Philautus amboli, Biju & Bossuyt, 2009

Biju, S. D. & Bossuyt, Franky, 2009, Systematics and phylogeny of Philautus Gistel, 1848 (Anura, Rhacophoridae) in the Western Ghats of India, with descriptions of 12 new species, Zoological Journal of the Linnean Society 155 (2), pp. 374-444 : 392-394

PHILAUTUS AMBOLI SP. NOV.

( FIGS 2, 6B, 7A–D, 8, 9; TABLE 2)

Type material: Holotype, BNHS 4398 , an adult male, SVL 33.4 mm, collected by SDB on 24 August 2001 from Amboli , Sawantwadi District, Maharashtra, India; paratypes, BNHS 4399–4403 , five adult males, collected along with holotype, and BNHS 4535 , an adult female collected by SDB on 15 August 2004 from the same locality as the holotype.

Other material studied: BNHS 4542, an adult male, from Castle Rock; BNHS 4475, an adult male, from Londa, and BNHS 4534, an adult male from Jog Falls ( Table 2).

Diagnosis: Philautus amboli sp. nov. can be distinguished from known congeners by the following combination of characters: (1) medium male adult size (27.6–34.1-mm long), large female adult size (37.5-mm long); (2) body rather robust; (3) discs of fingertips much enlarged ( FDIII = 2.6 ± 0.1 mm vs. FWIII = 1.0 ± 0.1 mm, N = 5); (4) upper 2/3 of tympanum dark brown; (5) throat lemon yellowish with minute black spots.

Philautus amboli sp. nov. can be easily differentiated from all of the known species of Philautus from the Western Ghats by its dark-brown tympanum (both in life and in preservation), in combination with a relatively larger snout–vent length ( Figs 8, 9). However, because of the tympanum coloration, P. amboli sp. nov. could be confused with two other species that have dark-brownish black tympanums from this region, Philautus kani sp. nov. and Philautus wynaadensis Jerdon, 1853 , and three species from Sri Lanka, Philautus leucorhinus (Lichtenstein & Martens, 1856) , Philautus nasutus (Günther, 1869) , and Philautus temporalis (Günther, 1864) . Philautus amboli sp. nov. differs from P. kani sp. nov. and P. wynaadensis by the relatively larger snout–vent length of the adult male ( Fig. 9), SVL 31.1 ± 2.3 mm, N = 9 (vs. the small adult male SVL 20.6 ± 1.5 mm, N = 7, in P. kani sp. nov.; medium adult SVL 25.7 ± 1.5 mm, N = 7, in P. wynaadensis ), rather robust body (vs. slender in both species), throat lemon yellowish with black spots (vs. fleshy white or grey in P. kani sp. nov.; light-greyish yellow with minute spots in P. wynaadensis ), restricted distribution in Maharashtra and Karnataka states (vs. both species endemic to Kerala and Tamil Nadu). More specifically, P. amboli sp. nov. is distinct from P. kani sp. nov. by its head width, which is almost equal to its length ( Fig. 9): HW 11.6 ± 0.8 mm vs. HL 11.7 ± 0.8 mm, N = 9 (vs. head shorter than its length, HW 7.2 ± 0.4 mm vs. HL 8.0 ± 0.5 mm, N = 7), canthus rostralis indistinct (vs. rounded), third finger disc 2.6 times wider than finger, FDIII = 2.6 ± 0.1 mm, vs. FWIII = 1.0 ± 0.1 mm, N = 5, Figure 7A and C (vs. third finger disc 1.7 times wider than finger, FDIII = 1.0 ± 0.1 mm, vs. FWIII = 0.6 ± 0.1 mm, N = 5, Fig. 43A and C), uniformly shagreened dorsum, Fig. 8 (vs. scattered spinular granulation throughout, Fig. 44A); and differs from P. wynaadensis by its head width being almost equal to its length ( Fig. 9), HW 11.6 ± 0.8 mm vs. HL 11.7 ± 0.8 mm, N = 9 (vs. head shorter than length, HW 8.7 ± 0.7 mm vs. HL 9.7 ± 0.5 mm, N = 7), snout pointed in ventral view (vs. snout subelliptical), third finger disc 2.6 times wider than finger, FDIII = 2.6 ± 0.1 mm vs. FWIII = 1.0 ± 0.1 mm, N = 5 (vs. third finger disc 1.8 times wider than finger, FDIII = 1.3 ± 0.1 mm vs. FWIII = 0.7 ± 0.1 mm, N = 5), shank almost equal to thigh (ShL 15.1 ± 0.7 mm vs. TL 15.2 ± 0.7 mm, N = 9 (vs. shank longer than thigh, ShL 13.4 ± 0.7 mm vs. TL 12.6 ± 0.7 mm, N = 7), uniformly shagreened dorsum (vs. scattered spinular granulation throughout, Fig. 64A). Philautus amboli sp. nov. differs from P. leucorhinus , P. nasutus , and P. temporalis by its relatively larger SVL 31.1 ± 2.3 mm, N = 9, male, and SVL 37.5 mm, N = 1, female (vs. SVL 20.0 mm, subadult female, holotype ZMB 3057, in P. leucorhinus , Fig. 65A; SVL 17.3 mm, male, holotype BMNH 1947.2.6.21, in P. nasutus , Fig. 65B; SVL 31.0 mm, female, lectotype BMNH 1947.2.6.9, in P. temporalis ; rather robust body (vs. slender in all the three species), the absence of vomerine teeth (vs. presence in P. temporalis ), and absence of calcar on the tibiotarsal articulation (vs. present in P. nasutus ).

Description of the holotype (all measurements in mm): Medium-sized frog (SVL 33.4) with a rather robust body ( Fig. 7A); head length (HL 12.0) equal to width (HW 12.0; MN 10.2; MFE 8.1; MBE 4.3); outline of snout in dorsal and ventral views pointed, snout length (SL 4.8) slightly longer than horizontal diameter of eye (EL 4.5) ( Fig. 7B); canthus rostralis indistinct, loreal region acute to obtuse; distance between posterior margins of eyes (IBE 10.5) 1.8 times that of distance between anterior margins of eyes (IFE 5.7); tympanum (TYD 2.1) distinct; supratympanic fold distinct, from posterior corner of upper eyelid to near the shoulder ( Fig. 7B); tongue without lingual papilla.

Forelimb (FLL 6.5), shorter than hand (HAL 9.7; TFL 5.4); fingers without lateral dermal fringe, webbing absent; subarticular tubercles prominent, rounded, double in II, single in I, III, and IV, III2 and IV2 relatively smaller ( Fig. 7C); prepollex rather distinct, oval; palmar tubercle single, oval, distinct; supernumerary tubercles present on fingers III and IV ( Fig. 7C); nuptial pad present, prominent, slightly spinular ( Fig. 7C).

Hindlimbs moderately long, shank (ShL 15.8) almost as long as thigh (TL 15.9), longer than distance from base of internal metatarsal tubercle to tip of toe IV (FOL 12.9); distance from heel to tip of toe IV (TFOL 21.3); webbing moderate ( Fig. 7D); reaching below the second subarticular tubercle on the inside, and up to the second subarticular tubercle on the outside of toe IV; dermal fringe along toe V absent; subarticular tubercles rather prominent, rounded, simple, IV3 and V2 smaller; supernumerary tubercle present on all toes.

Skin of snout and between eyes shagreened, upper eyelids shagreened with a few granular projections ( Fig. 7A), side of head shagreened to slightly granular, anterior and posterior parts of back shagreened, upper and lower parts of flank shagreened, horny ridge from snout to vent ( Fig. 8); dorsal part of forelimb, thigh, leg, and tarsus shagreened; throat and chest shagreened to granular, belly and thigh granular.

Colour of holotype: In life: dorsum uniform blackish brown ( Fig. 8), snout much darker, loreal and tympanic region blackish, upper two-thirds of tympanum dark-blackish brown, lateral side light brownish with numerous dark black spots; iris upper half lightgolden brownish, lower half dark-golden brownish; limbs dorsally brown, forelimbs and hindlimbs with obscure brownish black cross bands; ventral side light greyish with variable size of brownish grey specks, especially on the side of limbs; throat distinctly lemon yellow with blackish specks, foot and hand greyish, webbing greyish.

In preservation: dorsally uniform blackish brown, tympanic region dark brownish, abdominal region light grey with dark spots; ventral side uniform greyish with dark-brownish irregular spots united in patches.

Variation: Measurements of ten specimens, including the type series, are given in Table 2.

Etymology: Named after Amboli, where the type series was collected. Amboli is treated as an invariable noun in apposition to the generic name.

Distribution and natural history: Amboli and Amba in Maharashtra; Castle Rock, Londa, Jog Falls- Mavingundi, and Kudremukh-Malleshwaram in Karnataka, ( Fig. 6B, Table 1). Five out of seven specimens from the type series were collected from the ground near disturbed evergreen forest patches. The remaining two were collected in amplexus from vegetation about 1-m high. The vocal sac is large and transparent when calling. All were collected during a rainy evening after 19:00 h.