral view of right hand; E: ventral view of left foot.

FIGURE 6. A: a male individual of Liuixalus feii sp. nov., photographed on 2 May 2010, not collected; B: L. hainanus from Diaoluoshan, NR Hainan (type locality); C: L. ocellatus from Wuzhishan NR, Hainan (type locality); D: L. romeri from Hong Kong (type locality); E: paratype of L. calcarius from Cat Ba Island, Vietnam; F: L. cf. romeri from Mt. Shiwan, Guangxi.

Tables

TABLE 3. Measurements (mm) of type specimens of Liuixalus feii sp. nov.. Abbreviations defined in text.

SYS a002158 sex Male	SYS a002389 Male	SYS a002390 Male	SYS a003049 Male	SYS a003050 Male	Mean ± SD (N=5)	SYS a000454 Female	SYS a002388 Female	Mean ± SD (N=2)
SVL 16.3 HL 6.2 HW 6.1	16.8 6.6 5.7	17.0 6.6 6.0	16.2 6.2 5.6	17.6 6.8 6.3	16.78±0.57 6.48±0.27 5.94±0.29	18.7 7.2 6.2	18.0 6.7 6.2	18.35±0.49 6.95±0.35 6.20±0.00
SL 2.4 IND 1.9 IOD 2.3	2.7 2.0 2.1	2.6 2.0 2.0	2.4 2.0 2.1	2.9 2.2 2.4	2.60±0.21 2.02±0.11 2.18±0.16	2.9 2.3 2.5	2.7 2.1 2.3	2.80±0.14 2.20±0.14 2.40±0.14
UEW 1.2 ED 2.0 TD 0.9	1.4 2.1 1.0	1.3 2.2 0.9	1.1 2.2 0.9	1.1 2.3 1.0	1.22±0.13 2.16±0.11 0.94±0.05	1.3 2.5 1.0	1.1 2.2 0.9	1.20±0.14 2.35±0.21 0.95±0.07
TED 0.6 LAHL 7.9 HAL 3.9	0.5 8.0 4.2	0.6 7.4 4.3	0.6 7.8 4.1	0.6 8.1 4.2	0.58±0.04 7.84±0.27 4.14±0.15	0.7 7.4 3.9	0.6 8.1 4.3	0.65±0.07 7.75±0.49 4.10±0.28
HLL 26.9 TIB 8.3 LFT 11.9	28.7 9.1 12.6	27.0 9.0 12.1	27.8 8.7 11.9	28.3 9.0 12.0	27.74±0.79 8.82±0.33 12.10±0.29	28.7 9.4 12.1	29.9 9.6 13	29.30±0.85 9.50±0.14 12.55±0.64
FT 7.3 FDW III 0.5 TDW IV 0.5	7.8 0.7 0.5	7.2 0.5 0.5	7.3 0.5 0.5	7.7 0.7 0.6	7.46±0.27 0.58±0.11 0.52±0.04	7.8 0.5 0.5	7.6 0.6 0.5	7.70±0.14 0.55±0.07 0.50±0.00
HL/SVL 0.38 HL/HW 1.02 SL/SVL 0.15	0.39 1.16 0.16	0.39 1.10 0.15	0.38 1.11 0.15	0.39 1.08 0.16	0.39±0.00 1.09±0.05 0.15±0.01	0.39 1.16 0.16	0.37 1.08 0.15	0.38±0.01 1.12±0.06 0.15±0.00
ED/SL 0.83 TD/ED 0.45 TED/TD 0.67	0.78 0.48 0.50	0.85 0.41 0.67	0.92 0.41 0.67	0.79 0.43 0.60	0.83±0.05 0.44±0.03 0.62±0.07	0.86 0.40 0.70	0.81 0.41 0.67	0.84±0.03 0.40±0.01 0.68±0.02
LAHL/SVL 0.48 HLL/SVL 1.65 TIB/SVL 0.51	0.48 1.71 0.54	0.44 1.59 0.53	0.48 1.72 0.54	0.46 1.61 0.51	0.47±0.02 1.65±0.06 0.53±0.01	0.40 1.53 0.50	0.45 1.66 0.53	0.42±0.04 1.60±0.09 0.52±0.02