Amolops nepalicus Yang, 1991

Wang, Kai, Bhattarai, Santosh, Wu, Yunhe, Che, Jing & Siler, Cameron D., 2020, Resurrection of Amolops nepalicus Yang, 1991 (Amphibia: Anura: Ranidae), with Comments on the Record of A. cf. afghanus in Nepal and China and the Validity of Two Other Junior Synonyms of A. marmoratus (Blyth, 1855), Zootaxa 4819 (1), pp. 143-158 : 147-149

Amolops nepalicus Yang, 1991

( Table 1, Figs. 3 , 4 )

Chresonymy. Staurois himalayana (original collecting information by Douglas Lay, 1973)

Amolops marmoratus Dubois, 2000

Holotype. UMMZ 132063 , adult male, collected 2km East of Barabise (=Barahabise), which is on Sabhaya Khola (=Sabha Khola), Sankhuwasabha District, eastern Nepal, elevation 2200ft (about 670m). Collected by Douglas Lay in May 1973.

Comment on the type locality. In the original description, Yang (1991) wrote “Sabhya Kbota, Nepal ”. However, upon exemption of the original museum record, the full locality information of the holotype is much more detailed: “ Nepal: Barabise, 2200ft (Barabise is on Sabhya Khola, tributary of Arun River, ca. 3km NE of Khanbari).” According to the original record, the type locality is roughly at 27°25'34"N, 87°18'23"E, WGS 84 .

Diagnosis. A small sized frog that can be diagnosed by a combination of the following characters: (1) body size small, SVL 37.8mm in adult male; (2) head relatively narrow, longer than wide, HW 86.2% HL in male; (3) nostril about midway between eyes and snout, END 106.0% SND; (4) Finger I longer than Finger II, FLI 127.2% FL2; (5) Finger I with distal disc, well developed, FDW1 60.8% FDW3, with transverse and circummarginal grooves; (6) tibia length equal to femur length, TIB 100.1% FEM; (7) both inner and outer metatarsal tubercles present, inner tubercle elongated, outer tubercle smaller; (8) background skin of dorsal surface of body rough but fine, with distinct larger tubercles scattered evenly; (9) lateral surface of body more granular, also with enlarged tubercles; (10) well developed glands present in incomplete series along dorsolateral junction of body on each side; (11) supratympanic fold distinct but thin, extending from eye to region posterior to shoulder joint, continuous with dorsolateral series of glands on dorsum; (12) tympanum distinct, annulus raised; (13) dual vocal sacs and vocal apertures present in male; (14) nuptial pads present on Finger I of male, without nuptial spines; (15) fingers free from webbing, toes fully webbed, weakly notched, webbing formula I0-0II0-0III0-0IV0-0V.

Redescription of holotype. Adult male, small in size, SVL 37.8mm. Head narrow, longer than wide, HW 86.2% HL; snout pointy, projecting slightly over lower jaw, SNL 36.8% HL; nostril oval, located about midway between snout tip and eyes, END 106.0% SND; canthus rostralis distinct, loreal region slightly concave; upper lips convex; eyes large, ED 130.7% IND; dorsal surface of head mostly smooth, with few enlarged, raised tubercles posterior to eyes; single rictal gland at corner of mouth on each side of head, bean shaped; tympanum distinct, with raised annulus, TMD 40.5% ED; supratympanic fold distinct, thin, covering the superior and posterosuperior sides of tympanum and connecting to dorsolateral series of glands. Vomerine teeth distinct, in two oblique rows, forming “\ /” shape; vocal aperture and dual vocal sacs present.

Background dorsal skin finely granular, with numerous enlarged, flat tubercles scattered evenly; dorsolateral glands forming incomplete series on each side of dorsum, in contact with supratympanic fold anteriorly and extending posteriorly toward pelvis; lateral skin of body granular, also with enlarged tubercles scattered. Ventral surfaces of head and body smooth; granular on posteroventral region of thigh and near cloaca.

Dorsal surfaces of limbs rough, with many small to medium tubercles, many tubercles forming longitudinal ridges on crus and thigh. Fingers long, slender, free of webbing, all with expanded discs, transverse grooves, and circummarginal grooves, FDW1 60.8% FDW3; Finger I longer than Finger II, FL1 127.2% FL2, relative finger lengths III>IV>I>II; enlarged nuptial pad present on Finger I, extending from base to distal end of subarticular tubercle, covering dorsal and posterior sides of finger; subarticular tubercles oval, distinct, I (1), II (1), III (2), IV (2); single supernumerary tubercle present on each finger except Finger I; inner and outer metacarpal tubercles large, elevated, fused medially. Toes long, fully webbed, webbing formula I0-0II0-0III0-0IV0-0V, all with enlarged discs, transverse grooves, and circummarginal grooves, TDW4 82.4% FDW3; relative toe lengths IV> V> III> II> I; subarticular tubercles oval, smaller than those on fingers, I (1), II (1), III (2), IV (3), V (2); both inner and outer metatarsal tubercles present, inner tubercle elongated and larger, about three-times size of outer.

Coloration. After long-term preservation, the background coloration of the dorsal surfaces of the head and body is from Vinaceous Pink (Color 245) to pale Deep Vinaceous (Color 248). Irregularly shaped, Beige (Color 254) speckles are present and scattered on the top of the head and dorsal body surfaces. The enlarged flat tubercles of the posterior region on top of thel head and dorsum, the supratympanic folds, and the dorsolateral series of glands of the dorsum are darker Burnt Sienna (Color 38). The lateral surfaces of the head and body are Pale Pinkish Buff (Color 3), with fine, Deep Vinaceous (Color 248) speckles. The dorsal surfaces of the fore-limbs are mostly uniform pale Deep Vinaceous (Color 248); and hind limb surfaces are more distinctively patterned, with Mahogany Red (Color 34), marbled transverse patches, which are more distinct and saturated on the posterolateral regions of the thigh and crus. The ventral surfaces of the head, body, and limbs are uniform Buff (Color 5).

Comparisons. Amolops nepalicus was considered as a junior synonym of A. marmoratus , and it is similar to A. marmoratus in having a small body size, enlarged tubercles on the dorsum, and by the presence of dual vocal sacs in adult males. However, A. nepalicus differs from A. marmoratus by having a relatively narrower head (HW 86.2% HL in male vs. 91.5–96.4% in males; One Sample T-Test p=0.0002), and a different nostril position (about midway between eye and nostril, END 106.0% SND vs. closer to snout, 118.8–125.0% in males; One Sample T-test, p=0.0001) ( Fig. 4 ).

For the remaining species of the A. marmoratus complex, A. nepalicus differs from A. afghanus by having a smaller body size (37.8mm vs. 43.5–67.1mm in males), oblique orientation of vomerine teeth (vs. mostly transverse), and by the presence of distinct, enlarged tubercles on the dorsum (vs. absence or presence but small and indistinct); from A. assamensis by having a smaller body size (37.8mm in male vs. ≥ 52.8mm in males) and a narrower head (HW 86.2 % HL vs.>100.0%); from A. indoburmanensis by having a smaller body size (37.8mm in male vs. 63.1–77.5mm in males), a relatively narrower head (HW 86.2 % HL in male vs. 94.0–99.7% in males), and by the presence of distinct, enlarged tubercles on the dorsal and lateral surfaces of the body (vs. absence); from A. panhai by the absence of axillary glands (vs. presence).

Compared to species of the A. ricketti group and A. daiyunensis group, A. nepalicus differs from A. albispinus , A. hongkongensis , A. ricketti , A. sinensis , A. wuyiensis , A. yatseni , and A. yunkaiensis by the absence (vs. presence) of nuptial spines on Finger I in males and by the presence of outer metatarsal tubercle (vs. absence); and from A. daiyunensis by the presence of distinct vomerine teeth (vs. absence). Compared to the A. hainanensis group, A. nepalicus differs from A. hainanensis and A. torrentis by the presence of vomerine teeth (vs. absence).

Amolops nepalicus differs from all members of the A. monticola group ( A. aniqiaoensis , A. archotaphus , A. akhaorum , A. bellulus , A. chakrataensis , A. chayuensis , A. chunganensis , A. compotrix , A. cucae , A. daorum , A. granulosus , A. iriodes , A. kohimaensis , A. mengdingensis , A. mengyangensis , A. monticola , A. minutus , A. nyingchiensis , A. tuanjieensis , A. vitreus , and A. wenshanensis ) by the absence of true dorsolateral folds (vs. presence), presence of enlarged tubercles on the dorsal and lateral surfaces of the body (vs. absence), and presence of outer metatarsal tubercles (vs. absence); from all members of the A. mantzorum group ( A. granulosa , A. jingjiangensis , A. loloensis , A. lifanensis , A. mantzorum , A. ottorum , A. shuichengensis , A. tuberodepressus , and A. xinduqiao ) by the presence of circummarginal grooves on Finger I (vs. absence); from A. viridimaculatus group ( A. viridimaculatus ) by the presence of gular sacs in males and presence of outer metatarsal tubercle (vs. absence).

For the remaining species of Amolops recognized to occur in the Pan-Himalayas and Southeast Asia, A. nepalicus differs from A. formosus , A. himalayanus , A. pallasitatus , and A. splendissimus by the presence of outer metatar- sal tubercle (vs. absence), presence of a circummarginal groove on Finger I (vs. absence), and presence of distinct, enlarged tubercles on the dorsal surface of the body (vs. absence); from A. cremnobatus and A. kaulbacki by the presence of vocal sacs in males (vs. absence); from A. nidorbellus by have a smaller body size (37.8mm in male vs. ≥ 76.4mm in males) and narrower head (HW 86.2% HL vs.>100.0%); from A. gerbillus by having large and distinct tympana (TMD 40.5% ED vs. about one-third, small and indistinct; Annandale 1912) and by the presence of outer metatarsal tubercles (vs. absence); from A. caelumnoctis and A. medogensis by the presence of enlarged tubercles on the dorsal and lateral surfaces of the body (vs. absence) and presence of vocal sacs in males (vs. absence); from A. jaunsari by having a narrower head (HW 86.2% HL vs. “as long as broad”; Ray 1999); from A. longimanus by having larger tympanum (TMD 40.5% ED vs. about one quarter; Andersson 1939) and by the presence of outer metatarsal tubercle (vs. absence); from A. spinapectoralis by the presence of outer metatarsal tubercle (vs. absence) and by the absence of conical spines on nuptial pads (vs. presence); and from A. larutensis , A. gerutu , and A. australis by the absence of axillary glands (vs. presence).

Figures

FIGURE 3. Photographs of the holotype of A. nepalicus UMMZ 132063 showing (A) dorsal view, (B) ventral view, (C) dorsolateral closeup of dorsum, (D) dorsal close-up of head and dorsum, (E) lateral close-up of head, (F) ventral closeup of head, (G) ventral close up of left hand, and (H) ventral close up of left foot. Individual images are not to scale. Photographs by Kai Wang.

FIGURE 4. Comparisons between males of (A) Amolops nepalicus UMMZ 132063, (B) A. marmoratus CAS 240545, and (C) A. afghanus CAS 220182, as well as a female of (D) A. cf. afghanus from Nepal CAS 145816, and a juvenile of (E) A. cf. afghanus from China CAS 177645. Different columns show (1) skin texture on the dorsolateral surfaces of the body, (2) head shape, (3) other characters on the lateral head (i.e. nostril position and distinctiveness of tympanum and supratympanic fold), (4) gular pouch/vocal sacs, (5) relative finger length and shape and size of nuptial pads when applicable, and (6) webbing formula and subdigital tubercles of the foot (6). Individual images are not to scale. Photographs by Kai Wang.