Rana iriodes, BAIN & TRUONG, 2004

BAIN, RAOUL H. & TRUONG, NGUYEN QUANG, 2004, Herpetofaunal Diversity of Ha Giang Province in Northeastern Vietnam, with Descriptions of Two New Species, American Museum Novitates 3453, pp. 1-43 : 12-17

Rana iriodes , new species

Figures 6A, B , 7–9

HOLOTYPE: AMNH 163925/IEBR 70 (AMNH Field Series 15556), a mature male from Mt. Tay Con Linh II, Cao Bo Commune, Vi Xuyen District, Ha Giang Province, Vietnam (site 2: 22°46̍10̎N, 104°49̍53̎E, elevation 1400 m) found on 10 May 2000 by Q.T. Nguyen and R.H. Bain. The holotype was on a wet, mossy rock near a stream. The holotype had leg muscle and liver removed shortly after it was euthanised.

PARATYPES: One mature male (AMNH 163928) and one gravid female (AMNH 163926) collected with holotype on 10 May 2000 by Q.T. Nguyen and R.H. Bain. Specimens were collected along mossy rocks and small branches overhanging a stream. Mature male (AMNH 163924/IEBR 69) collected from Mt. Tay Con Linh II, Cao Bo Commune, Vi Xuyen District, Ha Giang Province, Vietnam (ca. 1 km south–southwest of 22°45̍27̎N, 104°49̍35̎E, 1700 m) on 19 May 2000 by P.R. Sweet and R.H. Bain. This specimen was found at small, rocky­bottomed forest pools, about 10 m from the nearest stream .

DIAGNOSIS: Rana iriodes is characterized by a combination of the following characters: SVL of males 39–43 mm (mean 40.32 mm), female 62; vomerine teeth loosely grouped along crescent­shaped ridge between choanae; golden lip stripe extends to form rough line across flank; dorsum iridescent green or green­gold; dorsolateral folds weak, iridescent gold or orange­red; flanks with white glandular spot; no lateral furrows on fingers; web full to toe disks on toes I, V, and postaxial sides of II and III, reaching disks as a fringe on all other toes; no external metatarsal tubercle; males with paired gular pouches, nuptial spines absent; eggs not pigment­ ed.

DESCRIPTION OF HOLOTYPE: AMNH 163925/ IEBR 70, a mature male, SVL 39.40 mm, HDW:HDL 0.94, HDL:SVL 0.34; pupil broadly oval; snout short, rounded in dorsal view, broadly rounded in profile, protruding beyond margin of lower jaw; eye prominent, EYE:SNT 0.57; eyelid broader than interorbital distance. Top of head flat; canthus rostralis rounded; loreal region concave; lip flared just anterior to orbit; nostril about three­fourths distance from eye to tip of snout; weak supratympanic fold curving posteroventrally from posterior corner of eye to level above insertion of arm; tympanum round, distinctly visible, separated from eye by distance less than tympanum diameter, TMP:EYE 0.68; choanae ovoid; vomerine dentigerous processes weakly developed medially along crescent­shaped ridge between choanae, a few loosely grouped teeth; tongue cordiform, distinctly notched posteriorly, free for approximately two­thirds its length.

Forearms robust; fingers moderately short, slender, HND:SVL 0.32, relative lengths of fingers I ‹ II ‹ IV ‹ III, median callous pads to proximal tubercle on fingers II, III, IV, no lateral furrows on edges of fingers; disks on tips of fingers greatly expanded (›2× base of phalange), relative pad size I ‹ II ‹ IV ‹ III, pad width of finger III greater than TMP, ventral circummarginal grooves present; terminal phalanges T­shaped; subarticular tubercles conical. Hindlimbs moderately robust; TIB:SVL 0.65; FTL:SVL 0.88; relative toe lengths I ‹ II ‹ II = V ‹ IV; inner tarsal fold absent; web full to base of toe disk on toes I, V, and postaxial sides of II and III, reaches disks as a fringe on all other toes: web full to beyond subarticular tubercle on preaxial side of II, and to level of distal subarticular tubercle of IV and preaxial side of III, lateral fringes on preaxial side of I and postaxial side of V to terminal phalanges; toes long, slender, with large, rounded triangular disks (›2× base of phalange), pad size of all toes equal to each other, smaller than those of fingers, with ventral circummarginal grooves; subarticular tubercles prominent and conical; inner metatarsal tubercle ovoid, long; outer metatarsal tubercle absent.

Skin on dorsum, sides, venter, and around anus smooth; dorsolateral folds weak; anus unmodified, directed posteriorly, at upper level of thighs.

COLOR IN LIFE (in preservative): Dorsum iridescent light green (livid blue) with some black spots; green loreal spot (livid blue); black stripe (dark gray), from loreal region across tympanum to insertion of arm, continues as thin line below dorsolateral folds; gold lip stripe (white) extends beyond tympanum to form rough line across flank; tympanum dark brown; iris gold for ventral two­thirds, dorsal one­third red with some gold flecks; iridescent orange­red dorsolateral stripe (thin, gray); flanks iridescent gold­green with some brown and yellow marbling (gray, white), two gold­white spots on left posterior flank, one on right (white); dorsal limbs tan (light brown) with dark brown transverse bars (dark brown); posterior surface of thighs yellow with black marbling (brown); webbing marbled white on dark brown (gray on brown); venter with iridescent gold­white irregular spots (off­white with irregular gray spots on throat and chest, legs creamy yellow with light brown mottling toward knees).

MALE SECONDARY SEX CHARACTERS: Holotype with greatly enlarged forearms and paired gular pouches; a white, velvety nuptial pad along base of finger I; nuptial spines absent.

MEASUREMENTS OF HOLOTYPE (in mm) (AMNH 163925/IEBR70): SVL 39.40, SNT 5.15, HDL 13.53, HDW 12.72, EYE 2.96, IOD 4.03, TMP 1.86, HND 12.85, TIB 25.59, FTL 34.76.

VARIATION OF PARATYPES: Rana iriodes exhibits sexual dimorphism: females are larger than males, SVL 61.88 mm (mean of male paratypes 41.0 mm [38.80, 43.24 mm]); females with smaller TMP:EYE (female 0.35, mean paratype males 0.54 [0.57, 0.51]); females with larger EYE:SNT (female 0.94, mean paratype males 0.67 [0.68, 0.66]); females with smaller FTL:SVL (female 0.69, mean paratype males 0.86 [0.90, 0.82]). Females have unpigmented eggs. The xiphisternum of females is large and deeply notched posteriorly. Some specimens with iridescent light green­gold on the dorsum (livid blue in preservative). The dorsolateral stripe sometimes appears as iridescent gold (thin, gray stripe in preservative). AMNH 163928 (male) has red­brown arms with irregular brown transverse bars and some gold patches above the eye; other specimens with green or gold flecks on limbs, with more gold extending to ventral thighs (dark brown bars on light brown limbs in preservative). In preservative, ventral mottling varies from absent to gray on throat and chest. All paratypes only have one glandular gold­white spot on each flank.

MEASUREMENTS OF MALE PARATYPES (in mm, AMNH 163924, 163928): SVL 38.80, 43.24; SNT 5.40, 5.79; HDL 15.07, 13.95; HDW 13.51, 14.10; EYE 3.70, 3.83; IOD 4.26, 4.37; TMP 2.14, 1.96; HND 13.87, 12.70; TIB 26.52, 25.40; FTL 34.89, 35.35; HDL:HDW 1.11, 0.98, TIB:SVL 0.68, 0.59, SNT:HDL 0.36, 0.42.

MEASUREMENTS OF FEMALE PARATYPE (in mm, AMNH 163926): SVL 61.88, SNT 8.15, HDL 22.10, HDW 20.29, EYE 7.70, IOD 5.42, TMP 2.72, HND 19.29, FPL 2.62, TIB 36.72, FTL 42.90.

COMPARISONS: Rana iriodes superficially resembles other Asian cascade ranids, but can be differentiated from them by its gold or orange­red dorsolateral folds and glandular gold­white flank spot: R. andersonii , R. bacboensis , R. chloronota , R. hainanensis , R. hejiangensis , R. jingdongensis , R. junlianensis , R. kwangwuensis , R. livida , R. margaretae , R. morafkai , R. schmackeri , R. sinica , and R. tiannanensis (dorsolateral folds and flank spots absent); Amolops chunganensis , R. banaorum , R. chalconota , R. exiliversabilis , R. graminea , R. hosii , R. leporipes , R. nasuta , R. trankieni , and R. versabilis (dorsolateral folds present, but none with gold or orange­red; flank spots absent); Huia nasica , R. archotaphus , R. grahami , R. hmongorum , and R. megatympanum (dorsolateral fold present or absent, never gold or orange­red; flank spots absent); R. daorum (white glandular dorsolateral folds, glandular white flank spot). The absence of a furrow on the medial edge of fingers II and III differentiates R. iriodes from other cascade ranids in which this character has been noted: R. archotaphus , R. bacboensis , R. banaorum , R. chalconota , R. chloronota , R. daorum , R. graminea , R. hmongorum , R. hosii , R. livida , R.morafkai , R. megatympanum , and R. trankieni (absent in Amolops chunganensis and Huia nasica ; undescribed in other cascade ranids).

Rana iriodes most closely resembles R. daorum and A. chunganensis . It can further be differentiated from R. daorum by its vomerine teeth (absent in R. daorum ), size ( R. daorum male SVL 32–38, R. iriodes 39–43 mm), and male TMP:EYE (0.18–0.38 for R. daorum , 0.47–0.75 for R. iriodes ). It can further be differentiated from Amolops chunganensis by its color ( A. chunganensis redbrown, R. iriodes iridescent light green with black spots), lip stripe (white in A. chunganensis , yellow in R. iriodes ), webbing on toe IV (reaches just beyond distal subarticular tubercle in A. chunganensis ; full to distal subarticular tubercle, then to the disk as fringe for R. iriodes ).

Character states for the condition of finger furrows was obtained by direct observation of specimens (appendix 1) and from the original description of R. trankieni (Orlov et al., 2003) . All other character information on R. exiliversabilis and R. nasuta is from Fei et al. (2001), on R. trankieni from Orlov et al. (2003), and R. versabilis from Liu and Hu (1962). Refer to table 3 and Bain et al. (2003: table 12) for detailed comparisons of regional cascade ranids.

ETYMOLOGY: The specific name is from the Latin iriodes , meaning iridescent. This refers to the iridescent nature of the skin in life.

DISTRIBUTION: This species is currently known only from Mt. Tay Con Linh II in northeastern Vietnam: Ha Giang Province, Vi Xuyen District, Cao Bo Commune.

REMARKS: Neither tadpoles nor vocal recordings were collected for this species. Male specimens exhibit gular pouches that are either loose and baggy (distended) or tight, appearing as folds of skin at the corner of the jaw.

Figures

Fig. 6. Three frog species from Ha Giang Province, Vietnam: (A) paratype of Rana iriodes, new species (AMNH 163928), adult male, SVL 42.80 mm; (B) paratype of Rana iriodes, new species; (C) paratype of Rana tabaca, new species (AMNH 163915), adult male, SVL 59.18 mm; (D) paratype of Rana tabaca, new species (AMNH 163920), adult female, SVL 103.40 mm; (E) Polypedates dugritei (AMNH 163910), adult male, in profile; and (F) posterior view showing transmedial white line, SVL 40.50 mm.

Fig. 7. Holotype of Rana iriodes, new species (AMNH 163925/IEBR 70), adult male from Mt. Tay Con Linh II: dorsal view (left), ventral view (right). Scales equal 10 mm.

Fig. 8. Head of Rana iriodes, new species (AMNH 163925/IEBR 70), holotype in profile. Scale equals 2.5 mm.

Fig. 9. Hand (left) and foot (right) of Rana iriodes, new species (AMNH 163925/IEBR 70), holotype. Scales equal 5 mm.