Odorrana dulongensis, Liu & He & Wang & Beukema & Hou & Li & Che & Yuan, 2021

Liu, Xiaolong, He, Yanhong, Wang, Yufan, Beukema, Wouter, Hou, Shaobin, Li, Yingcun, Che, Jing & Yuan, Zhiyong, 2021, A new frog species of the genus Odorrana (Anura: Ranidae) from Yunnan, China, Zootaxa 4908 (2), pp. 263-275 : 269-272

Odorrana dulongensis sp. nov. Liu, Che and Yuan

( Fig. 3 –6)

Holotype. KIZ 035029 , adult male, Dulongjiang village , Gongshan county, Nujiang Prefecture, Yunnan Province, China, 27.677ºN, 98.271ºE, 1,206.1 m asl., coll. 27 June 2019 by Xiaolong Liu ( Fig. 1 ).

Paratypes. KIZ 035027–28 (males) , KIZ 035030 (female) , KIZ 035081 (male) , KIZ 035058 (female) from the same locality as the holotype by Xiaolong Liu and Yufan Wang .

Diagnosis. The species is allocated to the genus Odorrana based on its molecular phylogenetic placement. Odorrana dulongensis sp. nov. is distinguished from its congeners by a combination of (1) moderate body size (SVL of adult males ranges between 47.8–55.4 mm, that of females between 78.3–87.5 mm); (2) a grass-green dorsum with black spots on posterior region in both males and females; (3) absence of dorsolateral folds; (4) dorsal and lateral granular skin; (5) distinct transverse bands on the dorsal surfaces of limbs; (6) supratympanic fold distinct; (7) all toe discs expanded with lateroventral grooves; (8) outer metacarpal and outer metatarsal tubercle absent; (9) entire webbing formula I0–½II0+½III0+1IV1–0V; (10) head wider than long; (11) supernumerary tubercles absent; (12) a pair of external subgular vocal sacs; and (13) presence of a white nuptial pad on the base of finger I in adult males.

Description of the holotype. Adult male ( Figs. 3–5 ), habitus moderately slender (SVL= 52.6 mm); head width slightly shorter than length (HW/HL=0.86); snout slightly obtusely pointed in dorsal view and rounded in profile, projecting beyond lower jaw; position of nostril dorsolateral, closer to snout than eye; canthus rostralis distinct; loreal region concave and sloping; internarial distance greater than interorbital distance (IOD/IND=0.73); snout length greater than eye diameter; interorbital distance greater than upper eyelid width (SNL/UEW=1.39); pineal body visible; supratypanic fold distinct and slanted; tympanum distinct and shorter than eye diameter (TMP/EYE=0.54), tympanic rim slightly elevated relative to tympanum; vomerine teeth on two oblique ridges; choanae oval close to the vomerine teeth. Tongue cordiform, posterior notch enlarged and formed as U-shaped; vocal sac opening on floor of mouth at each corner; small sac-like gular pouch from corners of the mouth to corners of arms.

Forelimbs moderately robust ( Fig. 4 ); relative lengths of fingers I=II<IV<III; all finger tips expanded except for finger I, all finger tips with lateroventral (or circummarginal grooves) and dorsomarginal grooves; lateral fringes and webbing on fingers absent; subarticular tubercle prominent; supernumerary tubercle indistinct; one oval thenar tubercle prominent on the venteral of Finger I; outer metacarpal tubercle absent; white glandular nuptial pad on Finger I.

Hind limbs long, tibia longer than thigh (TFL/TIB=1.29) and foot (TFL/FTL=1.35); toes long and thin, relative lengths I<II<III<V<IV ( Fig. 5 ); tips of all toes expanded with transversely oval disks, lateroventral and dorsomarginal grooves; entire webbing formula I0–½II0+½III0+1IV1–0V; all subarticular tubercles prominent and longitudinally ovoid; inner metatarsal tubercle prominent and oval; outer metatarsal absent; supernumerary tubercles absent.

Dorsal and lateral skin granular, but dorsal surface of the head and ventral surfaces of the head, body, and limbs smooth. Dorsolateral folds absent.

Coloration of holotype. In life, dorsum grass-green with posterior black spots; flanks light-yellow with several black spots; dorsal surfaces of forelimbs olive brown, with black bands and irregular grass green spots; dorsal surfaces of hind limbs olive brown with black bands; nine black spots on the upper jaw; lower jaw yellow with seven black spots; grass green spots and black spots mosaic on the loreal region; ventral surface of throat, chest and belly immaculate. In preservative, the dorsum faded to dark olive; the olive brown surface of limbs faded to whitish-gray; grass-green spots on the loreal region and forelimbs faded to whitish-gray.

Morphological variation. Measurements of the holotype and paratypes are given in Table 2. Paratype KIZ 035081 and KIZ 035058 display light mottling on the throat. The amount of dorsal black spots vary between the paratypes .

Comparisons. Rather than comparing Odorrana dulongensis sp. nov. to all extant Odorrana , we focus our comparison below on phylogenetically closely related taxa, and those for which mitochondrial DNA sequence data is currently lacking.

Our molecular results place Odorrana dulongensis sp. nov. in a clade composed of O. andersonii , O. grahami , Odorrana jingdongensis Fei, Ye & Li 2001 , Odorrana kuangwuensis (Liu & Hu 1966) , O. margaretae , and O. wuchuaensis (see also Chen et al. 2013). Sequence divergence for the 16S rRNA gene between Odorrana dulongensis sp. nov. and these species ranges from 4.8–6.4% ( Table S2). Furthermore, Odorrana dulongensis sp. nov. differs from the aforementioned species by (i) lacking an outer metatarsal tubercle (vs. present in other species), (ii) absence of skin spines on the venter (vs. present in other species), and (iii) presence of a distinct a pair of external subgular vocal sacs in males, which are internal in O. andersonii , O. grahami , and O. jingdongensis , and absent in O. kuangwuensis , O. margaretae and O. wuchuaensis . Odorrana dulongensis sp. nov. further differs from O. grahami in showing expanded finger tips (except for finger I) and presence of expanded toes including lateroventral grooves (vs. finger tips and toes not expanded and lateroventral grooves absent in O. grahami ). From O. kuangwuensis , Odorrana dulongensis sp. nov. also differs by lacking spots on the toe and finger webbing (vs. present in O. kuangwuensis ).

From Odorrana species for which no molecular data are available, and that occupy distributions distant from that of Odorrana dulongensis sp. nov., differences are as follows. Odorrana dulongensis sp. nov. differs from Odorrana bolavensis ( Stuart & Bain 2005) by (i) lacking dorsolateral folds and its granular skin (vs. presence of distinct dorsolateral folds and shagreened dorsal skin in O. bolavensis ), and (ii) absence of white spinules on dorsal and ventral surfaces in males (vs. present in O. bolavensis ). Odorrana dulongensis sp. nov. differs from Odorrana gigatympana (Orlov, Ananjeva & Ho 2006) by (i) lacking dorsolateral folds and its granular skin (vs. presence of distinct dorsolateral folds and slightly rough skin with large tubercles in O. gigatympana ); (ii) absence of the outer metatarsal tubercle (vs. present in O. gigatympana ); (iii) males showing a larger SVL (47.8–55.4 mm vs. 30.1–35.7 mm in O. gigatympana ), and (iv) its grass-green dorsum with black posterior spots (vs. uniform brown or grey in O. gigatympana ). Odorrana dulongensis sp. nov. differs from Odorrana indeprensa (Bain & Stuart 2006) by (i) absence of white spinules on dorsal and ventral surfaces in males (vs. present in O. indeprensa ); (ii) a smaller SVL in females (78.3–87.5 mm vs. 92.8–101 mm in O. indeprensa ); and presence of black spots on the upper and lower lip (vs. absent in O. indeprensa ). Odorrana dulongensis sp. nov. differs from Odorrana mawphlangensis (Pillai & Chanda 1977) by (i) lacking dorsolateral folds and its granular skin (vs. presence of distinct dorsolateral folds and a granular dorsal skin with large glandular warts in O. mawphlangensis ); (ii) absence of supernumerary tubercles (vs. present in O. mawphlangensis ); (iii) presence of a distinct a pair of external subgular vocal sacs in adult males (vs. absent in O. mawphlangensis ), and (iv) distinct supratympanic folds (vs. indistinct in O. mawphlangensis ). Odorrana dulongensis sp. nov. differs from Odorrana monjerai ( Matsui & Jaafar 2006) by (i) lacking dorsolateral folds and its granular skin (vs. presence of distinct dorsolateral folds and finely tuberculated dorsal skin in O. monjerai ); (ii) a larger SVL in adult males (47.8–55.4 mm vs. 38.0–43.0 mm in O. monjerai ); and (iii) its grass-green dorsum with black posterior spots (vs. uniform brown or grey, and unspotted, in O. monjerai ). Odorrana dulongensis sp. nov. differs from Odorrana orba ( Stuart & Bain 2005) by (i) lacking dorsolateral folds and its granular skin (vs. presence of distinct dorsolateral folds and heavily shagreened dorsal skin in O. orba ); (ii) absence of supernumerary tubercles (vs. present in O. orba ); and (iii) absence of white spinules on upper and lower parts in males (vs. present in O. orba ).

From Odorrana species for which no molecular data are available, and that occur in the same geographical region as Odorrana dulongensis sp. nov., differences are as follows. Odorrana dulongensis sp. nov. differs from Odorrana cangyuanensis ( Yang 2008) , which occurs in Western Yunnan as well, by (i) a distinct a pair of external subgular vocal sacs in adult males (vs. internal in O. cangyuanensis ), (ii) its grass-green dorsum with black posterior spots (vs. uniform brown or grey, and unspotted, in O. cangyuanensis ); (iii) its relative lengths of fingers I=II<IV<III (vs. I<IV<II <III in O. cangyuanensis ); and (iv) presence of a white-colored nuptial pad on the base of Finger I in adult males (vs. presence of a gray-colored nuptial pad in male O. cangyuanensis ). Odorrana dulongensis sp. nov. differs from Odorrana macrotympana ( Yang 2008) , which occurs in Western Yunnan as well, by (i) lacking dorsolateral folds and its granular skin (vs. presence of distinct dorsolateral folds and smooth dorsal skin in O. macrotympana ); (ii) supratypanic fold slanted (vs. supratypanic fold flat in O. macrotympana ); (iii) its grassgreen dorsum with black posterior spots (vs. uniform brown or grey with spotted, in O. macrotympana ) and (iv) presence of black spots on the upper and lower lip (vs. uniform white lips in O. macrotympana ); (v) supernumerary tubercle indistinct (vs. supernumerary tubercle distinct in O. macrotympana ). Odorrana dulongensis sp. nov. differs from the enigmatic Odorrana sinica (Ahl 1927) by (i) granular dorsal skin (vs. smooth in O. sinica ); (ii) a distinct and uncovered tympanum (vs. an indistinct, skin-covered tympanum in O. sinica ), and a larger SVL in females (78.3–87.5 mm vs. 66.7 mm in O. sinica ).

Etymology. The specific epithet refers to the type locality, Dulongjiang village in Gongshan county, Nujiang Prefecture, Yunnan Province, China.

Distribution and ecology. Presently, Odorrana dulongensis sp. nov. is known only from the type locality in Dulongjiang village, Nujiang Prefecture, Yunnan Province, China ( Fig. 1 ). The collected individuals were encountered at night, sitting on branches along the Dulong River near a waterfall (Fig. 6). The Dulong River at this point was 30-50 m wide and surged. The banks of the river were covered by evergreen broad-leaf forests. Other frog species observed at the type locality included Zhangixalus burmanus (Andersson 1939) and Duttaphrynus cyphosus (Günther 1864) .

Figures

FIGURE 1. Type locality (red cycle) of Odorrana dulongensis sp. nov. in Dulongjiang, Gaoligongshan National Nature Reserve, Yunnan Province, China.

FIGURE 3. (A) Dorsolateral, dorsal (B), ventral (C) and head (D) views of Odorrana dulongensis sp. nov. (KIZ 035029) in life.

FIGURE 4. (A) Dorsal and (B) ventral views of the front feet, and (C) dorsal and (D) ventral views of the back feet of Odorrana dulongensis sp. nov. (KIZ 035029) in life.

FIGURE 5. (A) Habitat of Odorrana dulongensis sp. nov. near Dulong river in Gaoligongshan National Nature Reserve, Yunnan Province, China.