Nyctibatrachus sholai, Radhakrishnan & Dinesh & Ravichandran, 2007

Radhakrishnan, C., Dinesh, K. P. & Ravichandran, M. S., 2007, A new species of Nyctibatrachus Boulenger (Amphibia: Anura: Nyctibatrachidae) from the Eravikulam National Park, Kerala, India, Zootaxa 1595 (1595), pp. 31-41 : 32-38

Nyctibatrachus sholai sp. nov.

( Figures 1, 2; Tables 1, 2)

Holotype: Zoological Survey of India, WGFRS, Calicut (ZSI/ WGFRS /V/A 611), an adult male collected at Kolukkumalai shola forest (Eravikulam National Park, Idukki District , Kerala State, South India) by R.M. Sharma and C. Radhakrishnan, on 4 th March 1995. The locality is situated approximately 2200 m above sea level (10 0 12’ N and 77 0 02’ E).

Paratypes: Five additional specimens collected from different localities within the Eravikulam National Park: ZSI/WGFRS/V/A 612 collection data same as that of holotype; ZSI/WGFRS/V/A 616 from Turner’s valley shola forest on 5 th March 1995 and ZSI/WGFRS/V/A 613 to 615 from Bhimanada shola forest on 6 th March 1995.

Diagnosis: A small species of Nyctibatrachus (SVL 16.0 to 22.1 mm), diagnosable from congeneric species by a combination of characters: skin with glandular corrugations; head wider than long; snout not projecting beyond mouth; irregular longitudinal corrugations on the dorsum extending up to arms and thighs on the dorsum; supratympanic fold faint; a fold from posterior corner of eye to angle of jaw clearly defined; lower eyelid covering half of the eye; tympanum partially visible; webbing on toes ¼ th reaching penultimate subarticular tubercle of 3 rd toe; tips of digits and toes flattened into minute disks with dorsal longitudinal grooves; and femoral glands present.

Description of the holotype: Some morphometric data are given in Table 1. The holotype is in good condition generally, with an exception of 10 mm longitudinal incision in the ventral region of vent because of very smooth skin of belly. On preservation, the skin of the body is roughened a little, due to dehydration and also faded to a browning in color.

A small species of Nyctibatrachus, SVL 22.1 mm; habitus short, stout, and robust; head broader than long (HW/HL = 1.29), depressed; snout rounded, sloping forward in lateral view; snout with a fold starting from snout tip to above the level of nares; nares oval, positioned laterally than dorsally, nearer to orbit of eye than to snout tip (EN/ES = 0.34); internarial distance more than twice the distance from anterior corner of eye to nostril (IN/EN = 2.27); eyes proportionately large (ED/HL = 0.50), its diameter more than twice the distance from eye to nostril (ED/EN = 2.81); upper eyelids narrow, granular, lower eyelid covering half of the eye; skin not co-ossified to the boney elements of the cranium; interorbital width nearer to double the width of upper eye lid width (IO/UE = 1.92); canthus rostralis absent; loreal region sloping; maxillary teeth present; a weak ‘W’ shaped symphysial knob on anterior edge of mandible; mouth extending up to posterior corner of the eye; tongue bifid apically without a papilla, free posteriorly; choanae located close to anterior edge of palate; vomerine ridges small, very close, more or less horizontal, teeth indistinct; contracted pupil rhomboidal; a ridge extends from upper lip along the midline of snout tip to the region between the nares; a small horizontal fold in the interorbital space; supratympanic fold faint and a distinct small fold from posterior corner of eye to angle of jaw; tympanum indistinct and a small fold from posterior corner of eye to angle of jaw; dorsum, upper eye lid and upper surface of limbs with small irregular transverse longitudinal folds; ventrally smooth.

* Holotype.

Arm short and stout; fingers short and slender, lacking webbing; relative length of fingers (longest to shortest): III>IV>II>I; tips of fingers dilated into small disks without circummarginal grooves; longitudinal dorsal grooves present on disks; subarticular tubercles moderate, rounded one each on first and second fingers, and two on third and fourth; palmar tubercles indistinct; hind limbs relatively short and stout, failing to overlap when folded at right angles to axis of the body; toes slender, long; webbing ¼ th, web reaching penultimate subarticular tubercle of 3 rd toe, webbing formula (Dubois, et al., 2001) I 2–2 II 1¾–2 III 1½–2 IV 2–1 V; relative length of toes (longest to shortest): IV>III>V>II>I; toe tips dilated in to minute disks without circummarginal groves; longitudinal dorsal grooves present on disks; subarticular tubercles moderate, rounded numbering one on first, second and fifth toes; two on third and three on fourth toe; small inner metatarsal tubercle; outer metatarsal tubercle absent; tarsal fold absent. Femoral gland present, covering much of the under surface of thighs (8 mm x 2 mm).

Colour: In life dorsum uniform brown with metallic green dots over the back on the glandular corrugations; rhomboidal pupil black, with golden yellow sclera, venter deep orange except for lips, palm and foot, which is brown. In preservative dorsum uniform chocolate brown; throat, light orange with brown lips; ventrally uniform light orange, except for palm and foot which is chocolate brown with the continuation of the dorsum colour; no barring on hind and fore limbs; tongue unpigmented.

Etymology: The species is named after the habitat type “Shola” from where the new species was collected inside the shola-grassland complexes of Eravikulam National Park.

Additional information from paratypes: Morphometric data are given in Table 1. Paratypes range from 16.0 mm to 18.4 mm in SVL; in all the external morphological characters they are similar to holotype except for number of vomerine teeth and body colour patterns. Each vomerine ridge has 4 vomerine teeth in types (ZSI/ WGFRS /V/A 612) and (V/A 614) and 3 vomerine teeth in (V/A 616), (V/A 613) and (V/A 615). Colour variations are observed among the types (V/A 613), (V/A 614), and (V/A 616) with a pair of parallel dorsolateral white bands starting behind the upper eye lid to the region of shoulders, with a very faint horizontal white band giving a general appearance of ‘H’ without any dorsolateral glandular folds .

Sexual dimorphism: Adult males can be separated from juveniles and adult females by their bilaterally symmetrical, elongated femoral glands on the inner side of thighs.

Ecological notes: All the type series were collected during the day time, the type series V/A 611 and V/A 612 was collected along the slow-flowing streams of shola patch of Kolukkumalai, where tree canopy is high; V/A 616 was collected in the shola patch of Turners Valley; V/A 613, V/A 614 and V/A 615 was collected in the higher elevated mountain ranges of Bhimanada shola-grassland complexes, specimens were found in the vicinities of water, under the shade cover camouflaging with dead leaves and stones in the canopy covered shola complex.

Comparisons: We compare the new species with all congeners from the original descriptions of the holotype from the literature, listing only diagnostic characters of the respective species.

N. major Boulenger, 1882 , as the type description is too meager, detailed description and morphometric data for comparisons are adopted from Pillai (1978), adult size large, SVL 23.0 mm to 36mm (adult size small, SVL 16.0 mm to 22.1 mm in N. sholai ); dorsum with close set of folds with pale dorsolateral bands (dorsum with irregular scattered longitudinal glandular folds in N. sholai ); throat longitudinally corrugated, generally brown and belly with faint transverse folds (throat and belly smooth with light orange colour in N. sholai ); fingers and toes with disks but only toe disks with circummarginal grooves (both finger and toe disks without circummarginal groves in N. sholai ); toes ¾ th webbed (toes ¼ th webbed in N. sholai ). Pillai (1978) considered Rana travancorica Annandale as junior synonym of N. major in the redescription of N. major and its tadpole study.

N. beddomii ( Boulenger, 1882) , adult size small, SVL 13.6 mm to 17.1 mm (adult size more, SVL 16.0 mm to 22.1 mm in N. sholai ); dorsum and venter smooth (dorsum with irregular scattered longitudinal glandular folds in N. sholai ), upper eyelid with conical tubercles (upper eye lid granular in N. sholai ); no grooves on finger disks (fingers with longitudinal grooves in N. sholai ); toe disks with both longitudinal and circummarginal grooves (toe disks with only longitudinal grooves in N. sholai ); webbing absent in toes (toes ¼ th webbed in N. sholai ); fore and hind legs strongly barred (fore and hind legs without cross bands in N. sholai ), as the type description is very brief detailed descriptions and morphometric data for comparisons are adopted from Inger et al. (1984). These authors treated Nannobatrachus anamalaiensis Myers as junior synonym of N. beddomii on comparison with the cotypes of N. beddomii and type series of N. anamalaiensis , latter Dubois (1986) synonymized the genus Nannobatrachus with Nyctibatrachus by implication.

N. sanctipalustris Rao, 1920 , adult size large, SVL 39.0 mm (adult size small, SVL 22.1 mm in N. sholai ); dorsum with semicircular close set of folds (dorsum with irregular scattered longitudinal glandular folds in N. sholai ); nostrils equidistant between snout tip and orbit (nostrils nearer to orbit than to snout tip in N. sholai ); toes more than ½ webbed (toes ¼ th webbed in N. sholai ); dorsum reddish brown above with barred limbs (dorsum chocolate brown uniform without any cross bars on the limbs in N. sholai ); throat bronze, abdomen yellow (throat and abdomen smooth with light orange colour in N. sholai ). N. sanctipalustris modestus Rao, 1920 was described with N. sanctipalustris as new variety, Chanda and Das (1997) synonymised the latter with N. sanctipalustris by comparing both the holotypes.

N. sylvaticus Rao, 1937 , adult size large SVL 42.0 mm (adult size small, SVL 22.1 mm in N. sholai ); head as long as broad or slightly longer (head broader than long in N. sholai ); canthus rostralis angular, well marked and loreal region concave (canthus rostralis absent and loreal region sloping in N. sholai ); toes more than ½ webbed (toes ¼ th webbed in N. sholai ); inner metatarsal tubercle spade like (inner metatarsal tubercle glandular and oval in N. sholai ); dorsum brown with cross bars on both the limbs (dorsum chocolate brown uniform without any cross bars on the limbs in N. sholai ).

N. kempholeyensis ( Rao, 1937) , adult size small, SVL 18.0 mm (adult size large, SVL 22.1 mm in N. sholai ); symphysial knob absent (a weak ‘W’ shaped symphysial knob present in N. sholai ); nostrils equidistant between the snout tip and anterior corner of eyes(nostrils nearer to orbit than to snout tip in N. sholai ); finger tips dilated into spherical balls (finger disks prominent with longitudinal grooves in N. sholai ); heels do not meet when the limbs are folded in to right angles to the body (heels just meet when the limbs are folded in to right angles to the body in N. sholai ); webbing absent in toes (toes ¼ th webbed in N. sholai ); dorsum bronze or black, in males throat yellowish, that of female finely marbled (dorsum chocolate brown uniform, throat and abdomen smooth with light orange colour in N. sholai ).

N. humayuni Bhaduri and Kripalani, 1955 , adult size large, SVL 41.0 mm (adult size small, SVL 22.1 mm in N. sholai ); nostrils midway between the snout tip and anterior corner of eyes(nostrils nearer to orbit than to snout tip in N. sholai ); interorbital space broader than internarial space (interorbital space is equal to internarial space in N. sholai ); vomerine patches with 6–8 teeth (vomerine patches with indistinct teeth in N. sholai ); tips of fingers and toes very well dilated in to disks with circummarginal groves (both finger and toe disks without circummarginal groves in N. sholai ); toes fully webbed (toes ¼ th webbed in N. sholai ); inner metatarsal tubercle elongated (inner metatarsal tubercle glandular and oval in N. sholai ); dorsum with very small vermiculated folds (dorsum with irregular scattered longitudinal glandular folds in N. sholai ).

N. deccanensis Dubois, 1984 , adult size small, SVL 22.0 mm (adult size sub equal, SVL 22.1 mm in N. sholai ); dorsal skin smooth with glandular folds on the head (dorsum with irregular scattered longitudinal glandular folds al along the body in N. sholai ); tips of fingers and toes without disks (disks present on both the fingers and toes but without circummarginal groves in N. sholai ); toes ½ to ⅔ webbed; (toes ¼ th webbed in N. sholai ); dorsum brown with blackish markings (dorsum uniform chocolate brown in N. sholai ). N. deccanensis Dubois is a replacement name for Rana pygmaea Gunther (= N. pygmaeus ).

N. aliciae Inger, Shaffer, Koshy and Bakde, 1984 , adult size medium, SVL 32.0 mm (adult size small, SVL 22.1 mm in N. sholai ); internarial distance about 1/3 rd the distance from the tip of the snout to eye IN/ ES=0.33 (IN/ES = 0.78 in N. sholai ); upper eyelids very reduced covering less than one quarter of the eye ball (upper eye lids narrow in N. sholai ); supratympanic fold distinct (supratympanic fold weak in N. sholai ); fin- ger and toe tips with well developed disks with circum marginal grooves (disks present on both the fingers and toes but without circummarginal groves in N. sholai ); toes ¾ th webbed (toes ¼ th webbed in N. sholai ); subarticular tubercle well developed (subarticular tubercle moderate in N. sholai ); white nearly small outer tubercle present (outer tubercle absent in N. sholai ); throat with a series of longitudinal ridges (throat uniform smooth in N. sholai ); both hind and forelimbs barred (limbs without any cross bars in N. sholai ); femoral glands weak (femoral glands strong and distinct in N. sholai ).

N. vasanthi Ravichandran, 1997 , adult medium sized, SVL 23.5 mm (adult size small, SVL 22.1 mm in N. sholai ); skin smooth (skin with short irregular longitudinal folds in N. sholai ); head broader than long HL/ HW=0.81 (HL/HW= 0.77 N . sholai); tibia relatively shorter TBL/SVL= 0.50 (tibia relatively long TBL/SVL= 0.40); loreal region somewhat concave (loreal region sloping in N. sholai ); toe webbing reaching the base of disk (toes ¼ th webbed in N. sholai ); flanks with dermal folds (flanks without any dermal folds in N. sholai ); inner metatarsal tubercle narrow and elongate (inner metatarsal tubercle glandular and oval in N. sholai ); limbs with cross bars (limbs uniform without any cross bars in N. sholai ).

N. karnatakaensis Dinesh, Radhakrishnan, Reddy and Gururaja, 2007 , adult size largest among the known species of Nyctibatrachus, SVL 66.0 mm to 84.0 mm( Krishnamurthy et al., 2001) (adult size small, SVL 16.0 mm to 22.1 mm in N. sholai ); skin highly vermiculated with close set of folds (skin with short irregular longitudinal folds in N. sholai ); toes completely webbed (toes ¼ th webbed in N. sholai ); subarticular tubercles on toes distinct and oval (subarticular tubercles moderate in N. sholai ); inner metatarsal tubercle elongated (inner metatarsal tubercle glandular and oval in N. sholai ); dorsum color brown mottled with yellow (dorsum chocolate brown uniform in N. sholai ). Dinesh et al., (2007) considered N. hussaini Krishnamurthy, Reddy and Gururaja, 2001 as synonym of N. karnatakaensis .

N. petraeus Das and Kunte, 2005 , adult size large, SVL 43.2 mm (adult size small, SVL 22.1 mm in N. sholai ); skin with close set of folds (skin with short irregular longitudinal folds in N. sholai ); snout projecting beyond mouth (snout just sloping forward in lateral view in N. sholai ); waist narrow (waist not constricted in N. sholai );finger and toe tips with well developed disks with circummarginal grooves (disks present on both the fingers and toes but without circummarginal groves in N. sholai ); toes completely webbed (toes 1/4 th webbed in N. sholai ).

N. sholai sp. nov. possesses certain common characters with N. minor Inger , et al., 1984, such as, small adult size SVL 15.1 to 21.5; rounded snout; absence of canthus rostralis; having internarial distance approximately equal to interorbital distance; reduced upper eye lid; faint indistinct supra tympanic fold; barely visible tympanum; disks of finger and toe tips with disks, but without circummarginal grooves; weakly developed subarticular tubercles; tibia 0.40 of SVL and in having small glandular inner metatarsal tubercle, but differs from N. minor in having stout and robust habitus (vs squat and slender habitus); nostrils nearer to eye than to snout tip (vs nostrils midway between eye and snout tip); interorbital distance about two times the width of upper eye lid IO/UE = 1.9 (vs interorbital distance three times the width of upper eye lid IO/UE = 3.0); all the finger disks with distinct longitudinal dorsal groove (vs finger disks with weak longitudinal dorsal grooves); subarticular tubercles moderate, but distinguishable on both fingers and toes (vs subarticular tubercles weak, barely distinguishable from the ventral surface of both fingers and toes); toe webbing ¼ th, web reaching penultimate subarticular tubercle of 3 rd toe (vs no vestige of webbing); dorsum including upper eye lid and upper surface of limbs with glandular irregular transversely set longitudinal folds, folds with only projections of arms of ‘X’ are visible without any intersection on the anterior back of the dorsum without dorsolateral glandular folds (vs dorsolateral glandular folds distinct, with a ‘X’ patterned ridge over the anterior back of the dorsum); femoral glands present in sexually mature males (vs femoral glands absent in mature males). Bodyproportion comparisons are given in Table 2.