Ghatixalus magnus, Abraham, Robin Kurian, Mathew, Jobin K., Cyriac, Vivek Philip, Zachariah, Arun, Raju, David V. & Zachariah, Anil, 2015

Abraham, Robin Kurian, Mathew, Jobin K., Cyriac, Vivek Philip, Zachariah, Arun, Raju, David V. & Zachariah, Anil, 2015, A novel third species of the Western Ghats endemic genus Ghatixalus (Anura: Rhacophoridae), with description of its tadpole, Zootaxa 4048 (1), pp. 101-113 : 103-110

Ghatixalus magnus sp. nov.

( Figs. 2 C, 3, Tables 1 & 2)

Holotype: TNHM (H) 15.5.20 /80, adult male (81.90 SVL), collected from near a forest stream, 10° 7'53.75"N, 76°59'57.20"E, at elevation 1440m ASL in Kadalar, Idukki district, Kerala, India by Anil Zachariah on 0 5 May 2015.

For

spp. IFE 16.78 15.32 9.62 8.32

Ghatixalus

of

EN

EL

8.16 8.12 7.61 7.34 6.9 4.46 3.83 4.84

specimens SL 13.19 12.25 8.61 7.91

male HL 27.84 25.34 15.76 13.9

adult HW 31.02 28.53 17.82 15.32

of)

mm SVL 81.90 71.54 48.81 45.13

in (

measurements # Museum H () TNHM / 80 15.5.20) (H TNHM / 81 14.8.01 TNHM () H / 12.6.18 68 ( TNHM) H 67 / 12.6.18

Morphometric Sex magnus M Holotype) M magnus ) Paratype asterops M M

1. ((

TABLE Species

Ghatixalus . nov. sp Ghatixalus . sp. nov Ghatixalus Ghatixalus variabilis TMW 8.13 4.88 5.48

BW 12.45 7.90 8.06

HW 12.32 7.74 9.29.

SSD

14.93 8.62 10.96

methods IOD 5.79 3.09 5.20

and

Materials END IND 6.90 2.66 1.05 1.58 1.57 2.63

see

,

abbreviations NSD LTF 4.17 3.42 2.19 1.32 3.23 1.74

For

spp.. UTF 3.34 2.82 3.13

Ghatixalus MTH 13.21 5.73 9.29

of) 39 TMH 8.13 4.75 6.16

Stage

(EL 1.88 1.72 1.84

specimens BH 10.53 6.53 7.49

tadpole TAL 48.01 31.75 34.96

of)

mm

(

in BL

21.48 15.63 16.87

measurements TL. nov 69.70 47.38 51.00

Morphometric Species sp magnus . variabilis asterops

2

TABLE

. Ghatixalus Ghatixalus Ghatixalus Paratype: TNHM (H) 14.8.01 /81, adult male (76.91 SVL), collected from near a forest stream, 10° 7'54.95"N, 76°59'57.89"E, at elevation 1409 m ASL in Kadalar, Idukki district, Kerala, India by Robin Abraham on 0 9 July 2014.

Diagnosis: Ghatixalus magnus sp. nov. can be easily differentiated from its two congeners by the following combination of characters: adult male large, SVL 79.40 ± 1.0, N = 2 (vs. SVL 46.67± 2.0, N = 7 in G. variabilis ; SVL 41.93 ± 2.0, N = 4 in G. asterops ); eye to nostril distance subequal to eye diameter (vs. eye to nostril distance shorter than eye diameter in G. variabilis and G. asterops ); anterio-ventral parts of thighs smooth and posteroventral regions of thighs areolate (vs. ventral surface of thighs areolate in both G. variabilis and G. asterops ); and larger distance from tympanum to eye distance, TYE 2.57± 1.0 (vs. 1.23 in G. variabilis ; 1.30 in G. asterops ). G. magnus sp. nov also differs from G. asterops in that the supratympanic fold extends from the posterior corner of the eye to below the level of the forearm (vs. supratympanic fold extends from the posterior corner of the eye and ending just above the level of the forearm).

Description of Holotype: A large-sized adult male, SVL 81.90 ( Fig. 2 C, 3); head length (HL 27.84) slightly less than width (HW 31.02); snout acutely rounded in ventral aspect, rounded in lateral profile, greatly protruding; snout length (SL 13.19) greater than eye diameter (EL 8.16); canthus rostralis rounded, loreal region obtusely flat; nostrils closer to the tip of the snout than to front of eye; eye to nostril distance (EN 8.12) subequal to eye diameter; interorbital distance (IUE 11.38) greater than upper eyelid width (UEW 6.75); pupil oval, horizontal; tympanum distinct, rounded, TYD 4.75, 1.8 times larger than distance from tympanum to eye (TYE 2.57); supratympanic fold distinct, extending from behind the outer canthus to just below the level of the forearm; symphysial knob Wshaped; lanceolate tongue without lingual papilla; choanal opening oval; pair of vomerine ridges present, directed inwards with a gap between, bearing seven minute round teeth each, odontophores oblique and widely separated between choanae; vocal sac single, median and subgular.

Forelimbs (FLL 19.67) shorter than hand (HAL 25.88); fingers with moderate lateral dermal fringe and bearing large truncate discs with distinct circum-marginal grooves; relative length of fingers: II<III<V<IV; tips of fingers enlarged with disks; subarticular tubercles prominent, rounded, and single on second subarticular tubercle on finger II, weakly developed; supranumerary tubercles present; palmar tubercle prominent, elongate; webbing between fingers prominent; male secondary sexual character: nuptial pads present on fingers II and III, more pronounced on finger III.

Hind limbs long, thighs (TL 41.87) longer than shanks (SHL 39.84); toes long and fully webbed, webbing extending from the disk of toe V and reaching slightly above the distal subarticular tubercle of toe IV, and from the distal subarticular tubercle of toe IV to the disc of toe III; relative length of toes: I<II<III<V<IV; subarticular tubercles well developed, rounded, single on all toes; supernumerary tubercles present.

Skin of dorsum smooth to shagreen; skin of snout, interorbital region and upper eyelids smooth; sides of head finely shagreen, posterior region of tympanum slightly granular; upper parts of flanks finely shagreen, lower parts slightly granular; dorsal parts of forelimbs and hindlimbs finely shagreen; throat, chest and belly areolate; posteroventral regions of thighs areolate, anterio-ventral parts of thighs smooth; ventral surface of shanks and tarsus smooth to granular.

Coloration of Holotype in Life: Dorsum pale rusty-yellowish, reticulated with numerous small bright-yellow irregular blotches; lateral side chocolate brown with creamy reticulations and purplish-turquoise blotches on the groin; loreal region and tympanum pale yellow with a narrow bright yellow band on the canthus rostralis and the upper margin of the tympanic fold converging at the snout tip; iris purplish-grey, with numerous black venations; limbs rusty-yellow with dark brown cross-bands, fingers and toes with cross-bands, discs yellowish, posterior side of thigh brown without reticulation, but a few, scattered yellow blotches; venter dull creamy to grey white; foot and hand light turquoise blue, webbing bluish-brown.

Coloration of Holotype in Preservative: Dorsum dark brown with dull-yellow irregular blotches; lateral sides dark brown with numerous irregular dull-yellow blotches which extend from behind the arms till the groin; tympanum yellowish-brown, upper eyelid grey; venter brownish-grey, lighter at the throat and chest, darkening towards the posterior; hands and feet pale blue.

Etymology: The specific name is latin for 'great', alluding to its larger size as compared to its congeners.

Distribution and Natural History: Ghatixalus magnus sp. nov. has been recorded in the highlands of the southern Western Ghats between the Palakkad Gap and the Shencottah Gap. We found this species in forest near hill streams in Valparai and Parambikulam (in the Anamalai Range), Kadalar (in the High Ranges), Upper Manalar (in the High Wavy Hills) and near Pandianthodu (in the Pandalam Hills) ( Fig. 7 ). The species occurs in midmontane rainforests at elevations between 1350 to 1800 m ASL.

Tadpole description: Three tadpoles at Stages 37–40 were collected from a rocky stream pool on 0 5 May 2015. Sample tissue from a tadpole was DNA sequenced and analyzed to determine its species status. Description is based on a single tadpole at Stage 38 ( Fig. 4 E). The large exotrophic tadpole is depressed and is yellowish-brown, interspersed with golden iridophores, which occur as small specks on the body and as larger blotches on the tail. The ventral and ventrolateral body sides are pale yellowish-brown and less pigmented. Eyes are golden-brown and of moderate size, positioned dorsolaterally and directed more laterally than anteriorly, not visible in ventral view. Naris equidistant from both snout and eye. Spiracle sinistral, ventrolaterally positioned at midbody. Myotomes of the tail musculature are well developed. Tail fin high, pointed at the end. Upper fin higher than lower fin. Oral disc anteroventrally positioned, of oval shape in expanded state, and emarginated laterally. Numerous marginal papillae frame the oral disc ventrally and laterally, but absent on the upper labium. Small submarginal papillae cover the entire inner rim of oral disc. Upper jaw sheath narrow and stretched into a wide U-shaped arch, and lower jaw sheath is narrower and V-shaped. Labial tooth row formula (LTRF) is 10 (6-10)/10(10) ( Fig. 5 C). In contrast, LTRF of both G. variabilis and G. asterops is 7(3-7)/6(1); this matches the old formula for G. variabilis (2:5+5/1+1:5) described by Annandale (1918). Advanced stages of development have been recorded as well ( Fig. 6 ).

Figures

FIGURE 2. Ghatixalus magnus sp. nov.; A. general habitat comprising mid-montane wet forest; B. stream habitat in July near where holotype and paratype were collected; C. holotype in life; D. paratype in life.

FIGURE 5. Oral morphology of tadpole of A. Ghatixalus variabilis (illustration reproduced from Annandale, 1918); B. G. a s t e ro ps; C. G. magnus sp. nov.

FIGURE 6. Late metamorphic stages of Ghatixalus magnus sp. nov.; A. Stage 42; B. Stage 44; C Froglet.

FIGURE 7. Map showing distribution of different Ghatixalus spp.; type locality of G. magnus sp. nov. marked by red star.

FIGURE 4. A. Stream pool habitat in May; B. stage 41 Ghatixalus magnus sp. nov. tadpole in stream pool; live tadpoles (Stage 38) of C. G. variabilis; D. G. asterops; E. G. magnus sp. nov.