Philautus signatus, (BOULENGER, 1882)

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 : 431-433

PHILAUTUS SIGNATUS ( BOULENGER, 1882)

( FIGS 2 , 53C , 55A–C; TABLE 2)

Type material: Lectotype, BMNH 1947.2 .27.36 (ex BMNH 1868.4.3.120), an adult male, SVL 31.5 mm, from ‘ Nilgherries’ i.e. Nilgiri Hills), Tamil Nadu, India.

Other material studied: BMNH 1947.2 . 27.37, an adult male, from ‘ Nilgiri Hills’ ; BNHS 4486 , an adult male, from Coonoor ; BNHS 4487 , an adult male, from Parsons Valley ; BNHS 4488 , an adult male, from Naduvattam ; BNHS 4489 , an adult male, and BNHS 4492 , an adult female, from Avalanche ; BNHS 4558 and BNHS 4491 , two adult males, from Udhagamandalam ( Table 2).

Description of the lectotype: A detailed description of the lectotype was published in Bossuyt & Dubois (2001).

Variation: Measurements of nine specimens, including the lectotype, are given in Table 2. The skin texture is slightly variable: BNHS 4558 has a prominently granular dorsum, whereas BNHS 4489 has a shagreened to sparsely granular dorsum. This species has an array of dorsal coloration from light-greyish brown to dark red, and moreover, the same population shows marked difference in eye markings: iris dark-reddish brown with radiating golden stripes ( Fig. 55A, B ) and light brown iris without stripes ( Fig. 55C ) . BNHS 4488 , light-grey dorsum with dark ‘X’ marking ; BNHS 4558 , uniform reddish brown dorsum with irregular grey spots in life, dorsum turns greyish brown in preservation, light-blackish brown stripe between the eyes, dark-grey ‘X’ mark on dorsum ( Fig. 55C ) ; SDB 089 , dark-brown dorsum with irregular black spots, light-grey stripe in between the eyes making a triangular grey snout with dark irregular brown spots, an inverted blackish brown ‘V’ mark on the middle of the dorsum in life, turns light-greyish brown dorsum with dark markings in preservation, throat with blackish patches ; BNHS 4486 with almost similar markings as the lectotype, uniformly dark-brownish dorsum with an ‘X’ marking and a stripe in between the eyes ; BNHS 4491 with uniform reddish grey dorsum with a light marking ; SDB 098 , uniformly dark reddish with a faint ‘X’ marking on dorsum and limbs ( Fig. 55A ) ; BNHS 4487 , grey dorsum with a light-blackish ‘X’ marking and stripe in between the eyes, scattered white spots on loreal and tympanic regions, lateral side greyish white with light-brown patches, ventral side light grey with irregular light-brown spots, both the limbs have dark cross bands . BNHS 4492 , light reddish with a faint ‘X’ marking ( Fig. 55B ) .

Diagnosis: Philautus signatus can be distinguished from known congeners by the following combination of characters: (1) medium to large male adult size; (2) snout pointed in dorsal view; (3) canthus rostralis acute; (4) tongue with a lingual papilla; (5) flanks and groin flesh white or light-reddish brown, without markings.

Distribution and natural history: Nilgiri Hills and surroundings: Coonoor, Kothagiri, Udhagamandalam, Naduvattam, Avalanche, and Parsons Valley ( Fig. 53C , Table 1). In Avalanche, Coonoor, and Naduvattam, this species was located from heights of about 4 m in shola vegetation. However, in Parsons Valley, calling individuals were observed invariably in the moss-covered earthen bank inside the forest patch.

Remarks: This species was considered to be I xalus variabilis Günther, 1858 (BMNH 74.4.29.458, BMNH 74.4.29.625–652 from Malabar, and BMNH 74.4.29.748–764 from Pycara, by Boulenger 1882).

paratypes, BNHS 4450 – 4452 , three adult males collected along with the holotype.

Other material studied: SDB 016 B, an adult male collected from the holotype locality ( Table 2) .

Diagnosis: Philautus sushili sp. nov. can be distinguished from known congeners by the following combination of characters: (1) medium adult size (SVL 24.9 ± 2.3 mm, N = 5, male); (2) slender to elongate body; (3) head wider than long, HW 10.0 ± 1.0 mm, HL 9.1 ± 0.1 mm, N = 5; (4) snout oval in dorsal view; (5) shank longer than thigh, ShL 13.1 ± 1.3 mm, TL 12.3 ± 1.4 mm, N = 5; (6) ventral side of limbs coarsely granular; (7) lateral side of abdomen light grey with white spots; (8) anterior and posterior part of thighs and groin dark brown.

For comparison with closely related species P. anili and P. sushili sp. nov., see the ‘comparison’ of P. anili .

Figures

Figure 2. Maximum-likelihood phylogram (GTR + G + I; –Ln L = 14 763.97) for the mitochondrial DNA data set of 1488 bp of 34 taxa of Western Ghats Philautus and five outgroup species. Numbers above branches indicate nonparametric bootstrap values under maximum parsimony (MP). Numbers below branches indicate Bayesian posterior probabilities. *Values of less than 50.

Figure 53. Distribution map. A, Philautus ochlandrae; B, Philautus ponmudi; C, Philautus signatus; D, Philautus sushili sp. nov.

Figure 55. Philautus signatus: A, specimen (SDB 098) from Avalanche; B, specimen (BNHS 4492) from Avalanche; C, specimen (BNHS 4558) from Udhagamandalam.