Rhacophorus napoensis, Li & Liu & Yu & Sun, 2022

Li, Jing, Liu, Shuo, Yu, Guohua & Sun, Tao, 2022, A new species of Rhacophorus (Anura, Rhacophoridae) from Guangxi, China, ZooKeys 1117, pp. 123-138 : 123

Rhacophorus napoensis sp. nov.

Figs 4 , 5 , 6

Material examined.

Holotype. GXNU YU000172 , adult male, collected on 25 March 2019 by Shuo Liu from Napo County, Baise City , Guangxi Zhuang Autonomous Region, China (23°1'20"N, 105°50'58"E, ca 1032 m a.s.l.) . Paratypes. GXNU YU000169 , GXNU YU000170 , GXNU YU000171 and GXNU YU000173 , four adult males, collected at the same time as the holotype from the type locality by Shuo Liu .

Etymology.

The specific epithet is named for the type locality. We suggest the English common name as "Napo tree frog" and the Chinese common name as “那坡树蛙”.

Diagnosis.

Morphologically, there are the following differences between Napo County specimens and other species belonging to Rhacophorus : (1) Medium body size (adult males SVL 38.6-43.6 mm); (2) snout pointed, projecting beyond margin of lower jaw in ventral view, and the tip has a distinct bulge; (3) tympanum distinct, rounded; (4) maxillary teeth distinct; (5) tongue cordiform, notably notched posteriorly; (6) external single subgular vocal sac; (7) the tibiotarsal articulation reaches the snout; (8) TIL longer than FL and slightly longer than half of SVL; (9) entire web between fingers and toes; (10) single inner metatarsal tubercle, flat; (11) banding exists in dorsal surface of limbs posterior part of dorsum; (12) two to three black spots at axillary region; (13) web is not black; and (14) dorsal color hoary with numerous black spots when the species is kept in preservative.

Description of holotype.

Adult male, body size medium (SVL 38.6 mm); head width (HW 15.0 mm) longer than head length (HL 14.7 mm); snout pointed, longer than diameter of eye (ED 5.8 mm), protruding from the margin of the lower jaw; canthus rostralis distinct; loreal region oblique; nostril small, closer to eye than to tip of snout; internasal space (INS 4.9 mm) longer than interorbital space (IOS 4.2 mm) and width of upper eyelid (UEW 4.3 mm); interorbital space (IOS 4.2 mm) almost equal to width of upper eyelid (UEW 4.3 mm); pineal ocellus absent; pupil horizontal; tympanum distinct, rounded, diameter of tympanum (TD 3.4 mm) longer than half eye diameter (ED 5.8 mm), internasal space (INS 4.9 mm) and half interorbital space (IOS 4.2 mm); supratympanic fold distinct; vomerine teeth present; maxillary teeth distinct; tongue cordiform, attached anteriorly, notably notched posteriorly; choanae oval; external single subgular vocal sac, vocal sac opening at the bottom of the mouth on either side.

Forelimbs stubby, length of lower arm and hand (LAHL 18.2 mm) shorter than snout-vent length (SVL 38.6 mm); fingers short, relative length of fingers: I <II <IV <III; tips of all fingers expanded into discs; entire web between fingers; subarticular tubercles prominent and rounded, formula 1, 1, 2, 2; supernumerary tubercles below the base of finger absent; single thenar (inner metacarpal) tubercle large, oval, distinct (Fig. 5a ).

Hindlimbs long and thin, tibia length (TIL 19.6 mm) longer than thigh length (THL 18.8 mm) and foot length (FL 17.6 mm), tibiotarsal articulation reaches the snout; when the legs are at right angles to the body, the heels overlap; relative length of toes is I <II <III <V <IV; tips of all toes expanded into discs; entire web between toes; subarticular tubercles prominent and rounded, formula 1, 1, 2, 3, 2; supernumerary tubercle below the base of toe absent; single inner metatarsal tubercle, flat (Fig. 5b ).

The skin of throat, ventral part of tibia, foot and tarsus smooth; the skin of chest, venter, vent and thigh rough and granular; some warts are found around the vent and flanks; dermal fringe along joint, vent and the outer sides of limbs (Fig. 4b ); three black spots at the right armpit (Fig. 6a ), and two black spots at the left armpit (Fig. 6b ).

Color of holotype in preservative. Dorsal color hoary with numerous black spots; horizontal banding on dorsum and dorsal surface of limbs (Fig. 4a ).

Male secondary sexual characteristics. No nuptial pad and lineae masculinae were observed.

Morphological variation.

The morphological measurement and the number of dark spots at axillary region of the holotype and paratypes are shown in Table 2 . The total number of dark spots at axillary region varies between individuals, and the number of dark spots on the left and right axillary region also varies. Because all specimens are male, sexual dimorphism cannot be determined.

Distribution and ecology.

The new species was found near several large rocks in the bushes, 306 m southeast of Nongyao, Napo County, Baise City, Guangxi Zhuang Autonomous Region, China (Fig. 7 ). Vocal recordings and tadpoles of this new species were not collected.

Comparisons.

The new species is obviously distinguishable from most of the closely-related species including R. norhayatii , R. reinwardtii , R. kio , R. borneensis , and R. helenae by smaller body size (SVL of adult males 38.6-43.6 mm vs. 64.7 mm in R. norhayatii , 41.1-52.5 mm in R. reinwardtii , 70.5 mm in R. kio , 50.9 mm in R. borneensis , and 72.3-85.5 mm in R. helenae ) and lack of black coloration on the webs (vs. webs between toes black).

The new species differs from R. rhodopus by head width greater than head length (vs. head length almost equal to head width), snout pointed and the tip has a distinct bulge (vs. snout oblique and pointed) (Fig. 4 ), tongue cordiform, notably notched posteriorly (vs. tongue narrow and long, deeply notched posteriorly), external single subgular vocal sac (vs. internal single subgular vocal sac), the tibiotarsal articulation reaches the snout (vs. the tibiotarsal articulation reaches the eye), tibia length is slightly greater than half of snout-vent length (vs. tibia length is about half of snout-vent length), two to three black spots at axillary region (vs. one black or dark round spot at axillary region); and from R. bipunctatus by head width greater than head length (vs. head length almost equal to head width), snout pointed, and the tip has a distinct bulge (vs. snout broad and pointed), loreal region oblique (vs. loreal region concave), tympanum distinct (vs. tympanum indistinct), maxillary teeth distinct (vs. tooth-like projection on maxilla absent), tongue cordiform, notably notched posteriorly (vs. tongue medium size, round, slight notched posteriorly, median lingual process absent), slender toes (vs. toes rather short, thin), tibia length is slightly greater than half of snout-vent length (vs. tibia length is slightly less than half of snout-vent length), two to three black spots at axillary region (vs. one big and one small black spot at axillary region).

Figures

Figure 4. Dorsal views (a) and ventral views (b) of the holotype of R. napoensis sp. nov. (GXNU YU 000172) in preservative. Ventral view (c) of R. rhodopus from type locality (090142) in preservative.

Figure 5. Ventral view of hand (a) and foot (b) of the holotype of R. napoensis sp. nov. (GXNU YU 000172) in preservative.

Figure 6. Right armpit and flank view (a) and the left armpit and flank view (b) of the holotype of R. napoensis sp. nov. (GXNU YU 000172) in preservative.

Figure 7. Habitat of R. napoensis sp. nov. at the type locality.