Sigalegalephrnnus minangkabauensis, Smart & Sarker & Arifin & Harvey & Sidik & Hamidy & Kurniawan & Smith, 2017

Smart, Utpal, Sarker, Goutam C., Arifin, Umilaela, Harvey, Michael B., Sidik, Irvan, Hamidy, Amir, Kurniawan, Nia & Smith, Eric N., 2017, A New Genus and Two New Species of Arboreal Toads from the Highlands of Sumatra with a Phylogeny of Sundaland Toad Genera, Herpetologica 73 (1), pp. 63-75 : 63-75

Sigalegalephrŋnus minangkabauensis sp. nov.

Holotype. — Museum Zoologicum Bogoriense Amphibian Collection , MZB 25738 (field number ENS 16028 ), an adult male ( Fig. 7 ) from Gunung Kunyit , Kecamatan Panyabungan Selatan , Kabupaten Kerinci, Provinsi Jambi, Indonesia, 2.26013°S, 101.49512°E at 1402 m, collected by E. Wostl, E.N. Smith, W. Trilaksono, and G. Barraza on 24 June 2013.

Diagnosis and comparison. —The following combination of characters is unique to Sigalegalephrŋnus minangkabauensis : (1) A small (19.32 mm SVL) and slender toad without parotoid glands. (2) Fingertips I and II are rounded and not expanded. (3) Fingertips III and IV are rounded and expanded. (4) The toe tips are rounded but not expanded. (5) The webbing is rudimentary in the hands and moderate in the feet. (6) The dorsum is light greenish-brown with a middorsal pinstripe extending from the tip of the snout to the vent. (7) The flanks have a single stroke of dark brown extending from the posterior end of the orbit to the inguinal region. (8) The dorsal surface is moderately tuberculate. (9) The ventral surface is smooth with scattered black spots.

Sigalegalephrŋnus minangkabauensis can be distinguished from S. mandailinguensis (characters in parentheses) based on the following differences. The tympanum is barely discernible (tympanum distinct). The finger-pads are moderately defined (finger-pads prominent). The fingertips are rounded but not expanded (distinctly spatulate on tips III to IV). The hands lack subarticular tubercles (distinct subarticular tubercles under Fingers III and IV). The webbing of the foot is more extensive, extending to the last phalanx on Toes I and II (last phalanx free of webbing). The pads on toes are moderately defined (pads prominent). The feet lack subarticular tubercles (distinct subarticular tubercles under Toes IV and V). The overall texture is glossy with fewer tubercles on the dorsum and flanks (overall texture rugose, body and flanks extensively tuberculate). Taking into account the uncorrected genetic distance between the two species of Sigalegalephrŋnus ( Table 2 ), the aforementioned comparisons provide adequate diagnostic characters to warrant S. minangkabauensis as a species distinct from S. mandailinguensis .

Description of holotype. —The holotype (sex indistinguishable) has SVL of 19.32 mm; head length 6.94 mm; head width 6.57 mm; snout length 2.7 mm; eye length 2.2 mm; eye–nares length 1.6 mm; distance between nares to tip of snout 0.6 mm; internarial distance 1.8 mm; intercanthal distance 3.6 mm; forearm length 6.0 mm; hand length 5.5 mm; femur length 8.5 mm; tibia length 8.71 mm; tarsal length 5.1 mm; foot length 7.5 mm; width of fingertip pad of Finger III 1.6 mm; Finger IV 1.4 mm.

Body slender, head little longer than wide; head length 36.1% SVL, head width 34.0% SVL; snout length 14% SVL; canthus rostralis concave; loreal area without tubercules and concave; snout truncated and slightly sloping back toward mouth; snout mucronate and with prominent median keel in dorsal view; eye length 11.4% SVL; pupil horizontal; upper eyelid granular; tympanum barely visible, with no supratympanic fold; interorbital space flat; cranial crests absent; no teeth in jaws; tongue tip oval-shaped, longer than wide; skin of dorsal surfaces rough to finely shagreen with few large, scattered tubercles; tubercles small, rounded, and almost without keratinization; no dorsolateral, paravertebral, or occipital folds; skin on venter smooth with few fine warts; forearm length 31.1% SVL; hand length 28.5% SVL; relative lengths of Fingers I <II <IV <III; fingers bearing expanded pads; webbing of hands moderate: between Fingers I and II reaches distal and proximal subarticular tubercles, respectively; between Fingers II and III reaches proximal subarticular tubercles; between Fingers III and IV reaches proximal subarticular tubercles; webbing formula for the hand I1 1 / 2 –2II2–2 2 / 3 III2 2 / 3 –2IV; elongate inner metacarpal tubercle below Finger I as large as outer metarcarpal tubercle; lower arm with indistinct tubercles; fingers without expanded pads; femur length 44.0% SVL; tibia length 45.0% SVL; tarsal length 26.3% SVL; foot length 38.8% SVL; relative lengths of toes I <II <III V<IV; heels without tubercles; inner metatarsal tubercle weakly developed and elongate; outer metatarsal tubercle absent; webbing formula for the feet: I0–0II0–2III1–3IV2 3 / 4 –2V; no expanded pads on toes.

Color in life. —Edges of lore and head golden with black shades; area below eyes with prominent white marking with yellowish tint; dorsum light greenish-brown with light brown hourglass figure extending from posterior of orbit to top of the sacroiliac joint; hourglass shape ends with distinct horizontal black bean color mark on each side; yellowishgreen marking on each shoulder; flanks black with red tubercles, maculated with greenish-yellow blotches, and possessing very prominent dark brown stripe starting from posterior end of orbit to inguinal region; inguinal areas greenish with golden tint; sacroiliac joint to inguinal region of flanks, golden yellowish-green; dorsal sides of limbs light brown; forearm, femur, tibia–fibula, and tarsus with distinct dark spot encircled with golden-yellowish-green color; venter opaque; throat golden-yellow; abdomen, ventral side of arms and legs pinkish with scattered yellow and black blotches; webbing in hand and foot translucent.

Color in preservative. —In preservative, the animal appears dull because it has lost its golden-yellowish and greenish colors. The hourglass pattern has turned gray. The venter has lost all of its pinkish and golden-yellowish shades and turned a greenish-white.

Etymology. —The specific epithet refers to the Minangkabau or Minang ethnic group inhabiting the region where the new species was found.

Common name. —Minangkabau Puppet Toads.

Province, Sumatra (MZB 25738). A color version of this figure is available online.

Distribution and natural history. — Sigalegalephrŋnus minangkabauensis is known only from Gunung Kunyit from an elevation of 1428 m ( Fig. 4 ). The holotype was found perched on a leaf ~ 1.25 m above ground, by the edge of a forest stream at 2015 h. Before collecting it, ENS watched the specimen move in reverse toward the edge of the leaf on which it was perched, where it defecated (outside of the surface of the leaf), and then return to its original position. The holotype weighed 0.5 g.

Figures

FIG. 7.—(A) Lateral, (B) dorsal, and (C) ventral view of the holotype of Sigalegalephrŋnus minangkabauensis from Gunung Kunyit, Sumatera Utara

FIG. 4.—Map of Sumatra with topographical relief showing localities where members of the new genus of toad (Sigalegalephrŋnus) were found.