Sumaterana montana, Arifin, Umilaela, Smart, Utpal, Hertwig, Stefan T., Smith, Eric N., Iskandar, Djoko T. & Alexander Haas,, 2018

Arifin, Umilaela, Smart, Utpal, Hertwig, Stefan T., Smith, Eric N., Iskandar, Djoko T. & Alexander Haas,, 2018, Molecular phylogenetic analysis of a taxonomically unstable ranid from Sumatra, Indonesia, reveals a new genus with gastromyzophorous tadpoles and two new species, Zoosystematics and Evolution 94 (1), pp. 163-193 : 174-175

Sumaterana montana sp. n. Figs 2 Clade B, 5c, 6c

Holotype.

MZB.AMPH.29377 (female), Gunung Baru, Desa (=village) Seblat Ulu, Taman Nasional (=National Park) Kerinci-Seblat, Kabupaten Lebong, Provinsi Bengkulu, Sumatra, Indonesia (02.88413°S, 102.13073°E), 2033 m a.s.l., 4 May 2014, 20:44, coll. U. Arifin.

Paratypes (10).

ZMH.A14194 (female, Fig. 5c and Fig. 6c), approx. 300 m from the holotype locality (02.88525°S, 102.12993°E), 2000 m a.s.l., 3 May 2014, 22:04, coll. U. Arifin and G. Cahyadi. MZB.AMPH.23516 (male) and MZB.AMPH.23517 (female), 02.55397°N, 098.59806°E, 1774 m a.s.l.; MZB.AMPH.23518 (female), UTA.A64829 (female), MZB.AMPH.23519 (male), MZB.AMPH.23520 (male), UTA.A64830 (male), UTA.A64831 (male), UTA.A64832 (male), 2.54691°N, 98.61414°E, 1780 m a.s.l.; vicinity of Tele, Kecamatan Samosir, Kabupaten Toba-Samosir, Provinsi Sumatera Utara, Indonesia, 20 January 2014, coll. E. N. Smith, M. I. Lubis, K. A. O’Connell, and E. Wostl.

Referred specimens (16).

See Appendix 1.

Diagnosis.

(1) medium sized frog, SVL males (n = 10) 27.94-31.56 mm and females (n = 7) 50.11-63.37 mm; (2) dorsum skin finely granulated, color generally brown with scattered light spots; (3) tympanum distinct and translucent, slightly deep, supratympanic fold present, posttympanic fold absent; (4) dorsolateral fold present, thin, continuation of supratympanic fold to the level of pelvic joint, uninterrupted or broken; (5) venter smooth, white or yellowish; (6) tibia length 69.63-79.67% SVL; (7) Finger I 87.67-10.18% Finger II; (8) width of disc of Finger III 73.68-120.00% width of disc of Toe IV; (9) rear of thigh mottled; (10) approx. a quarter of the upper part of iris golden brown and the remaining iris with dense bright red stippling on black background; (11) webbing formula: I(0+―11/2)II(0+―2)III(0+―3+)IV(3-―0+)V; (12) outer metatarsal tubercle absent, inner metatarsal tubercle present; (13) males with paired vocal sacs, undivided nuptial pad, humeral gland absent.

Comparisons.

Sumaterana montana sp. n. differs from S. crassiovis comb. n. (character in parentheses) in these characters: dorsum color brown with scattered light blotches (green background with dark markings on tubercles, lighter area forming irregular network pattern); iris golden brown in the upper quadrant, below with dense bright red stippling on back background (golden yellow with reddish color in the anterior and posterior sector and dark netting pattern); rear of thigh mottled, light spots on dark background (usually with vertical dark bars on lighter background, as continuation of dorsal thigh); dorsal texture shagreened, generally without tubercles (finely granulated with scattered tubercles); length of Finger I ≈ Finger II (Finger I <Finger II); disc width of Finger III ≈ disc width of Toe IV (disc width of Finger III> disc width of Toe IV); dorsolateral fold present, thin (absent); webbing formula: I(0+―11/2)II(0-―2)III(0-―3+)IV(3-―0+)V (I(1+/-―1+/-)II(1+/-―1+/-)III(1+/-―2+/-)IV(2+/-―1+/-)V).

Description of holotype.

Adult female, gravid; body relatively slender; head width 91.93% head length; snout rounded, slightly pointed in dorsal view, and slightly protruding in lateral view; vomerine teeth present, in oblique groups, between choanae; loreal area deeply concave; canthus rostralis sharp, constricted behind nostrils; rictal ridge present; eye-nostril distance 133.41% of snout-nostril distance; interorbital distance 99.00% width of upper eyelid; tympanum distinct, translucent, slightly set deep, diameter <50% ED (TYv/ED = 49.31%, TYh/ED = 44.91%); supratympanic fold present, posttympanic fold absent; pineal spot visible; dorsolateral fold thin, starting in line with supratympanic fold anteriorly to the level of pelvic joint; dorsum and flank skin shagreened; venter skin smooth. Arm slender, lower arm length 19.44% SVL; hand length 32.81% SVL; fingers long, without webbing, tip extended into discs, diamond-like shaped, with circummarginal groove; length of Finger I 96.63% Finger II, Finger III longest; flaps present on the outer phalanges of all fingers; subarticular tubercles distinctive; disc width of Finger III 94.42% disc width of Toe IV. Hindlimbs long, articulation of the heels reach far beyond the tip of snout when limb aligned with body, relative length of femur, foot, and tibia to SVL: 61.01%, 69.63%, and 59.24%, respectively; toe lengths: I <II <III <V <IV, Toe V only slightly longer than Toe III; toe tip extended into diamond-shaped discs; cirmummarginal groove present; webbing formula: I(0+―11/2)II(0+―2)III(0+―3+)IV(3-―0+)V; subarticular tubercle distinct; inner metatarsal tubercle distinct, oval, 152.09% T4DW; outer metatarsal tubercle absent; tarsal fold absent.

Holotype coloration.

In life, dorsum and upper head brown with scattered light spots; dark dorsolateral line from eye to groin; flanks brown lighting up ventrad, with yellowish color in the posterior region, and many round dark spots; venter yellowish, dark markings on throat up to half of abdomen; golden brown color in at the upper quarter sector of iris, the remaining parts of iris with dense red stippling on black background; a series of dark spots encircled base of upper eye lid; dark brown line from eye to nostril (along canthus rostralis) towards snout tip, not connected to counterpart at tip of snout; dark brown area between eye and tympanum; tympanum pale brown with darker spot in the center; upper lip background brown, lighter posteriorly, with dark brown spots; lower lip brown with few light spots; arm with four dark cross-bars, from elbow to wrist; dorsal face of thigh and tibia brown, each with 6 dark bars; yellow spots on groin; rear of thigh mottled, whitish and yellow spots on brown background; ventral skin of thigh dusted brown on cream background, denser on both lateral side of posterior region; webbing color brown. Color in preservative similar to life coloration; dorsum brown and markings remain the same; yellowish color on flanks and venter changed into white; iris color became gray.

Holotype measurements (mm).

SVL 59.60, HL 23.35, HW 21.65, SL 9.14, SN 4.16, EN 5.55, IND 7.58, IOD 5.94, ED 7.95, UEW 6.00, TYv 3.92, TYh 3.57, ET 2.31, LAL 12.32, HAL 20.79, FE 38.66, TL 41.50, FL 37.54, IMTL 3.27, F1L 7.59, F2L 7.73, F3DW 2.03, T4DW 2.15.

Variation.

(1) dorsum color background: light pale brown to dark brown; (2) lighter spots on dorsum, none to dense; variable size; (3) dorsolateral fold: continuous or interrupted, variable thickness; (4) yellowish posterior of flank; pale to brighter; (5) tubercles on flanks: none to many; (6) round dark spots on flanks, few to many; size: small to big; (7) dark marking on throat, chest, and ventrum: none to present and reaching the belly; (8) cross bars on limbs, 3-4 (arm, from elbow to wrist), 5-6 (thigh); variable thickness; (9) mottled pattern on rear of thigh: small, yellow and creamy spots to blotches, on brown background. (Metrics: Tables 4-5).

Sexual dimorphism.

Males smaller than females. Tympanum diameter 52.31-92.89% ED in males and 41.54-60.47% ED in females. Adult males with single, undivided nuptial pad covering base of the first finger to subarticular tubercle on dorsal and medial surface. Paired subgular vocal sacs visible, humeral glands absent.

Etymology.

The specific epithet is the Latin adjective montana in allusion to the distribution of this species at high elevations of the Bukit Barisan mountain range of Sumatra.

Common name.

We propose Mountain Cascade Frogs as common English name and Katak Jeram Gunung in Bahasa Indonesia.

Distribution and natural history.

Only known from high elevations of northern (Provinsi Aceh and Provinsi Sumatera Utara) and mid (Provinsi Bengkulu) Sumatra (Fig. 9). Known elevation was from 1190-2033 m a.s.l.. The holotype was perching on moss on a root of a dead tree, about 120 cm above a small creek (50 cm wide), ~50 m from Camp 4.5 of Gunung Baru, Desa Ulu Seblat, Taman Nasional Kerinci-Seblat, Kabupaten Lebong, Provinsi Bengkulu (~2000 m a.s.l.). The paratype ZMH.A14194 was observed sitting on the branch, about 300 m away, at the same creek where the holotype was collected, 200 cm above the ground. Accompanying fauna included species of Rhacophorus and Philautus . Paratypes from the vicinity of Tele, Kecamatan Samosir, Kabupaten Toba-Samosir, Provinsi Sumatera Utara were collected along the stream in the rainforest with patches of coffee plantation. The two specimens of Sumaterana montana sp. n. from the stream at Marpunge, Taman Nasional Gunung Leuser, Kabupaten Gayo Lues, Provinsi Aceh were found within low vegetation in the middle of the stream, S. crassiovis were abundant syntopically. Specimens from Gunung Sibuatan, Kabupaten Karo, Provinsi Sumatera Utara were found on the stream bank about 1-4 m away from water.

Tadpoles.

Unknown.