Rhacophorus hongchibaensis, Li & Liu & Chen & Wu & Murphy & Zhao & Wang & Zhang, 2012

Li, Jia-Tang, Liu, Jun, Chen, Yue-Ying, Wu, Jia-Wei, Murphy, Robert W., Zhao, Er-Mi, Wang, Yue-Zhao & Zhang, Ya-Ping, 2012, Molecular phylogeny of treefrogs in the Rhacophorus dugritei species complex (Anura: Rhacophoridae), with descriptions of two new species, Zoological Journal of the Linnean Society 165 (1), pp. 143-162 : 150-154

RHACOPHORUS HONGCHIBAENSIS SP. NOV.

( FIGS 1 , 2 , 3B, D , 4 ; TABLE 3)

Holotype: CIB 97687 ( Fig. 3D , Table 3), an adult male, collected on 17 May 2006 by Jia-tang Li and Jian-li Xiong from Hongchiba, Wuxi County, Chongqing, China (31°32′26.92″ N, 109°03′51.19″ E, elevation 1747 m a.s.l.; Fig. 1 ).

Paratype: CIB 97688, an adult female, and CIB 97694–97698 , five males, collected together with the holotype .

Diagnosis: Rhacophorus hongchibaensis sp. nov. can be distinguished from all other species in the genus by a combination of the following attributes: (1) range of body size (SVL) of males, 46.5–49.7 mm, SVL of females 55.3 mm; (2) ratio between TIL and SVL 0.372, alternatively, when adpressed to the body, tibiotarsal articulation does not reach tympanum; (3) light-green dorsal colour, with numerous large spots of light yellowish brown edged with vague darkbrown border; (4) hand length and forelimb length relatively short, HLT/SVL (0.313 –0.368), FLL/SVL (0.480 –0.569); (5) third finger width larger than tympanum; (6) dorsum with weakly distributed granules.

Description of holotype: An adult male, SVL 47.4 mm; head width slightly greater than length (HW 17.2 mm; HL 15.3 mm); snout 7.0 mm, slightly pointed in dorsal view, larger than diameter of eye (ED 5.6 mm); top of head flat; IOD smaller than IND (IOD 4.5 mm; IND 5.1 mm); canthus rostralis obvious; loreal region slightly concave; tympanum distinctly visible, rounded, about 0.5 ¥ ED (TD 2.7 mm); vomerine processes, with three teeth each; vocal sac single, externally expanded; tongue cordiform, distinctly notched posteriorly, free for approximately one-quarter of its length.

Forelimb 25.1 mm; hand length (HLT 16.3 mm), over half length of forelimb; finger with lateral dermal fringe, relative lengths of fingers 3> 4> 2> 1 (FL 1 8.0 mm; FL 2 11.3 mm; FL 3 16.3 mm; FL 4 13.2 mm); discs expanded, with circummarginal groove at the end of phalanges; terminal phalanges Y-shaped; pad length (III) smaller than pad width (3FL 2.6 mm; 3FW 3.1 mm), 3FW larger than TD; hand webbed developed only at base, webbing formula for digits following Myers & Duellman (1982), I trace–II2–3III2.5–2IV; subarticular tubercles circular and distinctly convex; inner metacarpal tubercles small, indistinct.

Hindlimb relatively short; when adpressed to the body tibiotarsal articulation does not reach tympanum; heels do not meet when folded at right angle to body; thigh length larger than tibia length (THL 19.0 mm; TIL 17.0 mm); foot length larger than tibia length; toes with lateral dermal fringe, relative length of toes 4> 5> 3> 2> 1 (TL 1 8.1 mm; TL 2 11.2 mm; See text for a list of definitions for the measurements.

TL 3 15.4 mm; TL 4 20.9 mm; TL 5 16.0 mm); discs round ventral circummarginal groove, 4TW (2.60 mm) slightly smaller than TD; feet one-third webbed, webbing formula for digits I1–2II1.5–2III2–3IV3– 2V; subarticular tubercles moderately prominent, rounded; inner metatarsal tubercle small, oval, and indistinct.

Skin on dorsum of body and surface of limbs weakly granulated, becoming feeble or with weak tubercles on sides of body; belly grossly granulate; ventral surface of limbs areolate.

Colour in life: The dorsal and lateral surface light green, with numerous large spots of light yellowish brown with vague dark-brown border; upper surface of forelimb and hindlimb same as dorsum; dorsal colour of hands and feet yellowish brown, with numerous dark-brown spots; ventral surface creamy white with vaguely greyish brown blotches; ventral sides of the hindlimbs lightly red, marbled with grey; tips of fingers light brown with scattered dark mottling; inner side colour of thigh is creamy white with vague brown spots ( Fig. 3B ).

Colour in preservative: Dorsal and lateral colours black–brown; ventral surface light creamy yellow, with vague, light-greyish brown blotches ( Fig. 3D ). Posterior colour of thigh and arm dark brown with numerous black blotches; inner side colour of tibia white with vague brown spots.

Variation: Measurements and ranges of seven specimens from the type series are listed in Table 3. Males (46.5–49.7 mm) smaller than female (55.3 mm). Tip of the snout in males is rather pointed compared with females. Males with internal subgular vocal sacs and two sublingual openings; nuptial pad present on the base of the first finger in males during breeding season. Numbers of vomerine teeth vary as follows: CIB 097688 , CIB 097694 , CIB 097695 , CIB 097696 , and CIB 097698 with four teeth each; CIB 097697 with five teeth. Webbing formula, with range in parentheses, based on Myers & Duellman (1982): fingers, I trace–II2–3 III2.5 –(2–3)IV; toes, I(1–1.75)–2II(1–2)– (2–2.5) III2 –(2–2.5)IV(2–3)–(1–2) V. Some specimens have fewer spots on the dorsum and ventrum .

Etymology: The species epithet of R. hongchibaensissp . nov. is named for the type locality, Hongchiba, which is the largest alpine grassland in southern China ( He et al., 2004).

Comparisons: Rhacophorus hongchibaensis sp. nov. is assigned to the genus Rhacophorus , and is excluded from all other genera by the following suite of characters: terminal phalanges Y-shaped, discs expanded, intercalary element present, and webbing between fingers and toes ( Liem, 1970; Wilkinson & Drewes, 2000). The molecular phylogeny confirms the assignment.

Following the taxonomic designations in Frost (2011), R. hongchibaensis sp. nov. can be readily distinguished from other species of the genus from Cambodia, China, India, Indonesia, Laos, Malaysia, Myanmar, Thailand, and Vietnam. It differs from most of the other species of Rhacophorus in not having calcanar projections, which are present in Rhacophorus annamensis Smith, 1924 , Rhacophorus bipunctatus Ahl, 1927 , Rhacophorus calcaneus Smith, 1924 , Rhacophorus chuyangsinensis Orlov, Nguyen & Ho, 2008 , Rhacophorus kio Ohler & Delorme, 2005 , Rhacophorus lateralis Boulenger, 1883 , Rhacophorus malabaricus Jerdon, 1870 , Rhacophorus nigropalmatus Boulenger, 1895 , Rhacophorus orlovi Ziegler & Köhler, 2001 , Rhacophorus pardalis Günther, 1858 , Rhacophorus reinwardtii (Schlegel, 1840) , Rhacophorus rhodopus Liu & Hu, 1959 , Rhacophorus translineatus Wu, 1977 , and Rhacophorus verrucopus Huang, 1983 ( Wilkinson et al., 2005; Orlov, Nguyen & Ho, 2008). The presence of one-third webbing on the toes distinguishes the new species from those that have full webbing, including Rhacophorus burmanus (Andersson, 1939) , Rhacophorus dennysi Blanford, 1881 , Rhacophorus duboisi Ohler, Marquis, Swan & Grosjean, 2000 , Rhacophorus dulitensis Boulenger, 1892 , Rhacophorus feae Boulenger, 1893 , Rhacophorus maximus Günther, 1858 , and Rhacophorus omeimontis (Stejneger, 1924) ( Liem, 1970; Jiang et al., 1987; Fei, 1999; Wilkinson & Drewes, 2000; Fei et al., 2009, 2010). The light-yellowish brown spots edged with dark brown on the dorsum clearly separates the new species from Rhacophorus arboreus (Okada & Kawano, 1924) , Rhacophorus chenfui Liu, 1945 , Rhacophorus dorsoviridis Bourret, 1937 , R. hungfuensis , R. minimus , Rhacophorus moltrechti Boulenger, 1908 , Rhacophorus nigropunctatus Liu, Hu & Yang, 1962 , Rhacophorus schlegelii (Günther, 1858) , and Rhacophorus yaoshanensis Liu & Hu, 1962 , the latter species with green dorsum ( Liem, 1970; Jiang et al., 1987; Fei, 1999; Wilkinson et al., 2005; Fei et al., 2009, 2010; Appendix 2).

Male R. hongchibaensis sp. nov. differ from similar appearing Chinese species in the R. dugritei complex ( R. dugritei , R. hui , R. hungfuensis , R. minimus , R. puerensis , and R. wui sp. nov.) by their relatively large body size (46.5–49.7 mm) ( Fig. 3B ) and relatively lower ratio between TIL and SVL (0.372) ( Table 4). The PCA results confirm these differences ( Fig. 4 ; Appendix 2).

Distribution and ecology: The new species is known only from the type locality. It shares a similar

*The mean difference is significant at the 0.05 level. ecological environment in high-altitude localities with the species R. dugritei , R. wui sp. nov. ( Fig. 3E ), R. hui , and R. puerensis . Both solitary males and amplexing pairs are found at night during the mating season, from March through June. Males perch on vegetation near either the ground or water. White foam nests with fertilized eggs occur at the bottom of grassy vegetation near swampy pools. Males call both day and night, although predominately at night. The call is a loud ‘der-der-der’ sound.

Figures

Figure 1. Collection sites of species in this study. Red star and triangle represent the type localities of Rhacophorus hongchibaensis sp. nov. and Rhacophorus wui sp. nov., respectively. Red circles, plus the star and triangle, indicate the sample sites of the Rhacophorus dugritei species complex. Brown symbols represent collection sites of all species, except for those of the Rhacophorus dugritei species complex. The detailed information represented by Arabic numbers is shown in Table 2. The blue, red, and purple circles indicate lineages A, B, and C of Figure 2, respectively.

Figure 2. The 50% majority rule consensus tree from a Bayesian inference analysis of partial fragments of mitochondrial (12S rRNA, valine tRNA, and 16S rRNA) and nuclear (tyrosinase and rhodopsin) genes. Black circles indicate nodes supported by Bayesian posterior probabilities (BPP) ± 0.90, and maximum likelihood bootstrap proportions (MLBS) and maximum parsimony bootstrap proportions (MPBS) ± 70%. Grey circles indicate poorly supported nodes (BPP <0.90; MLBS and MPBS <70%).

Figure 3. A, an amplexing pair of Rhacophorus wui sp. nov. in life. B, Rhacophorus hongchibaensis sp. nov. in comparison with Rhacophorus dugritei and Rhacophorus puerensis: 1, R. hongchibaensis sp. nov., adult male; 2, R. puerensis, adult male; 3, R. dugritei, adult male; 4, R. hongchibaensis sp. nov., adult female; 5, R. dugritei, adult male. C, dorsal views of the male holotype of R. wui sp. nov. (CIB 97685). D, dorsal views of the male holotype of Rhacophorus hongchibaensis sp. nov. (CIB 97687). E, habitat of R. wui sp. nov. in Hanchi Village, Lichuan County, Hubei, China.

Figure 4. Principal components analysis (PCA) scores of Rhacophorus dugritei, Rhacophorus hongchibaensis sp. nov., Rhacophorus hungfuensis, Rhacophorus hui, Rhacophorus minimus, Rhacophorus puerensis, and Rhacophorus wui sp. nov.